The lights on the Shower Power Booster are there to tell you the status of the pump and will diagnose a problem if any. You can tell the age of the pump, if the pump is powered up, if there is flow passing through the pump, and they can diagnose some problems.

The age of the pump.

Colour Of LED Light
An LED light is supplied in the flow switch of all automatic pumps. The colour of the light indicates which model you have:-
Green = 2014 Model or 2016 R&D Model
Yellow = 2015 Model
Blue = 2015 to Date

Status Of Light
No light visible = No power to flow switch.
Please check your power supply and transformer. To check if your power supply is working please plug the transformer directly into the barrel of the pump:-

Constant Light = Power to flow switch
If you are wiring up a single SP2B (one pump) then you know it is wired up correctly if the light shines constant.
If you are wiring up a SP22S (two pumps with a 3 way cable) then you know you have wired them up correctly if both lights shine constantly.

Flashing Light = 1.5 litres or more of water is passing through flow switch.
There is a magnetic water wheel which starts to turn when you have 1.5 litres of water flowing through the pump. When the wheel turns there is a ‘hall detector’ which sends a signal to the microchip in the flow switch, which then allows the transformer to power the pump.

If the light is not flashing
The first thing to check is that you are getting 1.5 litres a minute from your shower head or tap.

If you do not have a measuring jug then you can simply collect the water in a bucket and weigh the bucket before and after. 1 Kg = 1 litre.
Eg. 0.5 Kg in 30 seconds = 1.0 Kg in 30 seconds = 2.0 Kg in 60 seconds = 2 litres a minute.

If you are getting less than 1.5 litres a minute through the flow switch then you need to find out why.

The shower head is the biggest restriction to flow, so perhaps changing your shower head is the solution. First of all take your old shower head off and the flow should increase enough to start the flow switch. If it does not, then it is not the shower head or hose. If it is your shower head we sell the best:-

https://www.showerheadhosesmixers.co.uk/good-shower-heads-mixers-shower-hoses/

If the pump was auto sensing and now it is not, it could be a gradual build up of limescale in the shower head, or an air lock. With the pump running you could remove the shower head to try and flush out the air but do look for places where air could be trapped. If the pipe goes up into the loft, across, and then down, its possibly just air in the pipes.

Light flashing rapidly (with pump running)
Then constant light for 2 seconds
Then light flashing rapidly (repeat – repeat)

This indicates you have air in the system and can be solved by:-
1.0 Flushing out the air or changing the pipework to stop air getting trapped (best solution).
2.0 Fitting a 22mm single check valve before or after the pump. Never use a 15mm check valve (and especially never ever use a 15mm double check valve).

SLOW FLASHING LIGHT
The Shower Power Booster can never burn out and it is also protected by two trips and a fuse in the plug.

The trip which normally activates first is in the transformer and it is often the case that it only thinks the pump is taking too much current.

The trip switches the light off, resets, turns the light on, trips out, resets, trips out (Repeat). It is for this reason that the most likely fault is just an oversensitive trip in the transformer, and you will need a new transformer.

There is also a trip in the pump, but this is likely to be robust so it is unlikely to be this trip at fault.

Finally there could be an actual short in the motor or in the flow switch.

If it only slow flashes when connected to the pump it’s probably the pump motor and you need a new pump motor.

With a constant light and flashing lights when the pump is disconnected, it points the finger at the motor being at fault.

Replacing a motor is easy (and we sell replacement motors):-

To Buy A Replacement Motor Click On This Link