Telephone  +44(0)1298 77211 - Email sales@flowflex.com

FAQs

Frequently Asked Questions

See below answers to our most frequently asked questions.

(1) Technical Specification for the pump?

3 YEAR WARRANTY

30 DAY RETURN POLICY

WRAS APPROVED

PUMP
Pump Weight: 180g (625g including brass fitting)
Centrifugal Pump with Brushless Motor: 75mm x 35mm
Brass Fitting Length: 150mm
Fully Waterproof
To install the pump you need to remove 115mm of straight pipe

OUTPUT
Maximum Head: 5.2m to 6m
Typical Output at 5 Litres per minute:3.2m
Head Power Consumption at 5 Litres per minute: 12.6 Watts
Maximum Sustained Pressure: 4 Bars
Maximum Temperature: 85oC
Flow Switch – Magnetic Rotor Sensed by hall detector
Minimum Flow Switch for detection: 1.5 litres per minute

TRANSFORMER
Input: 100 – 240 Volt 50/60Hz
Output: 12 Volts DC

SPB Pumps run off a 12 Volt power supply, which allows them to be fitted in bathrooms where a traditional 240 volt pump would not be allowed.

The transformer can be plugged into the nearest convenient 3-pin socket without the need for an electrician.

Pumps can be installed up to 15m away from the transformer by using our low voltage 3m extension cables.

Needing only up to 15 watts of power an SPB can run off an electric circuit.

A single transformer can run two pump.

(2) What is the Flow Output for a Shower Power Booster?

Pump Output

Click Link Above to see the head & flow output figures for a single SPB. please be aware that the output from a pump is always a compromise and a balance between pressure and flow provided by the electrical energy you put into the pump.

If a fixed amount of energy is imparted into the water it can increase pressure and it can increase flow and for every application there is an optimum pressure/flow ratio.

In order to give a strong spray pattern a WRightChoice Shower head combined with a single SPB will lose 2.3 metres head in the shower head to create a fast/strong spay pattern and deliver 5.9 litres of water.

Remember that showers mix hot and cold so you will exceed the output of the hot alone in a normal home, but your shower head may not be as good as ours, you may a mixer that is designed for Central European high pressure systems. If you do have problems you can double boost the hot with a SP21S or balance flow with a SP22S.

Max Head: 5.2m to 6m
Typical output at 5 litres per minute: 3.2m
Head Power Consumption at 5 litres per minute: 12.6 Watts
Max Sustained Pressure: 4 Bars
Max Temperature: 85oC
Min Flow for detection: 1.5 Litres per minute

(3) What pumps do you offer?

Shower Power Booster Range

Single Pumps

 

SP1 Manual Pump Suitable for all systems
SP2B Automatic Pump Suitable for all systems (Min Flow Rate 1.5 L/Min)

Single pumps are supplied with 3 Amp Transformer


Double Pump Kits

 

SP21S Auto & Manual Pumps Double Boost your Water Pressure
SP22S Two Auto Pumps Pressurise bot Hot & Cold Feeds

Double Pump Kits are supplied with 1 x 3 Amp Transformer & the cables to connect two pumps.


Upgrade Pumps

 

SP1U Add a Manual Pump to Double Boost your Water Pressure
SP2U Add an Automatic Pump to Balance Hot & Cold Feeds

NO Transformers are supplied with Upgrade pumps.

(4) Manual or Automatic Pump?

Manual pumps need to be turned on and off every time you want to operate the pump. The Manual pump does not rely on flow meaning the pump is suitable for all systems.

Our most popular pump is the Automatic pump which needs a minimum of 1.5 Litres per minute to operate.

If you have this flow rate then the pump will activate each time you turn on a tap or shower. When you turn off the tap or shower the pump will return to its standby mode.

1.5 Litres per minute is very low so most people should be able to operate an Automatic pump. If you don’t have this flow rate you will need a Manual Pump.

To test your flow rate turn your poorest performing tap or shower on full hot and measure, in a jug or bucket, how many litres you get in a minute.

Customers who have needed a manual pump often purchase a remote or timer to operate the pump ‘semi automatically’. Some customers have wired the Manual pump into bathroom lighting or extractor fans – this means the pump will only operate when the bathroom is in use.

 

SP1 Manual Pump Suitable for all systems
SP2B Automatic Pump Suitable for all systems (Min Flow Rate 1.5 L/Min)

(5) Do I need two pumps?

In most situations, a single pump will normally deliver enough pressure. A single pump typically adds 0.5 Bar to the system and will double your flow. For example, if you have 2 Litres per minute the pump will double this to 4 Litres per minute.

We would recommend two pumps in the following situations:

Gravity Hot & Gravity Cold

If you have gravity Hot & Cold feeds we would recommend two pumps to keep the system balanced. Adding a pump to each the hot and cold will boost the whole system and keep the system balanced. If you were to boost just the hot, your mixer tap may not operate correctly as some mixers cannot cope with an unbalanced system.

Gravity Hot & Mains Cold

We would also recommend two pumps if you have a gravity hot supply and a strong cold mains feed. Although you can reduce the pressure of your Mains feed with a PRV, a double boost on the gravity side will add between 0.8 – 1 Bar so should balance the system.

Combi Boilers & Megaflows

We would also recommend installing two pumps if you are boosting a combi boiler or
Megaflow. The double boost is needed to deliver enough pressure to top up your combi boiler or Megaflow.

If you are unsure you can always add to a single pump with our upgrade pumps.

 

SP21S Auto & Manual Pumps Double Boost your Water Pressure
SP22S Two Auto Pumps Pressurise bot Hot & Cold Feeds

(6) What pump do I need? I have Gravity Hot & Cold

Gravity Hot & Cold

A Single Shower Power Booster is sufficient for most installations, pressuring the hot side.

A good mixer tap will balance hot & cold with a pressure differential of 4 to 1.

However, if your hot & cold supplies are both very low pressure (or your mixer is very poor at balancing pressures) we would recommend a pump on both the hot and cold (SP22S).

Recommended Pumps

SP22S An Automatic Pump on the Hot & Cold will boost the whole system and keep the system balanced

SP2B A Single Automatic pump will normally deliver enough pressure

SP1 A Manual pump is suitable for all systems

   

 

 

 

 

(7) What pump do I need? I have Gravity Hot & Mains Fed Cold

Gravity Hot & Mains Fed Cold

A Single Shower Power Booster is sufficient for most installations, pressuring the hot side.

A good mixer tap will balance hot & cold with a pressure differential of 4 to 1.

However, in some homes the mains pressure can be very high, compared to the gravity hot, meaning one pump will not give enough of an increase.

You can either reduced the mains pressure with a PRV or add a second pump to double boost.

Recommended Pumps

SP21S A Manual & Automatic pump on the gravity side will give a double boost

SP2B A Single Automatic pump will normally deliver enough pressure

SP1 A Manual pump is suitable for all systems

 

 

 

 

 

(8) What pump do I need? I have an Electric Shower

Electric Showers

A Single Shower Power Booster will increase the pressure and flow to stop an electric shower from switching off the heating element.

Adding around 0.5 Bar of pressure to the electric shower, a single SPB is often enough for the Electric Shower to work.

If your pressure is exceptionally low then a double boost may be required.

Please note the output of any electric shower is limited by the KW rating. Meaning no matter how many pumps or how much water you supply to the unit it will only heat a specific amount of water:

7.5 KW 3.5 Litres a minute
9.8 KW 4.7 Litres a minute
12.5 KW 6.0 Litres a minute

Recommended Pumps

SP2B A Single Automatic pump will normally deliver enough pressure

SP21S A Manual & Automatic pump will give a double boost

 

 

 

 

 

(9) What pump do I need? I have a Combi Boiler / Megaflow

Combi Boiler / Megaflow

Like electric showers, Combi Boilers & Megaflows are fitted with a pressure sensor and if the pressure falls below 1 Bar it shuts down.

A single Shower Power Booster on the incoming cold feed will only add around 0.5 Bar of pressure.

We would therefore recommend two pumps which will add between 0.8 – 1 bar pressure.

This should be enough of an increase to keep the Combi Boiler / Megaflow operating.

Recommended Pumps

SP21S A Manual & Automatic pump will give a double boost

SP2B A Single Automatic pump will normally deliver enough pressure

 

 

 

 

 

(10) Can the pumps boost a Low Water Mains Pressure?

The ShowerPowerBooster can legally Boost low water mains pressure in the UK and Scotland.

The ShowerPowerBooster supplies the perfect flow for a single shower or tap flow and you will be able to get this water 24/7 everyday of the week provided there is water in the main.

Shower Power Booster Maximum Flow Rate = 9 Litres per Minute

It is illegal in the UK to take too much water, this would also pose a serious risk to your health and the health of your neighbours.

Even if you wanted a big pump to take enough water to run 3 taps at a time please don’t do it as it not only stirs up the mains but collapses the pressure so you neighbours cannot have water and when they do get water it will probably be contaminated.

Since the ShowerPowerBooster limits flow rather than pressure your best choice for boosting mains water pressure into a home is to double boost and use a SP21S so you get maximum pressure without exceeding the 12 litres a minute maximum. The ShowerPowerBooster will work anywhere in the world as it is powered by a transformer which runs from a 110 to 240 ac power supply which converts it to 12 volts, or runs directly from a 12 volt car battery. Outside the UK we recommend you buy 22mm to 3/4 inch adaptors so you can easily connect to existing local pipework.

The reason for limiting the amount of water you can ‘pull’ from a water distribution main is that a large pump with large suction can cause depressurisation of the incoming pipe which will allow contamination, sewage, and other nasties into the pipe and stir up sediment. In England, Northern Ireland, Wales, and Scotland, the original ‘Water Bylaws’ (now the ‘Water Regulations Guide’), set a limit of 12 litres a minute as the maximum rating of a pump to avoid risk of de-pressurisation.

WATER REGULATIONS GUIDE UK (including Water Bylaws 2000 (Scotland)
Page 3.16 Regulation G6.2
Showers and other appliances which are supplied with water from a pump located either upstream or downstream of a mixing valve and capable of delivering more than 0.2 litres a second (12 litres a minute), may not be supplied with water direct from a supply pipe unless written approval has been obtained from the water supplier.

Page 3.16 Regulation R6.2
An installer will need to obtain the Water Supplier’s written permission before any pumped shower drawing more than 0.2 litres a second may be supplied directly or indirectly from a supply pipe.

(11) Can I check my pump before installation?

Yes, we recommend that you carry out the following pre fitting checks:

Plug in the transformer and pumps before fitting, and simply blow through the pump to activate the flow switch (automatic pump only). This was done at the factory, so you should not find a problem, but for peace of mind a pre fitting check is recommended.

For further checks go to YouTube and type ‘Shower Power Booster – Pre Fitting Checks’ or Follow the Link.

The LED light on an SP2B (Automatic Pump) is a useful diagnostic tool:

No LED light – Pump has no power
Constant LED light – Flow switch has power
Slow flashing light – Transformer fault
Fast flashing light – Pump is pumping and water flowing through the pump at a rate greater than 1.5 litres a minute

Please note that after switching off the flow switch will delay switching the pump on again for up to 20 seconds (depending on switching program). This delay is deliberate and allows pumps to deal with air entrained in a system and is not a fault.

A6_Chrome_Shower_Pump_Blue_Led_V1

(12) How do I install the pump?

SPB Pumps can be fitted in most places enabling you to place them where it is easiest to get them. They can be installed at any angle or orientation.

When installing on horizontal pipe please ensure the white motor and blue LED are hanging below the feed. Make sure that the arrow on the body of the pump is in the same direction as the water flow.

See image below for installation details:

SPB-Pipe-installation1

Pumps are designed to fit existing 22mm pipe. We supply 22mm x 15mm 3 piece reducing sets to install the pump on 15mm pipe.

How to use a 3 Piece Reducing Set:

SPB-Pipe-installation2

For other pipes or tricky installations, you can purchase:

  • ¾ Olives
  • 22mm x ¾ Conversion Slip Joints
  • 15mm Slip Couplings
  • 22mm Slip Couplings
  • Copper Inserts

Please note Inserts must be used when using PEX (Plastic) pipe

Pumps are lightweight & compact meaning they can be installed unsupported on existing pipework. They can be installed under the bath, in an airing cupboard, under floorboards and (as they are so quiet) even in a bedroom.

To install, simply remove 115mm of straight pipe, insert the pump & tighten the compression joints.

During installation:

DO NOT hold the white barrel when installing
DO NOT adjust the motor nuts, these are factory set
DO NOT use PTFE Tape
If at all, use jointing compound very sparingly, this can block the filter

See FAQs below for more information regarding where to install pumps.

(13) How do I use the 3 Piece Reducing Set?

Pumps can be installed on either 22mm or 15mm pipe. The body of the pump is 22mm but if you are installing on 15mm pipe we supply 22 x 15mm 3 piece reducing sets to enable installation on 15mm pipe.

How to use a 3 Piece Reducing Set:

SPB-Pipe-installation2

(14) Where do I install my pump? – Gravity System

First Choice for most customers:
SP2B Automatic pump – Single Boost a Whole House Solution

For a Whole House Solution fit the pump next to the hot water cylinder, after the vent pipe: this will boost every tap & shower in the house.

1.-SP2B-on-Gravity-Hot-Diagram---Whole-House


SP2B Automatic pump – Single Boost a Protected Flow Solution

To improve the flow for a specific tap or shower (Protected Flow Solution) install the pump on the feed which supplies the specific tap or shower only. This will maintain the flow even if other taps are being used in the home.

1a.-SP2B-on-Gravity-Hot-Diagram---Protected-Flow


SP22s Two Automatic Pumps – Balanced Flow a Whole House Solution

A single Shower Power Booster is sufficient for most installations, pressurising the hot, which should balance the lower pressure of an existing cold gravity feed or the higher pressure of a mains fed pipe. A good mixer tap will balance hot & cold with a pressure differential of 4 to 1.

If you hot & cold supply are both very low pressure (or your mixer is very poor at balancing pressures), then you may need a pump on both the hot and cold.

The Whole House Solution is often the best for a family home as the benefit is throughout the house.

2.-SP2B-and-SP2U-on-Gravity-Hot-&-Cold-Whole-House-Diagram


SP2s2 Two Automatic Pumps – Balanced Flow a Whole House Solution

The diagram below shows how you can install pumps in different locations. Pumps can be linked with 3m extension cables.

2a.-SP2B-and-SP2U-on-Gravity-Hot-&-Cold-Diagram---Different-Areas

 


WIRE DIAGRAM WITH EXTENSION CABLES

Pumps located in different areas can be connected with 3m Extension Cables.

Please note if you are connecting 2 Automatic pumps then you will need at least 3 x 3m extension cables.

 

SP22s Two Automatic Pumps – Balanced Flow a Protected Flow Solution

The Protect Flow Solution is the best solution for B&B and Hotels as each shower and tap is boosted without a single shower reducing the flow and pressure for others.

3.-SP2B-and-SP2U-on-Gravity-Hot-&-Cold-Protected-Flow-Diagram

(15) Where do I install my pump? - Mixed System (Gravity Hot & Mains Cold)

For most mixed systems there is no problem with an unbalanced hot & cold pressure but if you have a shower mixer which needs a balanced flow, the mixer works best when you balance the hot. In some homes the mains pressure can be very high and this may unbalance the SPB even when the pump is running. In such circumstances a pressure reducing valve on the cold may be required.

SP21S Auto & Manual Pump – Double Boost

The diagram below shows how you can double boost the hot feed when you have a strong mains cold supply.

4.-SP2B-and-SP1U-on-Gravity-Hot-and-Mains-Cold-Diagram

(16) Where do I install my pump? – Combi Boiler

Option 1 of 2 – Inlet Pressure Boost

All Combination Boilers are fitted with a pressure sensor and if the pressure falls below 1.0 Bar the gas is turned off. The SPB can be legally fitted to the mains to increase the pressure and flow o stop this happening.

A single Shower Power Booster on the cold water feed to the Combi Boiler will add only 0.2 to 0.3 Bar of pressure. However a second booster, in series, will give you a double boost adding 0.4 to 0.6 bars to the pressure.

The maximum flow from a Combi Boiler is determined by its KW rating and in winter because water is colder the output is less:

24KW Combi Boiler gives 11.5 Litres a minute (2 Showers)
30KW Combi Boiler gives 14.5 Litres a minute (2.4 Showers)
42KW Combi Boiler gives 20 Litres a minute (3 Showers)

Please note the above maximum outputs of Combi Boilers greatly exceeds the output of the SPB.

The diagram below shows how to double boost the mains cold feed into a combi boiler if you have low mains pressure.

5b.-SP2B-and-SP1U-on-Mains-Supply-for-Combi-Boiler-Diagram-2


Option 2 of 2 – Hot Water Boost

The WRight Choice micro booster is the only pump on the market that can boost the pressure on the hot side of a combi boiler but you must not boost more than the maximum number of showers determined by your boiler.

The WRight Choice micro booster cannot create hot water but it can take enough hot water to create the perfect shower. A good shower needs enough water to wash away the suds and enough pressure to give a nice forceful spray pattern. We aim to give 6 litres a minute and a minimum of 3 metres head to achieve this.

The diagram below shows how a pump on the hot pipe can protect and boost the pressure to any tap or shower.

5e.-SP2B-and-SP1U-on-Mains-Supply-for-Combi-Boiler-Diagram

(17) Where do I install my pump? – Megaflow

Megaflow Hot or Cold Boost

The WRight Choice micro booster is the only pump on the market that can boost the pressure on both the hot side and cold side of a Megaflow.


5d.-SP2B-and-SP1U-on-Mains-Supply-for-Combi-Boiler-Diagram


MegaFlows were introduced as a standard for new properties in order to eliminate low pressure problems but in many cases this is the cause of low pressure problems.

If the water pressure entering your home is low or you need to feed a remote upstairs shower or tap a WRight Choice Micro Booster will protect and boost the pressure.

A Wright Choice micro booster cannot create water but you can protect and boost showers or taps in your home up to the maximum flow entering your property.

Wen others open taps in your home, provided you do not exceed the maximum incoming flow, the shower or tap you protect will continue to flow strong and good.

(18) Where do I install my pump? – Electric Shower

SP21S Auto & Manual Pumps – Double Boost

All Electric Showers are fitted with a pressure sensor and if the pressure of the incoming water main falls below 0.8 to 1 Bar, the electric shower will switch off heating elements. The SPB increases the pressure and flow to stop this happening.

Fitting a single Shower Power Booster will add 3 to 4 metres head to the incoming pressure to the incoming pressure to the electric shower, which is often enough for the Electric Shower to work.

If your pressure is exceptionally low then a double boost may be required.

A single WRight Choice micro booster on the cold inlet of a shower will protect your shower even if someone turns another tap on in your house or if your neighbours share a service to your house.

6b.-SP2B-and-SP2b-on-Mains-Cold-for-Electric-Showers-Diagram

Although one pump is normally enough, the diagram below shows how you can double boost the mains cold supply to an electric shower.

6.-SP2B-and-SP1U-on-Mains-Cold-for-Electric-Shower-Diagram

The maximum flow of an electric shower is determined by its KW power rating and in winter because the cold water is colder the output is less:

7.5KW Electric Shower – 3.5 Litres a minute
9.8KW Electric Shower – 4.7 Litres a minute
12.5KW Electric Shower – 6.0 Litres a minute

Electricity is a very expensive way of heating water so a typical family wanting the luxury of a 6.0 litre a minute shower will spend £230 a year just to heat the water up.

Heating with gas and changing to a ShowerPowerBooster boosted shower could save the cost of the electricity wasted every year.

(19) Where do I install my pump? – Radiator Booster

The WRight Choice Radiator Booster is the perfect solution if you have a dead room or a room in your house that is hard to reach.

SP1-Central-Heating-Flow-Booster

The WRight Choice Radiator Booster is the perfect solution for making the end of run radiator or group of radiators on a ‘lazy’ leg which never runs hot, run hot. They can be used for extending the central heating systems to a newly built extension.

(20) How do I link two pumps?

Two pumps can be linked together to provide either a double boost or a balanced flow – See Wire Diagrams below:

Two Automatic Pumps:

(SP22S or SP2B & SP2U)

WIRE DIAGRAM 1_Page_1


One Automatic Pump & One Manual Pump:

(SP21S or SP2B & SP1U)

WIRE DIAGRAM 1_Page_2


Pumps located in different areas of a house can be linked together with extension cables. 3m extension cables allow the pumps to be up to 15m away from the power source.

Please note that there are 3 cables running between the pumps – you will need a minimum of 3 extension cables if pumps are over 3m apart.

 

 

 

 

 

 

 

 

(21) Problems with my pump: Pulsing Pumps – Airlocks

In any conversation with a customer I like to find out if there is a fundamental problem with the pipework.

Airlocks prevent the full effect of the pumps being received as energy needed to increase flow and pressure is wasted in pushing air about. As the air moves the resistance to flow changes and this can cause pulsing.
This is a real report from a customer survey:

January 14th 2015 – Mr Harrison – Wymondham Norfolk
Problem Reported – Pulsing pump

Reason for Problem
In order to feed the shower a 22mm pipe had been taken from a point near the hot water cylinder – up into the loft – across the loft – and down to the shower. This effectively trapped a column of air which had no way of being vented from the pipe installed.

Solution to Problem
Mr Harrison connected the pipe to the hot water vent pipe in the loft, with the pipe falling all the way to the shower, eliminating trapped air. I received this email just a couple of hours after I left him:

Hi Alan
Thanks for coming around this evening it was nice to meet you, I have changed all the pipework around and so far, so good, we have had two showers and it hasn’t pulsed so looking good. I like fitting these pumps now!

(22) Problems with my pump: Pulsing Pumps – Lack of water

A Shower Power Booster can only pump water if it has water to pump.

In a typical gravity system, the water feeds from the bottom of the cold water tank into the bottom of the hot water cylinder – hot water exits from the hot water cylinder.

From the top of the hot water cylinder, hot water travels horizontally through a 22mm pipe. There is a vent pipe which terminates above the cold water tank, and a pipe which may go down to feed your shower, or your shower may be fed off the vent pipe in the loft.

When you fit a SPB the pump may want to pump double your normal flow. The pump is supplied with water from the cylinder, providing the water from the cylinder can be doubled, the pump pumps continuously.

If the water that is supplied is restricted then the pump starts off pumping what it can get from the cylinder plus some water in the vent pipe. When the vent pipe runs out of water the pump draws a mixture of air and water and it spins ineffectively, so although the motor is still running, the pump stops pumping water.

When the pump stops pumping water the flow from the cylinder fills the vent pipe up again, the pump is re-primed and starts pumping again – cycle repeats.

The sound of the pump varies as the speed increases (trying to pump air), and then decreases (pumping water).

If you disconnect the tap or shower you are trying to improve you could check the flow through a ‘free discharge’.

If this is your problem then look to potential problems in and around your hot water cylinder:

The stop tap on the cold water feed to the bottom of the cylinder is the normal culprit. It may be partially closed or corroded and often you find a new gate valve with an old gate valve left in place on the cold pipe feeding the cylinder.

Other things to look out for is scale in the hot water cylinder, in the cold water tank, airlocks in the cold feed.

(23) Problems with my pump: Pulsing Pumps – Excessive Back Pressure with a mixer

Excessive Back Pressure

If you have a mixer tap or shower which is pulsing then reducing the back pressure may stop it pulsing.

If you do not have a mixer then pulsing pumps are either due to lack of water or in very rare occasions air in the pipes.

There are several steps to identifying where you might have created excessive back pressure and its best to look at the easiest things first unless there are obvious causes of air locks.

Shower Head

The shower head is not the cause of fluctuating pressures but changing the shower head could solve the problem. A shower head will create a back pressure as it restricts the flow deliberately to accelerate the water to create a nice spray pattern. Change the shower head, remove any flow restrictors in the shower head and you may reduce the back pressure and solve the problem. If you physically remove the shower head and it still fluctuates then you know changing the shower head could solve the problem. If it’s a tap it could be a gauze filter on the tap spout that needs removing.

Shower Hose

If it is not the shower head then could it be the shower hose is inadequate. Some shower hoses have an internal bore of 6mm or 8mm and needs to be replaced with a high bore shower hose (minimum internal bore 10mm). Remove the shower hose and the flow still pulses then change to a 10mm hose (but change to a high flow shower hose anyway as it is a good way to reduce hydraulic losses)

Taps

Check the filter in the tap spout and consider cleaning it or removing altogether.

(24) Problems with my pump: Pulsing Pumps – Caused by Mixer (Oversensitive Temperature Cassette)

Mixers are less likely to pulse if you pump both hot and cold but for most people a single pump on the hot gives good shower and the mixer does not pulse. Many mixers which pulse at one temperature and pressure are fine if you change the temperature and pressure.

Thermostatic Mixers have a cassette which may be oversensitive

A thermostatic mixer will try to balance the hot and cold feeds. The mixer will therefore restrict the flows to achieve this.

When a mixer has not reached the temperature it wants, it will prioritise the hot port until hot water arrives. Once hot water arrives at the mixer it will reduce the flow on the hot port and increase the flow on the cold port to try to give the temperature you need. If the cassette is slow to act it may overcompensate and open the cold port too much and close down the hot too much resulting in fluctuating temperature and pressure (pulsing pump).

The degree of fluctuation is affected by temperatures, pressures, and differential pressures between the incoming hot and cold. The shower head and shower hose can also have a dramatic effect, and any single change can eliminate the problem.

We have found that changing from a single pump on the hot to pumps on the hot and cold often solves this problem, reducing temperatures can also work. However, the single most effective solution is to change a shower head to a WrightChoice shower head.

There are plenty of ways to change things. The temperature of a typical hot shower is 42 degrees centigrade. The following table compares the volume of hot and cold water to achieve a 6 litre a minute shower at 42 degrees centigrade:-
Requirements for a 6 litre a minute shower at 42 degrees centigrade:

Temperature of Hot               Temperature of Cold
65 Degrees C                                            15 Degrees C
54% 3.24 litres/min                               46% 2.76 litres/min
3.3 metres head                                      4.4 metres head
60 Degrees                                               15 Degrees
60% 3.6 litres/min                                 40% 2.4 litres/min
2.25 metres head                                    3.8 metres head
55 Degrees                                               15 Degrees
67.5% 4.05 litres/min                           32.5% 1.95 litres/min
2.9 metres head                                      1.9 metres head
45 Degrees                                               15 Degrees
90% 5.4 litres/min                                10% .6 litres min
2.1 metres head                                      4.2 metres head

Troubleshooting and maintenance guides for thermostatic mixers will typically state their mixers will deal with differential pressure of 5:1 however SPB know from experience that some mixers do struggle and within the same brand, make, and model, some mixers cope, others do not.

For one particular customer with a Bristan Shower Mixer he persevered and was delighted when he achieved a ‘perfect shower’ when he double boosted hot and cold to effectively give him mains pressure on the hot and on the cold.

(25) Problems with my pump: Why is my pump noisy?

Big pumps can be noisy but being noisy can also be because the pump is installed wrongly and the noise is cavitation.

Cavitation is the formation of bubbles or cavities in liquid, developed in areas of relatively low pressure around an impeller. The imploding or collapsing of these bubbles trigger intense shockwaves inside the pump, causing significant damage to the impeller and/or the pump housing.

Traditional shower pumps can create a suction of 1.5 metres of head (0.15 bars), they need to draw water directly from a hot water cylinder through a pipe to the pump only. You need an Essex or Surrey Flange drilled into the cylinder. Fit them on the pipe connected to the vent pipe and they will suck in air, fit them too far away from the cylinder and the head loss in the pipework results in cavitation.

I visited a home in Buckinghamshire on the 5th June 2016 and found a classical example of cavitation where a pump was installed in a convenient place in a bathroom – the pump was very noisy, suffering from cavitation and was pulling air in. It was on its last legs, and was the 3rd pump installed in recent times.

Traditional Pump In Bathroom Cavitates and Draws Air

Traditional Pump In Bathroom Cavitates and Draws Air

Traditional Pump In Bathroom Cavitates and Draws Air

A ShowerPowerBooster is not a traditional pump and is designed to never cavitate. You can fit a SPB anywhere.
For this installation I recommended:

1.0 Throw the traditional pump in the bin and put the pipework back the way it was.

2.0 Install a SP22S to boost hot and cold to the problem shower in the bathroom only. This will increase the flow to the shower from 2 litres a minute to 6 or even 8 litres a minute with the right shower head, and a high flow hose.

3.0 The shower hose from the shower mixer to the shower head (and the bath mixer shower), is only 8mm internal diameter. This has no effect as long as you pass just 2 litres a minute as at present, but as soon as you try to put 6 litres a minute or more the head loss will be such that the flow will be limited to as little as 5 litres a minute.A high flow shower hose is great value for money in getting extra flow and pressure.

4.0 The existing shower head is only suitable for high pressure systems. To maximise the flow and pressure a Wright Choice shower head is recommended.

Simple Solutions to Big Problems.

(26) Problems with my pump: Why won’t my pump kick in?

The flow switch for a ShowerPowerBooster will work with around 100mm of head in a free flowing system as unlike a power shower pump the pump is turned on and off using a magnetised flow paddle (a traditional power shower pump asks for 1,000mm).

The pump activation is not due to pressure differential but at 1.5 litres a minute the water paddle revolves and a hall detector measures the number of times the paddle rotates.

We have sold pumps purely to activate at a low flow to increase the flow to make a bigger pump come on so we know what we sell is good but sometimes the flow is below 1.5 litres a minute before the pump flows so there is need to think of a work around:

Change the shower head – the greatest resistance to flow is often the shower head. We sell an excellent shower head so changing to our shower head will often give you enough flow to kick start the pump.

Change the shower hose – if you have a shower hose with an internal bore of 8mm or less, the only fit place for it is in a bin. We sell low cost shower hoses with 10mm internal bore.

Drop the shower head to start it flowing at or above 1.5 litres a minute, then return it to height when the pump starts.
Bypass the flow switch and turn the pump on and off manually at a 3-pin socket, or simply make it come on and off by wiring it into the light switch.

Use a remote control to turn it on and off (we sell these for £10).

Put a second pump on mains cold if the shower receives gravity hot and mains cold. The pump on the cold will automatically turn on the hot through the power bridge.

(27) Can the pumps be returned?

Yes, we exceed the minimum statutory return period of 14 days by offering a 30 day period. We encourage customers to trial the product and guarantee a refund, even if the pump is returned damaged or marked through installation.

Contact us if you wish to return your pump.

Flowflex Components Ltd, Dew Pond Lane, Tongue Lane Industrial Estate, Buxton, Derbyshire, SK17 7LR

(28) Where can I find a plumber to fit my shower power booster?

For some customers the right plumber is you. We have designed the pumps for easy DIY and you should have everything in the box to do the job (the record claimed by a 85 year old man in Norfolk is 8 minutes to fit a pump).

However, if you would like a plumber to fit the booster for you then check our list/map of plumbers experienced in fitting our shower power boosters.

(29) Should I buy a WRight Choice Shower Head, hose or mixer?

The WRight Choice brand ethos is to give you the best solution, and if that solution is simply to change the showerhead and hose rather than fit a pump I sell the best showerheads and hoses to achieve this.

I only sell products that I would want to buy myself if I had the same objective as my customer – maximum performance at minimum cost.
We tested and evaluated showerheads and hoses in the research laboratories of Cranfield University, and we were amazed at the difference a change of showerhead or hose could make to the shower flow. The best showerheads, hoses and mixers for low-pressure situations are very good and the worst very bad, but how would you know a good or bad showerhead or hose or mixer just by looking at it? You cannot, but we test them for you, and guarantee to only sell products which work well with low pressures and all systems.

• Shower Heads that maximise your showering performance whatever flow and pressure you have.
• High Flow Shower Hoses (many new shower mixers come with shower hoses with less than 10mm internal diameter).
• If you start with low pressure my pumps can be used in multiple combinations to incrementally achieve the desired objective whatever your plumbing system.

I have set up a website with information including videos dedicated to Shower Heads, Shower Hoses, and Shower Mixer selection.

Visit The Shower Heads, Hoses & Mixers Comparison Site.

A good shower can be achieved by selling you a hydraulically inefficient showerhead, a hydraulically inefficient shower hose, a hydraulically inefficient shower mixer. As long as you also buy a big shower pump (over 20 times bigger than a SPB), you might have a good shower. The same good shower can be achieved by selling hydraulically efficient showerheads, hoses, mixers, and a small pump.

Even with the best shower hose, a shower can be spoilt by a bad showerhead. Our showerheads give wonderful multispray patterns suitable for any type of shower system as they can be set to 6 different modes to suite personal preference and any type of shower system.

Shower hoses come in different internal diameters. A high-flow shower hose allows higher flows, and will not lose you nearly as much pressure as a small-bore shower hose. Small-bore shower hoses are sometimes cheaper and are great for small electric showers and combi-boilers with high mains pressure. Changing to a high-flow shower hose may have a huge effect. Low-flow, small-bore shower hoses are not advertised as small-bore, and many customers buy them by mistake because they do not know that 2 types of shower hose exist. If the internal diameter of the shower hose is less than 10mm diameter, then it is not a high-flow shower hose.

Showerheads for electric showers create fine jets of water and need much higher pressures to operate (minimum 1 bar = 10 metres head). If you have 1 metre head, there are many showerheads which are designed for that pressure. They will never be as good as a boosted shower, but put a showerhead which is designed to operate on 10 metres head and the results are obvious. Buying the right showerhead is not easy unless you know what you are looking for, but ‘great for combi-boilers’ is a giveaway that it is only suitable for high-pressure systems. A good showerhead will probably have 100 jets and a multi spray pattern. People can buy many showerheads before they get it right, but a good showerhead is as important as a good shower hose or mixer.

Mixer valves blend hot and cold water to give you the right temperature for your shower. Many mixer valves can easily balance hot and cold water pressures in the ratio of 4 & 5 to 1 – others are not very good at dealing with differential pressure and will allow temperatures to fluctuate widely when someone turns a tap on or off elsewhere. Buying a cheap mixer tap is not necessarily a problem, and some of the worst performers are expensive mixer brands, because the parts of the mixers you cannot see can cause considerable head loss.

(30) Do you ever exhibit at shows/exhibitions?

Yes, see the list of upcoming shows and exhibitions.

Can't find the answer to your question?

If the answer to your question isn’t covered below then feel free to get in touch and we will do our best to answer your question for you.
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