Hot water - too hot!

misterthrifty

Since moving to my new house I have found the hot water to be much too hot. The water is heated in an immersion tank from the central heating boiler. I have tried turning down the thermostat strapped to the immersion heater, currently 50 deg, but it seems to make no difference.

It may seem like a foolish question, but is the thermostat likely to be faulty or is there another likely explanation? The thermostat is wired to a connection box and, I assume, can be swapped fairly easily but I would rather check than waste my money.

Any advice appreciated.

weekendwarrior

It sounds like you have a cylinder like this-

http://www.ultimatehandyman.co.uk/plumb_immersion_heater.htm

That is combined, adjusting the thermostat on the cylinder will only reduce the temperature if you are using the immersion heater! The immersion heater only works when you switch on the immersion heater switch.

You are using the boliler to heat the water in the cylinder and so this is where you need to adjust the temp of the water. This may be on the boiler itself or is sometimes below the flap on the gas fire ( if you have a back boiler )

djohn2002uk

I have to say that the above post is totally wrong.
If you have a thermostat strapped to the cylinder with an electrical lead going to a junction box then it IS to control the hot water side of the heating system. I would turn it gently in both directions with your ear close to it and see if you can hear it click. If you can't then it does sound as if it's faulty. If it does click then it is working and I would try turning it down a bit lower incase it isn't very accurate. Make sure it is fitting tight against bare copper on the tank too so that it senses the temperature inside properly.

moonrakerz

It might be worth checking that you don't have an electric immersion heater that is switched on too !

weekendwarrior

djohn2002uk wrote:

I have to say that the above post is totally wrong.
If you have a thermostat strapped to the cylinder with an electrical lead going to a junction box then it IS to control the hot water side of the heating system. I would turn it gently in both directions with your ear close to it and see if you can hear it click. If you can't then it does sound as if it's faulty. If it does click then it is working and I would try turning it down a bit lower incase it isn't very accurate. Make sure it is fitting tight against bare copper on the tank too so that it senses the temperature inside properly.

Sorry,

Read it quick and missed the "strapped" bit.

DOH

Weymouth_Man

Sounds to me thats it's a faulty thermostat, as in this link.
9 Down Cylinder Thermostat.
http://www.toolstation.com/search.html?searchstr=thermostats
But also good advice by me MSE colleague to check if the electric immersion heater is switched on, which of course will over ride the central heating system, not to mention the additional cost. :eek:

misterthrifty

Thanks all, that helps a lot. I had already checked the immersion was off and is controlled by a large 'economy 7' box.

The thermostat temp setting is difficult to turn as the screw is plastic and rounded off but I could not make out a click.

The link to a replacement is handy as I couldn't see one in Screwfix whom I would usually use.

Looks like a job for next weekend. Cheers.