Faulty Instantaneous Shower

Poulgorm

I have a Triton T90xr instantaneous shower (integral pump). It 18 months old and for the last few weeks, it has become erratic. Basically, the temperature control seems to be faulty: on full flow it can get too hot: then it goes cold or just lukewarm: to get a proper temperature, it is necessary (sometimes) to cut down a lot on the flow - which you should not have to do in warm weather.

The volume control is operating normally, so it must be something on the heating side. Is it the heater or the thermostat is faulty ? Can they be replaced ? Or are these showers worth fixing or are they just throwaway, like a lot of appliances these days?

If you can shed any light on the problem, thank you.

Bruthal

Poulgorm wrote: »

I have a Triton T90xr instantaneous shower (integral pump). It 18 months old and for the last few weeks, it has become erratic. Basically, the temperature control seems to be faulty: on full flow it can get too hot: then it goes cold or just lukewarm: to get a proper temperature, it is necessary (sometimes) to cut down a lot on the flow - which you should not have to do in warm weather.

The volume control is operating normally, so it must be something on the heating side. Is it the heater or the thermostat is faulty ? Can they be replaced ? Or are these showers worth fixing or are they just throwaway, like a lot of appliances these days?

If you can shed any light on the problem, thank you.

The only real way an electric shower can get too hot, is when the water flow is reduced or restricted, or it is already very warm in the storage tank, which can happen on very hot sunny days. But the main ways this happens is when the filter is clogged, the shower head is partially blocked with limescale, or the heating tank in the shower unit is clogged with limescale. Air locks can also reduce water flow, but this would have the water almost stopped.

The result of the above items is, too small a volume of water flows over the elements, it gets too hot, the overheat stat cuts the power to the elements, then they cool, and the overheat stat resets, so the water getting too hot, then cold, will cycle if the shower is left running, if this reduced flow is causing the problem.

So the first things to look at is the filter for debris, and shower head for limescale. The shower head can be left in clear vinegar overnight to ensure it is clear of scale.

Poulgorm

Robbie7730, as I said in my post, there is no problem with the flow: I have checked the filter and the shower head is descaled.

The problem is that the heating is erratic: with a constant flow of water, the temperature varies: sometimes too cold and other times too hot (but not scalding). The flow is steady.

Bruthal

Poulgorm wrote: »

Robbie7730, as I said in my post, there is no problem with the flow: I have checked the filter and the shower head is descaled.

The problem is that the heating is erratic: with a constant flow of water, the temperature varies: sometimes too cold and other times too hot (but not scalding). The flow is steady.

Ok, for the temperature to vary, either the elements have a bad connection, or the flow is varying. Subtle variations in flow would not be easy to see, but will vary the temperature.

Also, if the shower is at full flow, which is the temperature dial at the coldest setting, and is too hot, that is either the attic tank water is very warm which can happen on hot sunny days, or the flow is lower than it should be with the temperature dial at the coldest setting. The dial would still vary the flow rate in this scenario, but at max, the flow would be less than what it should be, but would still seem to be working fine. The elements put a fixed amount of heat into the water, this does not vary (for each element setting selected).

If the element heating circuit has an intermittent bad connection or faulty stat, pressure switch etc, then the shower would go cold, then back up to temperature. It would`t get too hot once the water was still flowing, and it was at a comfortable temperature before the element goes off.

So overall, limescale in the heating tank is a good possibility, if the elements dont have a bad connection. One of those energy monitors would be handy to see if the elements are staying on.

You could do a litres per minute flow test if you have a bucket with a known volume, which would tell us what the full flow rate is at present.

Also, try the shower with the element selector switch on half heat, and set the flow rate/temperature setting, and see how that works.

Poulgorm

Robbie7730, your suggestion that it might be a bad connection was correct: the incoming neutral was barely making a connection - I pulled it out with my fingers: tightened it up and all seems to be well again.

Thanks for your helpful replies.