Boiler nearly always hot

MuddyDog

Have a Firebird boiler which is outside in the garage. It's used to heat the rads and our water. We have a water tank in the attic and a hot water tank in the hot press upstairs and we have a Nest installed upstairs inside too. I assumed the micro valve was stuck on but when the boiler is off even if I turn the thermostat on the boiler itself to the max it doesn't come on which makes me think it's not the micro valve being stuck which is the common problem.

Any ideas? The pump attached to the boiler is always very very hot to touch and it makes a bit of a quietish creaking noise too when hot as if the blades are hitting something or similar.

The sunvic motorized valves lights come on when the Nest turns on the heat or boosts the water and the lights go off when the Nest tells it to. Should these lights remain on though if there's an issue with the valve or will the micro valve inside it being stuck open be irrelevant to the light being on or off?

jimf

no the lights will go off but the micro switch could still be stuck

you say valves so I presume you have some kind of zoning maybe upstairs/downstairs/hot water


can you figure out which zone is getting hot when the boiler is hot

if the motorised valves are the same you could change the heads and if the problem moves to another zone you have your culpit

MuddyDog

jimf wrote: »

no the lights will go off but the micro switch could still be stuck

you say valves so I presume you have some kind of zoning maybe upstairs/downstairs/hot water


can you figure out which zone is getting hot when the boiler is hot

if the motorised valves are the same you could change the heads and if the problem moves to another zone you have your culpit

Just one zone.

The circulating pump remains permanently on I've since diagnosed. Only way to get it off is to cut the power to the boiler. When I power it back up the pump kicks in again. Always remains super hot and untouchable actually.

jimf

its really not making since but I would be suspicious that you have a circulation issue going on

super hot pump means its not circulating or else your system is low in water

when you turn up the stat on the boiler and nothing happens the boiler has either reached its max temp on the run stat or else it has tripped the high limit stat

on the stat at the boiler there will be a small little cap to be unscrewed under this will be a little pin button press this and see if the boiler kicks to life

if it does it means you have a circulation problem

once the power to the boiler is on the pump will automatically have power as well

reading your post again the main question is the boiler running or not