Triton T80 Easy-fit running hot and cold

[LarryN]

Hi,
I've had a Triton T80 Easy-Fit for just over 2 years and it's started running hot then cold. It's been fine before and nothing has changed in terms of plumbing in the house. Set at full power, temperature knob in the middle it'll run for 2 minutes hot, then 1 minute cold, then hot again. The low pressure light is off and the flow doesn't appear to have changed.

I removed the hose and ran it straight from the unit, but it's the same issue. Anyone any idea what the issue might be and whether it's repairable? I'm fairly handy with plumbing and electrics unless you get down to soldering.

Thanks.

 

[Johntheo5]

Assume its a non thermostatic shower?.
If its 8.5kw and the TCO is killing the power then the temperature has to reach 50C, at a present 13.5C mains temperature means the flowrate will have to be as low as 3.33LPM, if the shower temperature is around 38C then the flowrate will be almost 5.0 LPM (4.97). It looks like the TCO (maybe faulty) but easy to rule out low pressure (even though no warning light) first. Could also be a failing solenoid valve coil.

Suggest turning the temperature control fully anticlockwise and measure the flowrate, hold a container under the showerhead in its holder for exactly 15 seconds, measure this with a 1 litre jug or whatever, x4 to get the flowrate in LPM, you should get 7.5/8.0LPM.

 

[CountryFan]

Sounds like imo a scaled heating element or a failed element.

 

[LarryN]

Assume its a non thermostatic shower?.
If its 8.5kw and the TCO is killing the power then the temperature has to reach 50C, at a present 13.5C mains temperature means the flowrate will have to be as low as 3.33LPM, if the shower temperature is around 38C then the flowrate will be almost 5.0 LPM (4.97). It looks like the TCO (maybe faulty) but easy to rule out low pressure (even though no warning light) first. Could also be a failing solenoid valve coil.

Suggest turning the temperature control fully anticlockwise and measure the flowrate, hold a container under the showerhead in its holder for exactly 15 seconds, measure this with a 1 litre jug or whatever, x4 to get the flowrate in LPM, you should get 7.5/8.0LPM.

Sorry for the late reply. So turn to fully cold and measure the output for 15 seconds? I'll try and do that tomorrow to see what I get. The T80 easi-fit is 10.5Kw. Does that make a difference?

 

[LarryN]

Sounds like imo a scaled heating element or a failed element.

Thanks. Debating whether it's worth getting someone in, or getting a new one if it's not the pressure. Seems a bit crap given it's only just over 2 years old.

 

[Johntheo5]

and leave the temperature control in the middle, Sorry for the late reply. So turn to fully cold and measure the output for 15 seconds? I'll try and do that tomorrow to see what I get. The T80 easi-fit is 10.5Kw. Does that make a difference?

A 10.5kW requires a flowrate of 6.14LPM to give a flowtemp of 38C from mains at 13.5C and fall to 4.12LPM to trip the power at 50C, not sure when you say "hot" if you mean very hot, ie 50C when it then runs cold. You might also measure the flowrate with the temperature control at its normal position in the middle, One more test, (temp control in middle), turn the power control to switch off one heating element and see if it continues to remain hot, lukewarm, at around 27C for 5 minutes or more without running cold after a few minutes.

Do you live in a hard water area?

If this schematic (its for the thermostatic version) is similar for yours then if its the TCO (5) that trips the power, the power light (6) will also go out, if its low pressure then the power light will stay on.

EDIT: T80 Easy-Fit is sold as the T80 Fast Fit around here, I have a 9.0kW one and this morning I tripped the TCO by reducing the flowrate, the power light stayed on so I think you can ignore the above.

 

[LarryN]

Ok. I've worked out that I've got the 9.5Kw version of the T80. I've just tested the flow. With it turned fully to cold I'm getting about 7.5LPM. With the heating in the middle about 4LPM. No low pressure warnings. No plumbing has changed in the house for a long time and no-one else around to be doing something else.
I turned the power to 1 and it still ran hot for a couple of mins, then cold for 1 min and then back to hot.
Apparently I'm in a soft water area.

 

[Johntheo5]

7.5LPM is fine turned to fully cold.

Just measured my mains at 11.8C, assuming yours is similar, 9.5kW will give a temperature of almost 46C (45.84), at 4.0LPM, fairly cosy, but still shouldn't trip the TCO (50C). One (Eco) element which is 5.6kW will give almost 32C (31.87) at 4.0LPM, a long way from tripping a healthy TCO.
Since you are handy with electrics I would change the TCO, it won't break the bank at ~ £15/£20.

When you stop showering in any shower, you will hear the TCO clicking off after ~ 10 to 15 seconds.

 

[LarryN]

The diagram I've got looks different.

So you think it would be a replacement for 10? It looks like it unscrews rather than being soldered. https://www.showerspares.com/triton...0-easi-fit-plus-electric-shower-t80-easi-fit/

 

[Johntheo5]

Yes, they are all like that, just give the screws a good squeeze up as the TCO is carrying over 40 amps.