Gas smell from boiler after switching off CH

[Harry Bloomfield]

Engineer popped over today, did some checks and confirmed the gas valve was faulty.

Has the gas valve been replaced, hopefully?

It's been a few hours since he left and happy to confirm the pressure gauge is now stable, no longer increasing whilst the radiators are on however I've noticed the copper pipe outside which I believe is connected to the PRV has a very slight drip, is this normal? If not what would be causing the drip from the outside PRV pipe?

The PRV is designed to only leak, when the pressure exceed what the PRV is set for. If the pressure in your system, remains below 3bar, as it should, even when hot, then it should not be dripping. What sometimes happens, is it opens due to over pressure, some grit gets trapped in the valve, then it continues to drip despite the pressure reducing.

 

[oilhead]

I would monitor this for a day or so, if it continues then call engineer back.

 

[Al@n]

Has the gas valve been replaced, hopefully?



The PRV is designed to only leak, when the pressure exceed what the PRV is set for. If the pressure in your system, remains below 3bar, as it should, even when hot, then it should not be dripping. What sometimes happens, is it opens due to over pressure, some grit gets trapped in the valve, then it continues to drip despite the pressure reducing.

Yep it was replaced no more smell of gas

We have the central heating currently running pressure is showing as 2.2 bar but I can still see the PRV pipe outside dripping very slightly.

Should the drip eventually stop, or should I arrange for the PRV to be replaced or alternatively just live with it!

 

[Stuckinarut]

Yep it was replaced no more smell of gas

That’s good news.

Should the drip eventually stop,

It would depend if it’s reseated and the spring hasn’t weakened.

or should I arrange for the PRV to be replaced or alternatively just live with it!

As per @oilhead monitor it, then get it replaced, certainly don’t live with it if it’s faulty, as you’ll end up topping the pressure up more frequently.

He also noticed the pressure gauge increasing above 3 bar despite lowering the pressure from one of the rads whilst the radiators were on

Prv activates usually at 3 bar, as this is the preset value.

I'm thinking could the engineer have perhaps caused this by pumping the EV too much? Which is now causing the PRV pipe to slightly drip

Wrong. Prv has weakened or nor seated properly

 

[Harry Bloomfield]

Should the drip eventually stop, or should I arrange for the PRV to be replaced or alternatively just live with it!

You will lose pressure, and need to keep topping it up. You might be lucky and find it eventually self seals, just give it a day or two, then call him back.

 

[Al@n]

Thought I was onto a winner, woke up this morning and the pressure guage was reading zero!

We've topped it back up to 1.5, what what be causing the gauge to drop to zero so quickly, the PRV?

I checked the expansion vessel with a pressure gauge, it is still reading at 1 bar

 

[Harry Bloomfield]

We've topped it back up to 1.5, what what be causing the gauge to drop to zero so quickly, the PRV?

Probably, you don't need to lose much water, to have the pressure dive.

 

[Al@n]

I'll check tomorrow morning, if it drops again I'll call the engineer to replace it.

I'm going to order it now to be safe, I can see two types brass and plastic, does it need to be like for like replacement or will either do?

 

[Harry Bloomfield]

I'll check tomorrow morning, if it drops again I'll call the engineer to replace it.

If you let the engineer know, the PRV is passing, just ask him to ensure he has one on his van, to replace it with. If he supplies and fits, and it still leaks, he should fix it free. If you buy your choice of part, and it fails, he can charge you for a visit.

 

[gas112]

prob get away with just splitting it and cleaning the seat

 

[Al@n]

So the PRV was replaced today the copper prv discharge pipe was full of crud! Engineer cleaned it as best as he could.

So far all appears to be fine, although I can still see a slight drip on the PRV pipe outside, hoping it's just residual water!

 

[dilalio]

So far all appears to be fine, although I can still see a slight drip on the PRV pipe outside, hoping it's just residual water!

Depends how long it is.
Sure it's not rain/water running outside it?