Boiler Saga Continues - Probable Leak...(Update 24/12/20 - Trace and Access visit)

[Gasguru]

You said that when you isolated the downstairs radiators and ran the heating the pressure was ok...and when you opened up the downstairs circuit the pressure dropped. What else can it be but a leak on the downstairs circuit?
Unless you can get the trace and access under your building insurance you will find it very expensive (the equipment is 10s of 1000s to buy), also consider how your future policies will be loaded if they do offer the service.

Intergas boilers are very flexible in the way they can be used and it's a selling point promoted by the importer and that can lead to over complex controls. Given the fact that many installers make a horlicks of the wiring (and don't document fully) it's one reason others avoid them. Most other boiler manufacturers keep things simpler for the UK market so adventurous installers often turn to Intergas. Even the US market get more advanced and flexible Worcester than we do and they're at least 20 years behind Europe in boiler tech.

 

[siross85]

You said that when you isolated the downstairs radiators and ran the heating the pressure was ok...and when you opened up the downstairs circuit the pressure dropped. What else can it be but a leak on the downstairs circuit?
Unless you can get the trace and access under your building insurance you will find it very expensive (the equipment is 10s of 1000s to buy), also consider how your future policies will be loaded if they do offer the service.

Intergas boilers are very flexible in the way they can be used and it's a selling point promoted by the importer and that can lead to over complex controls. Given the fact that many installers make a horlicks of the wiring (and don't document fully) it's one reason others avoid them. Most other boiler manufacturers keep things simpler for the UK market so adventurous installers often turn to Intergas. Even the US market get more advanced and flexible Worcester than we do and they're at least 20 years behind Europe in boiler tech.

That's pretty much the conclusion I came to, the only thing my simple brain can't understand is the fact that the heating still works and can even increase pressure slightly after going to zero? I would have thought a leak would lose pressure continuously and therefore not be able to send water round the system? Or is it the fact that water is being replaced by air?

Also, my insurance doesn't cover trace and access only remedial works to fix damage. I've had a quote of £700 so far, I need to get at least one more. I don't really see another option unfortunately?

 

[CBW]

Intergas are some of the simplest boilers ever made...anyone who has trouble understanding them should be shown the door.
It has a combined PRV and condensate outlet.

I wasn’t aware they have a combined prv/condensate outlet - the one’s we fit I don’t think do.

I don’t understand them much, but won’t be bowing out, just yet, because of your belittling views.

 

[ianmcd]

The British Gas engineer came back and used the leak sealer

Do you have system and boiler cover with BG or just boiler ?

 

[siross85]

Do you have system and boiler cover with BG or just boiler ?

Just boiler unfortunately, it's just the free version that comes with the Gas/Electricty contract.

 

[ianmcd]

There is an old trick that some of us use, pour some cheap aftershave or perfume into the system and sometimes you can smell which room the leak is in

 

[Laurieo]

Hi ,you could hire a thermal imaging camera from about £80 a day .Theirs lots of companies out there ,used them before for tracing UFH leaks .
Good luck .

 

[siross85]

There is an old trick that some of us use, pour some cheap aftershave or perfume into the system and sometimes you can smell which room the leak is in

Wow, does that really work? Might be a slight issue if it's in the open plan room, it's quite a big area.

Hi ,you could hire a thermal imaging camera from about £80 a day .Theirs lots of companies out there ,used them before for tracing UFH leaks .
Good luck .

That's interesting, I didn't think of that. When I spoke to the leak detection specialist, he mentioned that they can be inconsistent sometimes depending on the flooring and the distance to the pipe. I understand the premise of following a pipe showing as a heat line and if there's a "splodge" of heat then there's likely a leak there. Is this a piece of equipment a DIYer could utilise without any prior experience?

 

[ianmcd]

That's interesting, I didn't think of that. When I spoke to the leak detection specialist, he mentioned that they can be inconsistent sometimes depending on the flooring and the distance to the pipe. I understand the premise of following a pipe showing as a heat line and if there's a "splodge" of heat then there's likely a leak there. Is this a piece of equipment a DIYer could utilise without any prior experience?

sometimes works all depends on the depth of the solum and how its insulated

 

[Gasguru]

The system is sealed and AFAIR the Intergas boliers only have a manual air vent on the top.
Bang a hole in the radiator pipework (say a cracked solder joint or nail/screw) and the water will leak out until the pressure in the system equals normal air pressure.
Once that equilibrium is reached no more water will leak out.

Us in the trade (that don't drag the job out) will often have the whole boiler in pieces in the kitchen with the radiators full of water above.
Provided the flow and return rise up into the boiler there is no need to isolate (boiler isolating valves are notorious for leaking when touched) as air pressure will keep the water in the pipework.

If the pressure is zero then as the water is heated it expands and the pressure rises and falls once the system cools.

 

[siross85]

The system is sealed and AFAIR the Intergas boliers only have a manual air vent on the top.
Bang a hole in the radiator pipework (say a cracked solder joint or nail/screw) and the water will leak out until the pressure in the system equals normal air pressure.
Once that equilibrium is reached no more water will leak out.

Us in the trade (that don't drag the job out) will often have the whole boiler in pieces in the kitchen with the radiators full of water above.
Provided the flow and return rise up into the boiler there is no need to isolate (boiler isolating valves are notorious for leaking when touched) as air pressure will keep the water in the pipework.

If the pressure is zero then as the water is heated it expands and the pressure rises and falls once the system cools.

Thanks for that, that's really helpful and informative. I knew there would be an explanation!

I'm now torn between having a go at a thermal camera or letting the professionals have a go. My concern is that a thermal camera is useless without knowledge and experience of what you're looking at.

 

[Gasguru]

Just make sure for your £700 they are willing to drain the system, inject the hydrogen/helium tracer gas and bring out the gas sniffer.

 

[ianmcd]

have a look outside for a drain off cock, they sometimes leak and you wouldnt really notice as it leaks to outside, if you have one it will be lower than floor level and will pop through the wall

 

[Laurieo]

https://www.red-current.com/thermal-imaging-camera-hire/flir-e5-hire

Theres a few videos on here and you can always ring for advice .
I have no connection with this company before anyone jumps in !.

 

[siross85]

Just make sure for your £700 they are willing to drain the system, inject the hydrogen/helium tracer gas and bring out the gas sniffer.

I've spoken to a couple of companies and the £700 quote included trace, access and fixing but I was not convinced with their ability to do the repair, they didn't seem to be full gas engineers, more of a trace and access expert.

The second company is £594 Inc VAT but fixing the issue is extra (£300 Inc VAT). However I got a much better sense of them actually fixing the issue. They will drain the system, inject gas, detect leak, fix leak, retest and provide full documentation. The engineers are fully gas/heating engineers but they actually give you the option to fix yourself if you'd like (I'd only entertain that option if it was extremely easy).

I'm leaning toward the more expensive option, just to get it sorted!

have a look outside for a drain off cock, they sometimes leak and you wouldnt really notice as it leaks to outside, if you have one it will be lower than floor level and will pop through the wall

Can't find anything that resembles a drain off cock outside...

https://www.red-current.com/thermal-imaging-camera-hire/flir-e5-hire

Theres a few videos on here and you can always ring for advice .
I have no connection with this company before anyone jumps in !.

Thanks for that but I feel it would be a wild goose chase for me and I'd rather just get it sorted now.
The only rental places near me is Jewson and they're a bit more expensive.

I've done a little bit more testing too.

- I topped up the boiler to 1.5 bar and then isolated the downstairs heating pipes overnight. Came down at 5am this morning with the heating being on/off multiple times over night and the pressure was perfect, exactly where it was at 1.5 bar.

- This evening I topped up the boiler, bled the rads, topped up again to 1.5bar and made sure the heating wouldn't come on (to replicate pressure dropping scenario). I removed the condensing/prv pipe and put it in a bucket. Came back 90 minutes later and pressure was down to less than 0.5bar and very little water in the bucket, there was some but not much at all, presumably this could simply be latent condensed water in the pipe itself.

So there's no evidence for me to believe it's anything other than a leak in the downstairs heating pipes...