Shower isolation switch

[longdogs]

Hi

I have had a long lasting problem with a customer's electric shower. I didn't install the original shower which worked fine for about five years but when the shower went wrong, I installed another like for like. At the same time, her water company fitted a new water meter.

The shower suffers from low pressure which means that it goes cold during use.

The shower has been checked by Triton - Apparently all ok

The water pressure has been checked by the water company - All ok

I have changed the original plastic pipework for copper (larger bore) and replaced a couple of valves which were not full bore.

So with all the plumbing changes made, there is still the same problem.

My question is: Could the pull switch be causing the problem? When the shower is first switched on, the low pressure light comes on feintly. Is it worth changing the switch. I'm really running out of ideas now.

The shower is 10.5kw and uses 10mm cable

Many thanks

 

[securespark]

Does the switch look damaged by heat or the bright copper dulled or discoloured?

 

[RF Lighting]

It sounds like a water flow issue. Just because there is good pressure, it does not mean there's enough flow.

Have you checked all the inlet filters are clear of scale / dirt / obstructions?

Can you fill a 20 litre bucket from the shower supply and time how long it takes? from this you'll be able to calculate the flow rate, and compare it with the manufacturers requirements.

 

[PrenticeBoyofDerry]

As aboveI would be checking the flow rate and pressure.
An electric shower generally needs a minimum of 1 bar and 8 litres per minute.

 

[longdogs]

Hi

Thanks for replies.

The switch does not look discoloured but is quite stiff and does not always have a definite 'click' when pulled.

The water guy checked pressure and flow outside the house which was fine and said that the problem was inside the house. He ran the shower (without the head - so he didn't take the shower off the wall and run water). The kitchen tap was ok.

I have checked filter several times which is ok.

He found two valves in line which were not full bore, so I replaced those.

I can't find anything else I can change on the pipe work.

It's strange that the original shower was perfectly ok for five years.

I suppose it could be an obstruction as suggested after the new meter was fitted but no idea where it is.

 

[PrenticeBoyofDerry]

Were readings/measurements taken at the shower to confirm suitable flow and pressure?
You could have faulty valves, blockage or scaled pipework.

 

[plugwash]

Was the water meter installed indoors or outdoors? did the water company test the pressure and flow before or after the meter?

 

[longdogs]

Were readings/measurements taken at the shower to confirm suitable flow and pressure?
You could have faulty valves, blockage or scaled pipework.

Readings/measurements through shower. Valves changed (unles there's a hidden one). Pipe to shower from mains feed to tank replaced.

 

[longdogs]

Was the water meter installed indoors or outdoors? did the water company test the pressure and flow before or after the meter?

Meter installed outside and tested after meter.

 

[PrenticeBoyofDerry]

Readings/measurements through shower. Valves changed (unles there's a hidden one). Pipe to shower from mains feed to tank replaced.

So the shower is gravity fed not from rising main? To achieve 1 bar of pressure the tank would need to be 10m above the shower, unless it is pumped.
Could you post make and model of this shower.

 

[longdogs]

Readings/measurements through shower. Valves changed (unles there's a hidden one). Pipe to shower from mains feed to tank replaced.

So the shower is gravity fed not from rising main? To achieve 1 bar of pressure the tank would need to be 10m above the shower, unless it is pumped.
Could you post make and model of this shower.

No it is teed off of rising main feed to tank. It's a Triton T100XR 10.5
http://www.tlc-direct.co.uk/Product...=adwords&kw=&gclid=CL_dy_PS7LoCFVMRtAodX3QALw

 

[longdogs]

Sorry, just realised I'm having a plumbing discussion on the electrics forum. I was wondering if there was a problem with the switch (maybe a loose connection) whether it could affect the power to the shower which might affect the flow switch?

I will have to go back and check again for blockages etc.

 

[RF Lighting]

It's not an electrical issue.

The flow switch monitiors the water flow in the shower. If the flow rate falls below a preset limit, the low flow switch will be operated to protect the shower.

A dodgy electrical supply will not affect it's operation. It only uses electricity to report when it has been operated, rather than to actually operate the device.

 

[longdogs]

Thanks RF. At least I can eliminate the electrical side of it then and go back to plumbing issues.

 

[PrenticeBoyofDerry]

This particular shower requires 1.5 bar and flow rate of 11 litres per minute.
As the shower is directly fed from rising main, firstly check that both the internal and external stop taps are fully open. If they are it could be worth checking for debris in the inlet filter.
I will assume you don't have a pressure gauge or weir cup available for use?