Mira Sport 10.8kW Shower

[wobs]

Our electric shower (as above) has stopped working on full power, and will only work on "Eco" mode which looks to be just a medium power.

At full power, it often won't come on hot, or if it does, go very hot.

I tried replacing the thermal switch, but didn't seem to make a difference.

Any ideas what the cause might be?

 

[Johntheo5]

Our electric shower (as above) has stopped working on full power, and will only work on "Eco" mode which looks to be just a medium power.

At full power, it often won't come on hot, or if it does, go very hot.

I tried replacing the thermal switch, but didn't seem to make a difference.

Any ideas what the cause might be?

Its more than likely caused by a too low flowrate, any 10.8kw shower will require a flowrate of 7.2LPM from a now (my) mains temp of 18.5C to give a showering temp of 40C, the thermal cut out (TCO) operates at 48C, so a flowrate of only 5.25LPM.
I would suggest turning the temperature control switch to its coldest setting, you can let the power setting to Eco or cold, hold a container under the shower head (with shower head in place in its holder) for exactly 15secs, measure this with a 1L container, X4, to give the flowrate in LPM.
Have you have cleaned the filter and shower head?.

Eco mode, one element on at 5.4kw will give a showering temp of 40C (from mains at 18.5C) at a flowrate of 3.6LPM and would have to fall to 2.6LPM to trip the TCO at 48C.

That shower should also have a Low Pressure Indicator LED, if this isn't on then definitely the TCO operating (correctly), every time you switch on the shower you should see that LED flashing on for a second or two.

 

[wobs]

I'll give that a go, thanks.

 

[Londoner2]

My Triton 9.5kw on eco mode only produces lukewarm water, only fit enough for a hot day.

 

[muggles]

Haver you changed the shower head? An incorrect shower head can cause this

 

[Johntheo5]

My Triton 9.5kw on eco mode only produces lukewarm water, only fit enough for a hot day.

Eco (1/2 power) mode will either give you half the flow at the same showering temperature or reduced showering temperature at the same flow, I have only used it once/twice when the mains pressure was reduced for maintanance and couldn't run on full power.
Your 9.5kw shower will give a flowrate of 6.3LPM at 40C from mains at 18.5C or, in Eco mode, 3.15LPM at 40C or 6.3LPM at 29.3C or somewhere in between.

 

[Johntheo5]

Haver you changed the shower head? An incorrect shower head can cause this

A scaled up shower head can also cause this but generally this can be is a gradual process and may be noticed by having to gradually turn the temperature control more and more towards the coldest position. Easy enough to check the flowrate with the showerhead on and removed.

 

[Johntheo5]

This might be handy to see what flowrates are required for different shower power outputs, you can input your own values, the problem with TCO tripping generally occurs with high mains temperatures like now.