Boiler losing pressure when not on

Joined
2 Dec 2005
Messages
57
Reaction score
0
Country
United Kingdom
Hi

I have a Heatline C24 boiler, Temp would rise into the red when heating on and lose all pressure through the night..Expansion vessel had gone, So recently fitted an external expansion vessel which solved the temp riseing problem but still seems to lose pressure over night. Guessing theres a leak somewhere..95% of my pipework is visable and all rads seem fine ( no obvious leaks )..could the PRV be losing the pressure??Any advice would be appreciated
 
Sponsored Links
Tie a plastic bag over discharge pipe and see if it collects water. Fitting a new EV has nothing to do with controlling temperature. That is done within the boiler by sensors, pcb and gas valve. Temp rising into the red? Don't you mean pressure rising? All very confusing when you use the wrong terminology.
 
Yes sorry..I did mean Pressure rises into the red, then loses all pressure..Sorry...I will tie a bag onto the pipe and see.Thanks
 
Hi

I have a Heatline C24 boiler, Temp would rise into the red when heating on and lose all pressure through the night..Expansion vessel had gone, So recently fitted an external expansion vessel which solved the temp riseing problem but still seems to lose pressure over night. Guessing theres a leak somewhere..95% of my pipework is visable and all rads seem fine ( no obvious leaks )..could the PRV be losing the pressure??Any advice would be appreciated

OK here's my experience with Heatline C24 losing pressure. The 1st time was while the boiler was still in warranty, the gas engineer wanted to fit an external replacement expansion vessel which was ugly and would have been visible in a small kitchen, so I refused and insisted that the original was replaced, this didn't go down to well as the whole boiler would have to come out to access the old one. The young inexperienced engineer called another older engineer out, this guy knew exactly what the problem was. He removed the braided flexible pipe that goes to the bottom of the expansion vessel, this was blocked solid with black crud, he poked it out and rinsed it out over the sink. Once replaced and with the water pressure primed using the filing loop, the problem was cured. He advised me to have the system power flushed to prevent the problem again. The cost of power flushing being circa £450 I decided to use FERNOX chemical clean and do it myself. I chemically cleaned the system again the following year and had no more problems for 5 years. This year the same problem occured, so I drained the system, removed and cleaned the pipe, re-filled with chemical cleaner and ran the system for 24 hours, then drain/flush with clean water, then refilled with FERNOX inhibitor. All time consuming but saved me a fortune. So I'd say the Heatline is a good budget boiler but keeping the system clean is the key to a longlife.
 
Sponsored Links
We would like to believe he means pressure when he says temperature, otherwise could he mean "temperature sensor" when he says "expansion vessel"?
Joking aside, with the expansion vessel replaced (and correctly charged) and pressure still dropping, water is being lost from the heating circuit somewhere. As pointed out by 45yearsagasman in the previous post, the safety relief may be passing water through the discharge pipe to outside - for RGIs it's a common failure following the expansion vessel problem.
@ trickytrev: you didn't answer his subsequent pressure loss question, and fortunately this model of boiler doesn't require removal of a hermetic cover to access the expansion vessel flexible. Be careful what you write.
 
We would like to believe he means pressure when he says temperature, otherwise could he mean "temperature sensor" when he says "expansion vessel"?
Joking aside, with the expansion vessel replaced (and correctly charged) and pressure still dropping, water is being lost from the heating circuit somewhere. As pointed out by 45yearsagasman in the previous post, the safety relief may be passing water through the discharge pipe to outside - for RGIs it's a common failure following the expansion vessel problem.
@ trickytrev: you didn't answer his subsequent pressure loss question, and fortunately this model of boiler doesn't require removal of a hermetic cover to access the expansion vessel flexible. Be careful what you write.

Ha I see why you call yourself Bolshy, going around telling people to be careful what they write, well thanks for the advise but I'll pass on that.

For people who wish to learn from other peoples experience please accept my apologies, all my previous post was true and accurate in all but one error, my boiler is the S24 not C24 as claimed, as my boiler doesn't have the model number on it I made a genuine mistake having Googled a question about the S24 Heatline losing pressure, threads came up about the C24 which I assume to be my model - So if you have a loss of pressure on a S24 and are struggling to get a fix - you may wish to look at the braided hose for blockage - or get some one like a reputable plumber to look for you and mention it to them. No doubt Bolshy will check my spelling/grammar and issue warnings accordingly - great to know he's watching over.
 
The reason I can comment on your post, is I'm registered to work on gas boilers. And this is a forum. And we all have to be careful about the advice we give.
Clearly you don't need any advice, as far as you're concerned the pressure problem you describe is the only type ever experienced on this model of boiler....... :eek:
We are trying to help the Op.
 
The reason I can comment on your post, is I'm registered to work on gas boilers. And this is a forum. And we all have to be careful about the advice we give.
Clearly you don't need any advice, as far as you're concerned the pressure problem you describe is the only type ever experienced on this model of boiler....... :eek:
We are trying to help the Op.

I never said you couldn't comment on my post, however instead of warning people to be careful you could have asked for clarity, that's what polite people do! As for my experience on the S24 having happened twice and being the only problem to date, anyone knows that when something goes wrong on a particular design then the problem is likely to repeat on them all. I took the time to pass on my experience out of being good natured and also knowing that 'so called experts' don't know everything, if I'd allowed the 1st 'registered gas fitter' to repair the boiler his way, I'd now have an ugly after-market expansion vessel stuck on the wall. My advise is (a you say) only specific to one problem, but it's exact in detail and not conjecture between so called experts who suggest changing endless components at great expense with no guarantee of the problem being fixed, my advise is free, the fix is free, and if it doesn't work you've lost nothing!
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top