Thermostatic shower problem

[beezo]

Hi guys,

a mate of mine is having trouble with his thermostatic mixer shower. He says its never been right since it was installed and puts it down to his boiler as it a few yesars old now. This shower is a grohe rainshower that cost him £800 so not a cheap one

i had a look at it for him and found it had been plumbed in wrong! the hot was on the right, cold on the left. As its almost impossible to switch the pipes around without destroying his bathroom, i spoke to grohe who told me I could buy a reversible thermostatic cartridge.

anyway, this was ordered and when it arrived I installed it. The controls knob works correctly now, so when i turn it to give me hot water, i get hot water whereas before when I turned it to hot water, i got cold water.

anway that sorted but its still not working correctly.

there just just seem to be any temperature adjust via the control knob, so it either gives bareable hotwater or freezing cold water. Theres no happy medium

can anyone advide what would be causing this to happen? Im doubtful its the boiler as we all know that what ever temperature the boiler gives hw at, the thermostatic valve will mix it at the correct ratio depending on what setting is selected at the control knob

any advice much appreciated

 

[Dan Robinson]

as we all know that what ever temperature the boiler gives hw at, the thermostatic valve will mix it at the correct ratio depending on what setting is selected at the control knob

hhhmmm.... How about telling us what the boiler is before you jump to too many conclusions.

 

[beezo]

as we all know that what ever temperature the boiler gives hw at, the thermostatic valve will mix it at the correct ratio depending on what setting is selected at the control knob

hhhmmm.... How about telling us what the boiler is before you jump to too many conclusions.

boiler is a baxi 80e

 

[Dan Robinson]

Does the boiler modulate properly when the shower is running or does it cycle on and off.

I assume you have followed the instructions and calibrated the shower properly?

what is the showers flow rate? the boiler can only do 11 litres per minute.

 

[beezo]

Does the boiler modulate properly when the shower is running or does it cycle on and off.

I have not noticed the boiler cycling on and off but will check tomorrow. However there doesn not seem to be any problem with the hot water taps

I assume you have followed the instructions and calibrated the shower properly?

i never fitted the shower and no instructions came with the new valve. Ive checked the mi website for the instructions but cannot find them

what is the showers flow rate? the boiler can only do 11 litres per minute.

I would be very suprised if the shower puts out more than 11 litres per min as it is a very fime 'rain shower' head but again, will check

 

[hansthebear]

some showers need a pressure reducing valve fitted to the main if the pressure is over a certain level

 

[Dan Robinson]

there doesn not seem to be any problem with the hot water taps

Irrelevant I am afraid, Showers do not work the same way as other taps. Plus the user of a shower is far more sensitive to temperature fluctuations than the user of a kitchen sink.

i never fitted the shower and no instructions came with the new valve.

Phone the manufacturer. Setting these up correctly is kind of important.

I would be very suprised if the shower puts out more than 11 litres per min

You would be surprised at the misconceptions people have. Unless you have measured it... assume nothing.