heating comes with water even with heating turned off

[bazander]

So I have have not had any heating or hot water turned on for at lest 2 months, but yesterday I required some hot water. about half an hour after turning the hot water on, my radiators were boiling hot also.
The controls indicated that the heating was turned off, and the heating control was not touched at all.
Once I noticed the radiators were hot, I even checked the thermostat, and according to the house thermostat, the house was warm enough not to require the heating.
Thus 2 sets of heating controls say the heating shoudl not be on.

Is this a problem with my boiler?
controls?
sticking valve in boiler?
sticking valve elsewhere in house?

Thanks in advance.
Bazander

 

[JCplumb]

Sounds like you have a zone valve not doing its job. I have exactly the same problem in my house, I'll get round to sorting it one day

 

[leesparkykent]

dodgy valve or dodgy cylinder thermostat if its a Y-plan.