Help, home heating issue.

Lukelid

Hopefully this is in the right forum, if not I do apologise.

I’m currently having a issue of one radiator upstairs coming on by itself.

My heating is controlled twice,
1st being controlling downstairs and 2nd being controlled for heating upstairs.

Downstairs is set to certain times of the day to come on and upstairs is all turned off. But the one radiator in the bedroom keeps coming on in middle of the night (this radiator does not have a temperature valve next to it either to turn it off) all the other radiators upstairs have a temperature controller by the radiator which I turned to max to see if there getting hot when the bedroom radiator is but there not.

Can someone please help or have any ideas why this is happening?

tim_p

Does the rogue radiator come on when the downstairs ones come on?
Quite possible it’s actually on the downstairs circuit not the upstairs one.
I presume you have a gas boiler and conventional wet system?
You’re saying that just this rad, in the middle of the night comes on?
The boiler must fire up and something must be calling for that heat, a thermostat somewhere.

Gerry1

Has the hot water system has been left permanently on? If so, the boiler will fire up when the water cools down in the middle of the night e.g. a few hours after you've washed up. It's just normal gravity operation, which can be useful if you set the HW to come up shortly before you wake up: the bathroom radiator will take the chill off in the mornings even when the CH is turned off. If the bedroom is more or less above the boiler then some hot water may reach the bedroom radiator, especially if the bathroom valve is turned off.

Blot

It may well be that if the rogue radiator does not have a thermostatic valve it has been designated as the HEAT SINK for the heating system . This is to allow heat in the boiler casing to dissipate when the boiler switches off preventing heat build up and damage in the boiler, the pump will keep running for a short time to allow the boiler to cool. AS previously said the system may have been running to serve the hot water cylinder . Sometimes heated towel rails are the heat sink.