Leak from/around boiler pressure regulator (Italy)

[Ric2013]

Had my father's boiler serviced yesterday. (ITALY)

After the service, I noticed a slight smell of gas around the regulator in the boiler (boiler cover is a hinged door, so easy access). Think this was a pre-existing fault. Not a big leak, and would probably pass a gas leak test, though they don't seem to do one over here

I think I've found the best gas installer available locally to carry out the service (and, being in the sticks, it's a local installer or no one at all: no other options as no one will drive 30 miles to service a boiler). He couldn't smell the gas. Hoped he'd have an electronic gas leak detector, but he had a lighter instead. No gas leak detector spray, he had degreaser instead. He's good, but that's how they work here.

The large screw over the regulator had been massively over-tightened, but he said not likely to be the source as this is more a dust cap than a gas seal. Can anyone comment on this observation?

 

[ShaunCorbs]

plastic cap ric ? They do tend to leak from the upso if it’s lpg ?

 

[Ric2013]

It's propanated air! Very few places use it and very few boilers are (genuinely) designed to run off it, or so I am told. So a kind of LPG.

Nah. Ita a metal cap. The smell is still there, but I think it's only when the boiler is firing (or when it has just started firing?). "Cosmogas" boiler. Lump of junk to be fair.

Two photos - one is a close-up, showing the screw. He couldn't actually get it undone and said he'd need a bigger screwdriver, but then decided it wasn't worth undoing anyway!

 

[Gasmk1]

That is the governor you remove that to alter gas pressure doubt if leaking there. There should be a weep hole for the governor possibly on the side of the block to the left. Check with soapy solution if you don’t have leak detector. Make sure you clean off though as it can corrode the alloy over time. The weep is sometimes in the screw cap. It’s there to allow the diaphragm to be able to move up and down and should only be air on that side unless diaphragm is leakino.

 

[Ric2013]

Hi. I've tried a soap bubble on the weep hole. On the left, as you say.

While you can see the soap bubble wobbling slightly, there is no constant growing of the bubble that would suggest a leak.

How airtight are the cork gaskets used in the manufacture of this kind of block? Perhaps I've just got a really good sense of smell, and I'm picking up on an infinitesimally small amount of let-by?

 

[Chuck]

Perhaps I've just got a really good sense of smell, and I'm picking up on an infinitesimally small amount of let-by?

IMO, if you can smell it there's somerthing not right. I think that the fact that you only get the smell at start up may be significant. Is the flue okay? Have you got a CO monitor in the room? If not, you probably want to get one...

 

[Ric2013]

CO monitor is installed (although I've never seen it read above 000ppm even when I took it into the lounge and the woodburning stove was smoking).

Flue is fine as far as I can tell, and I don't think the smell is coming from there. The Italians won't allow a balanced flue as we have them, so inlet comes from outside and exhaust goes up a rigid SS chimney.

I'm not sure about the start-up. It's hard to tell because the boiler cycles a lot during CH and, being a mini-thermal-store boiler which heats through in less than 5 minutes, you don't get the extended firing you would have if there were a cylinder involved. I'll try to check next time I run a bath - see if I can force it to run for an extended period without cycling.

 

[Ric2013]

FOUND THE LEAK!

Yesterday I was rummaging around in the local co-operative's ironmongery department and I came across a can of non-corrosive purpose-made gas leak detector spray for €3,00 (why didn't the local gas guy buy a can?). I allowed myself to use us it a bit more liberally than I had with washing up liquid. The leak appears to be coming from a plastic button thing what looks like (but probably isn't) a screw head cover to the side of the valve.

And, yes, it only leaks when the valve first opens. Actually it seems to suck in when the valve closes and I cannot prove that this is gas that is leaking out, but it would appear to be. Does this seem possible? I don't know what I am looking at, I'm afraid.

I'm put a video up - seems to work in Chrome, but not Firefox. Perhaps it will work for you?

SAM_6085.AVI

Gas leaks when gas valve opens during boiler firing sequence.

www.plumbersforums.net

And here's the item identified on my previous photo:

 

[ShaunCorbs]

Guess it’s a breather port and the diaphragm is split so time for a new gas valve I’m afraid

 

[Ric2013]

Excellent. I'll get Dennis the gas guy to come and mend it then.