Electric Shower Flow Problem?

[Toki]

I have a problem with my Triton Opal II 10.5kW electric shower. The temperature isn’t constant, it seems to vary in a similar way to a sinusoidal wave. It goes from lukewarm to hot every few seconds.

After further investigation, I took the shower head off and it seems to be linked to the flow of the water. When I select the cold setting on the shower the flow is very steady. However when I press the hot water setting on the shower the flow becomes variable, it sort of pulses out.

My understanding of electric showers is that the water heater is on all the time and it is the variable flow which raises and lowers the temperature. As the flow is constant when the water heater is off (on the cold setting) does this mean there is a problem with the actual shower?

Thanks in advance for your help. If you need more information then just ask.

 

[seco services]

check your stopcock etc is fully open
check the showerhead inner hose is not collapsing.
check the stabiliser valve with showerhead off.
turn to fully cold should be a fast flow
turn to fully hot should be reduced flow.

should like a stabiliser issue.

 

[Tipper]

If you live in a hard water area make sure the holes in the shower head are all clear as a reduced flow will cause the overheat thermostat to repeatedly cut out and remake causing your fluctuating tempetrature.

I gave up on electric showers as they are mostly useless and almost always fail to provide a decent shower.

 

[Toki]

check your stopcock etc is fully open
check the showerhead inner hose is not collapsing.
check the stabiliser valve with showerhead off.
turn to fully cold should be a fast flow
turn to fully hot should be reduced flow.

should like a stabiliser issue.

Thanks for all that.

Stopcock is fully open.
I have removed the shower head and turned on the shower at its coldest setting.

The flow is over 13 litres per minute. However when I turn the temperature of the shower up the flow obviously reduces and starts to spurt out around midway up the range. The flow goes down to around 7 litres per minute at 5 out of 10 temperature setting. If I turn it to fully hot the flow is reduced and really spurts even more. Sorry never measured flow. The installation instructions state the water supply has to be 11 litres per minute, is that when the shower is on the coldest setting?

Is the stabiliser valve just the temperature setting spindle? If so I have done this as described above.

 

[Toki]

If you live in a hard water area make sure the holes in the shower head are all clear as a reduced flow will cause the overheat thermostat to repeatedly cut out and remake causing your fluctuating tempetrature.

I gave up on electric showers as they are mostly useless and almost always fail to provide a decent shower.

I'm not sure about the water, as far as I know I live in a soft water area but wouldn't swear. I took the shower head off to eliminate a problem with that as described above.

I agree about electric showers but am stuck with one for now unfortunately.

 

[Toki]

Anyone got any ideas?

Thanks in advance!