Electric Shower Temperature Problems

HLMec413

We are having temperature issues with our Triton T80 (cold mains water fed) Electric Shower. It is less than a year old but for the past few weeks it has been very temperamental.
- The heating element will only come on when the dial is set to the absolute hottest setting at which point it becomes scalding - and it doesn't always turn on so we just get very cold water.
- If we're lucky and time it right, once the element starts working we can adjust the dial downwards to a normal temperature; if we adjust it too quickly, the element turns off and the water turns freezing so we have to turn it back to the hottest setting to get the element to start again and repeat the process.
- If we do it too slowly the thermostat cuts out and there is no hot water left until it has reset.
- When we do manage to balance the temperature, if we move the handheld shower head, the heating element cuts out again.

Does anyone have any suggestions as to what to do? Our mains pressure is okay but on the lower side particularly at peak times.
Thank you in advance!

grumbler

I think, the problem indeed can be with the pressure. When you turn the dial to higher temperature, the flow drops and the pressure rises slightly.

If so, either the pressure is too low or the pressure sensor is faulty.

The warranty is for 2 years, but if it's the pressure that is at  fault, the warranty doesn't help. According to the specifications the pressure has to be 1.0 bar at 8 litres per minute. You can try measuring it in the 'cold water' mode (adjust the flow by rotating the temperature dial).

FreeBear

If it anything like my Triton shower, there will be a little warning light to indicate if water pressure is too low. If the light is not on, then give who ever did the supply/installation a call and get it repaired under warranty - If you purchased the shower yourself, then you will probably need to deal with Triton directly.

Bendy_House

I suspect it's a lack of pressure, as Grumb suggests.

These leccy showers have fixed-rate heating elements in them, which is either 'on' or 'off'. To adjust the temp, what you are doing is adjusting the flow of water across the element - a lesser flow = hotter water temp.

They need a minimum pressure with which to operate, and have a built-in pressure sensor to ensure this min is met. This is usually a crude 'lever' which acts on a microswitch; when the pressure is solid, it pushes the lever, trips the 'switch and all is ok. When the pressure is poor, the lever doesn't move far enough, and the switch is not operated = no element.

What you describe sounds typical of a low mains pressure/flow situation. When you have the shower unit turned towards 'cold', the flow tap inside the shower is opened more fully, so the mains water passes through without being held back. This equals 'low' pressure in the sensor inside the shower, which also means there ain't enough pressure to operate the switch. So, no heat.

As you turn the temp control towards 'hot', you are effectively restricting the water flow through the shower, so the pressure before this sensor increases =  shower comes on.

These are your symptoms. So it's either a case of your mains pressure and low simply ain't good enough in the first place, or - hopefully - the wee filter inside the shower has debris in it, which is restricting the flow.

For the former, you are stuffed*, for the latter it's easy to sort.

* At least it's more tricky.