Central Heating

[confused2]

At 3am I'm not exactly ready for anything.
EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE
WTF?
EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE
I get out of bed.
It's everywhere.
EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE
Bungalow built on an Indian burial site?
Previous owner returned?
Nah. It's just me and the central heating.
I touch one of the valves.
DONKA DONKA DONKA DONKA DONKA
Gotcha.
I turn the CH off and peace returns.

[Syne]

We use forced-air central heat and air here. So no radiator nonsense.

[confused2]

I don't know whether to call a plumber or an exorcist. Forced air looks like a much more sensible approach.

[Zinjanthropos]

Circulating pump? Could be a bearing. When was last time it saw a drop of oil? On a FA furnace it’s usually a worn fan bearing. Open the wallet.

[confused2]

A Syne indicates - in the UK we tend to have a boiler that heats water that is pumped out to radiators in each room. Each radiator is fitted with a rather crude mechanical thermostatic valve (TRV) that closes off the supply at the room temperature increases. At 3 am all of them must have been just but not quite closed and the springiness in the system set up a resonance (EEEE) - any change altered the resonant frequency (to a much lower DONKA DONKA frequency). The boiler is supposed to have a bypass fitted to stop the pressure rising to the point where resonance can occur but it doesn't seem to be working as intended. Until we have a solution we have to hope it doesn't happen when Mrs C2 is there on her own 'cos it would scare the bejesus out of her.

[Zinjanthropos]

Over ‘ere in Canada a TRV is commonly called a zone valve. Did you bleed any unwanted air from system? Sounds like your boiler may need to be de-limed if that other sound is like low bang or gurgle. Then again you may have a pinhole somewhere that’s acting like a kettle steam whistle. Neoprene hoses reduce vibrational noises.