Banjo
Fuelled with Jelly Babies
- Location
- South Wales
Sounds like the pressure relief valve is dripping.Eventually boiler will stop due to low pressure.suggest get it fixed asap.
Central heating problem
- Thread starter glasgowcyclist
- Start date
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Bazzer
Setting the controls for the heart of the sun.
- Location
- On the edge of reality
Is it a combi or condensing boiler as I believe both have condensate pipes?
Assuming it's a combi, our combi runs between 1 and 1.5. Running to 2.5 I suspect may test some of the joints and valves. We had a problem where the gauge was showing a wide range of pressure from cold to hot and the boiler was discharging excessively when hot. When cold the water was topped up, that merely repeated the cycle. That was traced to an air leak. Once that was fixed and the boiler recharged, no more wide range of readings.
Assuming it's a combi, our combi runs between 1 and 1.5. Running to 2.5 I suspect may test some of the joints and valves. We had a problem where the gauge was showing a wide range of pressure from cold to hot and the boiler was discharging excessively when hot. When cold the water was topped up, that merely repeated the cycle. That was traced to an air leak. Once that was fixed and the boiler recharged, no more wide range of readings.
Globalti
Legendary Member
As Tim Hall writes above, the condensate drain is supposed to drip water. You can prevent it from freezing by:
1 - Re-routing it so that it runs entirely indoors and drains into a sink drain, for example.
2 - Fitting a boiler condensate trap, which will hold back the condensate then release it in a rush, preventing freezing.
We had a graphic illustration of the problem one winter in Aviemore when it hit minus 24c and the hotel staff asked us not to allow water to trickle down the drain but to fill the sink or bath then allow it to pour out in a rush, to prevent it from freezing in the outdoor drain pipes.
1 - Re-routing it so that it runs entirely indoors and drains into a sink drain, for example.
2 - Fitting a boiler condensate trap, which will hold back the condensate then release it in a rush, preventing freezing.
We had a graphic illustration of the problem one winter in Aviemore when it hit minus 24c and the hotel staff asked us not to allow water to trickle down the drain but to fill the sink or bath then allow it to pour out in a rush, to prevent it from freezing in the outdoor drain pipes.
glasgowcyclist
Charming but somewhat feckless
- Location
- Scotland
To clear up any confusion by me possibly using the wrong term for it, here's a picture of the pipe from the inside where it passes through the wall from the boiler. What is it?
Levo-Lon
Guru
If it's the PRV then you would either have a boiler that wont run due to low pressure..and the gague will read 0 or maybe .5 bar.
I can't see your filling loop either which you have with a combi.
So I'm thinking it's a tank fill and a condenser.
As it froze and then worked fine after removing Ice.
Check for a pressure gague if you think it's a combi..it will read around 1bar + cold.
It will run at .5 .
If the PRV is at fault that pipe will vent hot water as the heating gets hot.
It would normally then stop working as your pressure drops below working pressure..which will be .5 to 3 bar.
PRV valves blow at 3 bar as a rule to save burst pipes
I can't see your filling loop either which you have with a combi.
So I'm thinking it's a tank fill and a condenser.
As it froze and then worked fine after removing Ice.
Check for a pressure gague if you think it's a combi..it will read around 1bar + cold.
It will run at .5 .
If the PRV is at fault that pipe will vent hot water as the heating gets hot.
It would normally then stop working as your pressure drops below working pressure..which will be .5 to 3 bar.
PRV valves blow at 3 bar as a rule to save burst pipes
Last edited:
U
User6179
Guest
PRV, If its working correctly then it is releasing water because the pressure is too high, I don't know myself what that pressure is but I would guess around the 3 bar mark.
U
User6179
Guest
I think its the Flexi pipe, you can see it connecting on the left side of the pic.
Only just noticed your post ^ I don't know with these modern condensing boilers, maybe it's some sort of dual valve then installed along with the prv to work for both occasions now days?. That would account for the boiler working after he unfroze it.
lazybloke
Ginger biscuits and cheddar
- Location
- Leafy Surrey
The expansion vessel in my boiler failed last year. Not initially obvious because the gas was now in the pipes and still providing space for expansion... until I bled the rads! Came home that evening to a cold house, a puddle on the patio, and zero bar of pressure in the boiler heating system.
If you're not sure whether this is a condensate or pressure release pipe, download the boiler installation manual - this should give you some clues.
If you're not sure whether this is a condensate or pressure release pipe, download the boiler installation manual - this should give you some clues.
cyberknight
As long as I breathe, I attack.
- Location
- Land of confusion
Used to warm my hands up as a milkman on boiler outlets mid winter
U
User6179
Guest
I don't know how it works but when I got the new boiler fitted I thought it was knackered because it kept gurgling every few hours, turned out it was just releasing the condensed water into the outlet.
tony111
Veteran
Sounds like the expansion vessel has lost it's charge. If you locate the Schrader valve on the expansion vessel and press the valve spindle in, you should get a puff of air,If you get water...not good, you need a new vessel. If you get air, it probably needs a bit more air pumping in with a bike pump. Google it...there's a few you tube videos on there. Good luck.
