FAO central heating bods

[Matty6]

I’ve got a traditional central heating system (boiler downstairs, hot water tank in the airing cupboard jobbie). It’s old and will be replaced at some point for a combi.

However, recently something weird has been going on. If you turn off the heating using the thermostat downstairs you can hear something in the airing cupboard is still active. Sounds like a pump or valve is still running. If you feel the pipes you can feel that water is still being pumping around. Also, every so often the boiler will still fire up. The rads don’t get warm though. The only way to stop the noise from the airing cupboard is to turn off the power switch in the airing cupboard. It’s damn right annoying! When you’re sat downstairs it sounds like the heating is still.

Anyone know if this sounds like a small issue or something bigger? If it’s the latter I may I just bite the bullet and get a combi fitted.

 

[CliveW]

Switching off the heating by using the room thermostat will only stop the flow to the radiators.The boiler/pump will still supply heat to the hot water cylinder which is what you're hearing.

 

[Matty6]

Strange thing is the noise I’m hearing now hasn’t happened before in the 5 years we’ve lived here. Normally you turn off the thermostat and there is then no noise. Periodically I’ll here a subtle noise which I presume is to do with heating the water in the cylinder.

Now when I turn off the thermostat the sound is exactly the same as when the heating is on.

 

[CliveW]

Perhaps the bearings in the pump are on their way out.

 

[jim8flog]

lIs the hot water pump or gravity fed?

If pump fed with a 3 way valve? Is the valve thermostatically controlled? Ie is there a thermostat on the tank?* Is it the valve not operating leaving permanent hot water demand.

In hot water only mode with a thermostat of the water tank try turning the thermostat on and off and listen for what is happening.

 

[bigslice]

I wud get rid of tge jobbie, must stink

 

[PhilTheFragger]

you might have a frost stat somewhere which is kicking in to prevent the system freezing. Maybe in the loft

we had one go wonky, kept coming on in the middle of summer when the heating was off

 

[palindromicbob]

Something similar happened to me. Was a faulty valve. Plumper fixed it in about 45 minutes after diagnosis going to get the part and coming back to fit.

 

[Deleted member 1740]

I'd be looking for the frost stat firstly, it sounds like its just kicking in and flying round the bypass because the frost stat is sensing low temp. Cost no more than £120ish to fix it.

If you can change a plug your be ok swapping it yourself an save 60ish. If you want any advice send us a PM and I'll talk you through it:thup:

 

[Matty6]

Thanks everyone 👍

Stu, I’ll be in touch mate.