(edit title) Electric Shower query Limescale causing Temp. control issues Options

[John.Smith]

Howdy,
Been googling for a while now and can't seem to get the info I need so said I would put the question out here.

I have a Triton T90si electric shower installed in a house I am renting out back home. The water in the area is very heavy i.e. limescale. The tenant has mentioned that the temp control dial is not controlling the water effectively in that the water is either boiling hot or cold. There is no inbetween.

I replaced that shower 4 years ago due to same issue. However, now I am wondering if I could just replace the affected parts (much cheaper) considering that a new shower will likely only have a similar 4 year lifespan due to the water.
A parts catalog can be found here for the shower. My reckoning is that either one of (or both) parts 3 or 4 need to be replaced (the heating element and thermostat I am guessing).

What do those more clever than I think, considering the limescale issue it is likely that the heating element is clogged up with calcium carbonate and same for the thermal cut out (thermostat?)... wold that explain the behavior?

[mångk]

You could try running a calcium/lime/rust product solution through the system. This may give you a better idea which direction to go.

It sounds possibly like the thermostat is not kicking in when it should and that is possibly why it is either very hot or very cold.

[byke]

My only advice is to make sure you dont replace it with a German shower unit.
Although it may help reduce any complaints from your current tenant.

[John.Smith]

You could try running a calcium/lime/rust product solution through the system. This may give you a better idea which direction to go.It sounds possibly like the thermostat is ... (show full quote)

You could try running a calcium/lime/rust product solution through the system. This may give you a better idea which direction to go.

It sounds possibly like the thermostat is not kicking in when it should and that is possibly why it is either very hot or very cold. ... (hide full quote)

Tried such a solution several years ago... not really worth a damn

it feels more like a thermostat issue as the water is heating up. Although I would be tempted to replace the element as a precaution considering it will have a limited lifespan and all...

[John.Smith]

My only advice is to make sure you dont replace it with a German shower unit.. Although it may help reduce any complaints from your current tenant.

Sorry chief... you lost me there???

[mångk]

The tenant has mentioned that the temp control dial is not controlling the water effectively in that the water is either boiling hot or cold. There is no inbetween.

Thick lime deposits on the bit that measures the water temperature acts as a thermal insulator - much like concrete!

What it sounds like is it is taking too long for the thermostat to determine what the actual temperature of the water is. So when the water is heated it doesn't 'switch off' the heating at the right time because it takes too long to heat up the lime deposit and when the water cools down it doesn't 'switch on' the heater at the right time because it takes too long for the lime deposit to cool down.

That is why there seems to be no inbetween temperature!

If the heating element was stuffed it would be usually either cold or hot and not cycling between the two!

[John.Smith]

Excellent explanation, many thanks

Considering a new heating element is only around £55, I might just splash out anyway as a preventative measure. I could keep the old one in reserve and see if i can figure out how to descale it.

[mångk]

If that is the problem then that way you can descale one whilst the other is in use! Switch elements every 2nd year or between tenants.

It may save buying a new heater every 3 or 4 years.

[skogsbo]

the only other solution I can see is removing the element and sensor, then immerse them in a boil pan of scale remover, same stuff that you can put in kettles, then boil them. etc..

A longer term solution is to fit an in-line scale remover, either on the whole house supply, or just the shower feed. It depends on if you have issues with kettles, washing machines and dish washer etc.. on where you may want to put it.

[entry]

John, the hard water will continue to foul the temp sensor. Switching to municipal water supply or installing a water softener unit might be something to consider.

[John.Smith]

Hi Guys,
Thanks for the advice! yes I know that a descaling unit fitted to the house supply would fix the issue however it would cost me a lot of money. I had it priced a few years ago and just cannot justify the cost right now as the house is on the market.

There is in fact no thermostat on the shower in question (I did a bit more digging last night). It just has three power settings (6.5, 7.5 and 8.5 Kw) and then you adjust the water flow rate on another dial to get the temp that you want. In other words you set the power for the heater and then depending on how fast or slow the water flows through the element determines the output temp.

This means that it is the heating can/element that is the issue as limescale build up will affect its capacity to heat the water and also affect the flow rate of water leaving the can (limescale build up in the outlet pipe from the can). I found a spare can for £50 and will remove the old one and descale and keep as a spare.

I think you guys are right in that it may have to be swapped out every few years unless a household descaler is used.

Thanks as always for the advice

J:S: