radiators heating when "water heating "is on

[trescinnia]

I have recently drained my fully pumped vented system and once refilled I ran the boiler to check all was well and the pump etc was circulating .it was . I noticed that the programmer when set to water heat only the radiators got warm as well ! Could this be due to the motised valve not working ? it is a honeywell valve .

 

[ollski]

Did you latch the lever on the valve open when you refilled?, if not need a new ball and plate and possibly actuator.

 

[Alfredo]

Its most likely a 3 port problem as outline above, but also make sure your boiler stat is not on max as you can get radiators heating off the return pipe if you are bashing more heat into the system than the HW cylinder can absorb. The heat has to go somewhere.

Alfredo

 

[ChrisR]

but also make sure your boiler stat is not on max as you can get radiators heating off the return pipe if you are bashing more heat into the system than the HW cylinder can absorb. The heat has to go somewhere.

I think you can safely ignore that.


The fault could be a faulty motorised valve head, a sticking motorised valve body, a worn motorised valve body, faulty thermostat(s), incorrect plumbing, or incorrect wiring. If only one rad (eg bathroom) gets hot, it could be designed that way.
I'd start by checking the wiring because it's often wrong, and it takes me about 3 minutes. First time might take ya an hour though.

 

[Alfredo]

but also make sure your boiler stat is not on max as you can get radiators heating off the return pipe if you are bashing more heat into the system than the HW cylinder can absorb. The heat has to go somewhere.

I think you can safely ignore that.


The fault could be a faulty motorised valve head, a sticking motorised valve body, a worn motorised valve body, faulty thermostat(s), incorrect plumbing, or incorrect wiring. If only one rad (eg bathroom) gets hot, it could be designed that way.
I'd start by checking the wiring because it's often wrong, and it takes me about 3 minutes. First time might take ya an hour though.

As its only a drain and refill, its well worth mentioning checking the boiler stat setting, even though the 3 port is the likely one. I've found people getting hot rads on the return often enough to make it worth a quick visual check..Why not for 20 seconds of your time.......

Alfredo

 

[trescinnia]

i cant understand why the wiring needs checking as it hasnt been changed .