HOT WATER WONT TURN OFF

[Ryan Carr]

Hi,
so basically my hot water won’t turn off...
I don’t have a combi boiler, I have a big hot water cylinder at the top of the house etc.. the thermostat on/off control unit controls the hot water and heating etc.... this system has been fine for over 20 years but all of a sudden, even though we can switch the controls off, and it says off.... the hot water is still going and heating up to maximum temperature, despite the boiler being turned down to minimum and the thermostat in minimum and the hot water actually being turned off!!?
The boiler is constantly kicking in and heating the water up.

Any help or advice Is MASSIVELY appreciated if possible...

 

[SJB060685]

Motorised valve seized open and keeping the end switch contacted if S plan system?
Someone with a multimeter can diagnose

 

[centralheatking]

Hi,
so basically my hot water won’t turn off...
I don’t have a combi boiler, I have a big hot water cylinder at the top of the house etc.. the thermostat on/off control unit controls the hot water and heating etc.. this system has been fine for over 20 years but all of a sudden, even though we can switch the controls off, and it says off.. the hot water is still going and heating up to maximum temperature, despite the boiler being turned down to minimum and the thermostat in minimum and the hot water actually being turned off!!?
The boiler is constantly kicking in and heating the water up.

Any help or advice Is MASSIVELY appreciated if possible...

Turn heating off till you get professional help you don’t want to kettle the cylinder. If you do use the heating small bursts only. If you have an immersion use that a bit for hot water centralheatking

 

[king of pipes]

As above first thing to check is the motorised valve or valves you could have a back feed from somewhere or the micro switch in there is not making when satisfied. Kop

 

[gmartine]

I'll take a punt and say when someone declares it's been alright for twenty years and you end up asking for help here, it hasn't been serviced or looked at professionally in that time.

Youv'e been very lucky then, contact your local GSR.