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Been in our house 2 yrs and the oil burner is approx 12yrs old
Every 6 months or so I have needed to add more water to the system to keep pressure above 1 bar
Did this a couple of weeks back, raising it to 1.5 bar.
However since then it has risen to just below 3 bar causing the release valve to operate.
I’ve bled water from a radiator reducing it down to 1.5 bar but it then again rises back to 3 bar!
It’s done this twice now. No heating on, just the boiler heating the hot water 2 x per day.
What could be going on, do I need to get an engineer?
It’s a Firebird boiler if that makes any odds
Thanks
Expansion vessel got pressure in ?
But it does sound like you have pressure bypass somewhere in the circuit
Fire bird - system boiler heating a tank not a combo????? But then having it pressured doesn’t add up but for completeness.
We had a fire bird boiler was good but our valves kept sticking had to manually manipulate them. Similar age to yours I believe
Expansion vessel got pressure in ?
My Google searching did bring that up, but what pressure should it be, and can I check it using a track pump ?
Yeah track pump fine
Just check pressure with system pressure at 0
If water comes out when you depress the valve it probably banjod
Do you disconnect your filling loop after topping up? If not, any chance the valve is passing?
Do you disconnect your filling loop after topping up?
No it’s a loop, just a valve/tap thing. No sound of water passing the valve
I’ll have a look at the vessel tomorrow
Pressure going down = leak somewhere, water out.
Pressure going up = fill loop leaking or pump manifold/valve stuck open letting water back in.
If your expansion vessel is goosed then that normally (ime) would show up as not holding pressure.
Could be a failed heat exchanger - try physically disconnecting the filling loop and see if it still does it.
It’s probably not the expansion vessel (although that will probably have failed anyway) No CH means not much need for the EV. If it’s goosed, you get excessive pressure rise / blow off when the CH is hot.
It’s a Firebird boiler if that makes any odds
Ours is a disaster - I’ve nursed if for over 15 years, replacing most of it except the actual burner and fire chamber over that time. Next time it’ll be a Grant!
If your expansion vessel is goosed then that normally (ime) would show up as not holding pressure.
Only till you topped it up about 1.5l and the ev was full. (Which it sounds like he's been doing)
The ev for being free to check would be my first check before going nuclear and heading for the heat exchanger. Bearing in mind some boilers heat dump into the heating circuit once the waters up to temp. -but still sounds like is on a system boiler due to his hot water coming on twice a day. If he's a sealed system and the hot water comes on and the valves stuck and the ev is not working....this will happen. We had a Firebird boiler on a vented system and every summer when we wanted hot water no heat we had to manually jam the valve into open.
As for the filling loop -should be double isolated and disconnected just to meet regs so hadn't even considered that.
Replaced our Firebird with a grant tillydog and never looked back
I get that, it'll rise when the water gets hot (either CH kicking in or possibly HW if the pump diverts to heating once up to temp), but it should go back down again when it cools.
EV should be an easy check though, if its at the front of the boiler and easily accessible, when its cold lift it up and check if it sloshes about! if there is excess water in there its probably knackered!
If it's an unvented system then you may have a leak from the hot water in the water cylinder into the heating loop - iirc the water supply should be around 3 bar. As a quick way to check this I'd isolate the water supply to the cylinder and turn off the boiler, latch the DHW zone valve to open position then run a hot tap for a while. If the boiler pressure comes down there's your answer - may take a while as the leak could be a tiny pinhole.
I have no technical advice other than firebird are absolute shite. Ours was a piece of crap from new and replaced with a Grant which has been much better.