1 PERMANENTLY HOT RAD

[Kennyd]

I have an unvented system using a potterton boiler. Just before x-mas I noticed that the bathroom rad was permanently on. We do have a frost stat in the system but I assume this should not operate continuously. There appears to be no way to adjust the rad, if I turn it too far down the boiler trips out. There are 2 motorised valves in the system one marked with A-B and sliding s/w between them (not for manual op) and a s/w on the side. The other has a s/w at one end of which it says flushing only the other end I cant read. I have just noticed that the CH is coming on at times when it is supposed to be off, and at this moment it is heating the house even thought the thermostat is set to its lowest position.

Any Ideas most welcome

 

[baxpoti]

What boiler are your two motorised valves connected to?
Does the radiator only get hot when the hot water is on?

 

[Donki]

I have just noticed that the CH is coming on at times when it is supposed to be off, and at this moment it is heating the house even thought the thermostat is set to its lowest position.

Is telling me that the CH zone valve is passing & stuck in the on position. Change actuator head and check the spindle in the valve for stiffness, is its stiff try WD40 or just change the full valve, Honeywell are the best you can get...
PS make sure you turn the power off first

 

[wilhelm]

how is the dubs going to free up the ball or plate of the valve, that is caked up with shytte?

 

[Strachan]

Maybe by magic?

 

[Donki]

how is the dubs going to free up the ball or plate of the valve, that is caked up with shytte

yes the ball or the plates inside the valve could be "caked up with shytte" as i said try the WD40 if the spindle is stiff, if it don't work change the valve. The muck inside the valve is another problem that should be addressed.

 

[wilhelm]

...........

ok.........

MOD 2

down boy

 

[KennyDunn]

thanks for the replies guys. Changing the valve cured the C/H prob. However it didnt cure the 1 hot rad prob. Having checked the pipes again I find that the hot water comesfrom the pump, it then can go through either of 2 valves (I assume for hot water or C/H) or through a branch pipe. This pipe appears to be the pipe which goes to the 1 hot rad which is in the bathroom and is permanently hot. I can see nothing in the system which would tun it on or off. Nothing has been changed about the system since its installation some years ago.

 

[doitall]

The radiator is being used as a by-pass circuit for the pump.

 

[MasterAbacus]

Our system does exactly this too...

Our bathroom radiator get hot when hot water is on, and the rads are put on....

After some digging around and asking question, even several local plumbers, i found that it wasnt a stuck valve, it is a system design.

the Rad gets hot at some kind of heat soak, dont ask me why, ive no idea, but that what ive been told.

I assume its something to do with the old coal fired back boiler that was fitted origonally, and was later coverted to oil heating system.

Makes no difference to me, everything works fine, obvs in summer it get a liitle warm in bathroom, but can just turn of the valves to rad.

P.S. i changed it for a Towel rail Rad, looks better, and the towels are always warm...

 

[bster]

It gets hot to dry your towels, if you dont want it on turn off on rad valve -

I think its a good idea.

 

[doitall]

It gets hot to dry your towels, if you dont want it on turn off on rad valve -

I think its a good idea.

It depends on the boiler, if original it would have been designed that way.

It cannot be turned off without damage to the pump and or boiler

 

[bster]

As a newbie I always assume it is a relativly new system and thus omit (unintentionally) from my train of thought that it may be an old system. And in this case i assumed it was a 'convienent' bathroom raditor (mimicking the trad heat leak rad that is essential to the operation and requirement of a certain systems design) rather than the more obvious (because it has no valves) essential heat leak radiator that is indeed essential to the systems operation and intentionally installed to operate as the OP describes.


Still learning

Bster

 

[doitall]

As a newbie I always assume it is a relativly new system and thus omit (unintentionally) from my train of thought that it may be an old system. And in this case i assumed it was a 'convienent' bathroom raditor (mimicking the trad heat leak rad that is essential to the operation and requirement of a certain systems design) rather than the more obvious (because it has no valves) essential heat leak radiator that is indeed essential to the systems operation and intentionally installed to operate as the OP describes.


Still learning

Bster

Impressive

The OPs system is an S plan and requires a by-pass for the pump, if he doesn't want the rad to get hot then an auto by-pass valve would have to be fitted, in addition if all the radiators have thermostatic valves a second avdo would have to be fitted on the heating circuit

 

[KennyDunn]

I am aware of the requirement for a by pass however this rad can not be turned off manually as this results in the boiler turning itself off for safety reasons but the pump is working 24/7 and the rad is always hot thought this hasnt always been the case. I am sure we were told when it was fitted that it would turn on and off throughout the day and night and it has only recently been working 24/7.
Thanks again for your time and effort all replies are very much appreciated