hot radiator

[gina32]

my heating is switched off and the thermostat on individual radiators are off, so does anyone know why some of them are still getting hot? thanks

[alavahalf]

If theres any or debris trundling round your system. this can cause the TRV's from closing even though you have physically turned them off...there is only a very small hole in the TRV to allow the water through, this can easily become blocked.
A faulty zone valve would allow the radiators to come on..even when you have switched it off at control unit.
That coupled with the TRV's being stuck open, may allow the radiators to come on.
A system flush after applying a cleaning agent may solve it.

I expect this has just started, now that your heating is not operating as often as it did, a few months ago.
You would'nt have been aware of it while the heating was on,
At least it's got you through winter...time for some summer maintenance.

[gina32]

it had a service 2 months ago and it was ok, no debris in the rads!

[alavahalf]

Think the guy who did the service is the next port of call..?

[gina32]

what do you mean?
the heating system is serviced every year, bled them and no gung, just clear water came out

[chas2008]

TRVs can stick, its a very common problem although they usually stick shut rather than open.

[gucciman]

ive never heard of the rads being serviced, only the boiler, and you cant say that there is no sludge in the radiator because the sludge is heavy and settles at the bottom of the rads whereas the bleed vents are at the top of the radiator.

what type of heating system do you have gina? is it a combi boiler or is it a conventional system with a hot water cylinder and tanks in the loft somewhere?

are the rads getting warm only while you are heating your hot water?

[gina32]

no mess, only clear water was coming out when they were bled

[north star]

is it the bathroom radiator that is 'hot'. My bathroom radiator is connected such that if the 'heating' is off but the 'hot water' is on then this radiator gets hot. (if the valve is open).

[vivianmsh]

Some 'older' systems still have a hot water radiator (works off the hot water rather than the heating side) so that you can dry your towls in the summer.

However, if all of your rads are getting hot get your 3-port valve check as this can control you hot water and your heating and it may be sticking.

If it is not the valve check programmer/timer ('Danfoss' is the most common fitted), as they can muck up sometimes.

Lastly, if any work has been carried out recently (or before you owned the house) check the system isn't back flowing and heating the rads from the non-thermostat end (speaking from experience after 3 3-port valve, 2 timers and most of the floors ripped up in my house and the owners finally believing me it was back flowing!!!)

Hope this helps