Leaking central heating system

[Berwick]

We have a leak in a pressurised c.h. system which runs off a combi boiler. We've checked all the visible parts of the system such as radiator valves, etc., and looked for stains on ceilings but found nothing. So, we assume the leak is occuring underneath the floorboards. Having read in previous postings about Fernox sealant we would like to try this before lifting floorboards, etc. Can anyone tell us how to get the sealant into the system. Thanks in advance.

 

[turnpin]

I see in your post that you have checked for visible signs of leak I wondered if you have checked outside your property to see if your prv [pressure relief valve]
has operated and may still be letting by you can find info re leak sealer on fernox website regards turnpin

 

[shneld]

as turpin said.

We were loosing pressure all the time on our CH system.

Checked outside and the PRV had been relieving (faulty)

 

[Berwick]

Thanks for swift reply - have been onto Fernox website and found information re application of sealant. Re PRV - the boiler is located in an upstairs box room - will the overflow pipe for the PRV come out of the wall close to the exhaust flue? I'm having to ask this because the boiler in question is 100 miles away at an elderly relatives so I'll be seeing the system for the first time at the week-end. If the PRV is leaking I assume we'll have to get a plumber to replace it? Regards

 

[turnpin]

pipe will be at least a couple of feet below flue you will need to get a qualifed person in if this is what it turns out to be I wonder if you have another relativ e/neighbour who can send you a picture from a camera phone regards turnpin

 

[newbie1]

really need an engineer to start checking things out as prv is classed as a safety device even under boards you wld have noticed a leak by now

 

[Toddyplumb]

If it isnt PRV. Take all plastic caps off lockshields and rad valves(if fitted) put tissue paper round gland leave heating off overnight check tissues before heating comes on . A favorite leak spot for a slow leak !