Can't find gas leak. Losing will to live

[Riley]

Afternoon chaps

ive spent the last few hours trying to trace a gas leak at a property.

Traced it it back to boiler but cannot find anything at fault with sniffer etc. Have nipped up all joints leading to boiler and inside. It's after the gas valve on the pipework but as its a room sealed unit it must be before the combustion chamber as the smell is noticeable in the room. It's a Worcester Greenstar he plus if anyone knows any traits with these????

any help welcome as I'm losing my rag with it

 

[lame plumber]

have a coffee. turn on the gas and work from the gas valve onwards, it will be there. Ipresume the tightness test is fine to the gas valve, been caught out before with 2 leaks 🙂

 

[Riley]

Absolutely fine up to the butterfly iso valve it has that silly little plastic cap inside the combustion chamber that leads back to the gas valve. Never know if that should be a tight fit or not

 

[Super Mario]

Change gas valve

 

[Riley]

Going to

 

[stevetheplumber]

if its the boiler im thinking of can you dis at point where it goes into the hex and cap or even the top of the gas valve

 

[newcastle phill]

Can you stick your sniffer in the flue.
Turn the gas valve off.
Give it 20 mins test.
Turn gas valve on.
Give it 20 mins.
Compare

 

[quality]

Can you stick your sniffer in the flue.
Turn the gas valve off.
Give it 20 mins test.
Turn gas valve on.
Give it 20 mins.
Compare

was about to suggest that, I had a old cdi earlier this year with similar symptoms . new gas valve cured it

 

[Riley]

I could potentially cap It. As I say the only thing I can't work out it is even if the gas valve is passing how can we smell it inside any gas passing should be going up into the combustion chamber which should be sealed

 

[ShaunCorbs]

I could potentially cap It. As I say the only thing I can't work out it is even if the gas valve is passing how can we smell it inside any gas passing should be going up into the combustion chamber which should be sealed

through the air intake bet you

 

[AMGasServices]

Do a mini tightness test on the gas valve using the p1 test point.

 

[Gas74]

If it's the one with the rubber tube between gas valve and fan this can go porous or crack. Had a couple with it.

 

[Riley]

No, solid looking plastic pipe from valve up to fan

 

[ed209]

Seems strange that as you say you can smell in room from RS boiler you'd assume that any internal leak would disperse through flue or air intake.
I found intermittent leak on new WB compact CDi turned out no olive on gas pipework in to boiler just paste, also had leak once on some pipework not showing on drop test but only leaked when boiler running.

 

[Elgordo]

Wind can blow gas back through air intake ,flue not properly sealed to outer wall wouldn't help .

 

[mfgs]

I have had a gas leak before on a compression fitting on the connection to the boiler. It only leaked when the boiler was running, so it would always pass every test. Yet when the boiler was running it would cause this joint to leak for some reason.
First thing would be to do a mini tightness test to see if the gas valve is letting by.

 

[Riley]

Just an update changed gas valve all sorted. Thanks guys

 

[ed209]

Which poses a question, if you have a gas valve letting by and no smell of gas and within allowance Mb drop can you let it go?
As I had this the other day on BR Avanta plus
The landlord opted to have it changed but was not sure if it would have been ok letting by 0.5 mb over 2 mins no smell of gas

 

[Atouchofgas]

Well obviously not as you've traced where the escape is, you need to repair it

 

[jonnyswamp]

No
If you know the gas valve is leaking, don't give the landlord/customer the option, just change it

 

[mfgs]

Which poses a question, if you have a gas valve letting by and no smell of gas and within allowance Mb drop can you let it go?
As I had this the other day on BR Avanta plus
The landlord opted to have it changed but was not sure if it would have been ok letting by 0.5 mb over 2 mins no smell of gas

Of course you cant leave it once you know its the gas valve. Its a safety device that has failed and is ID.

 

[Sim77]

had similar on Vaillant 412. It was gas valve passing. New valve fixed it. Took me way to long to figure it out.

 

[Riley]

had similar on Vaillant 412. It was gas valve passing. New valve fixed it. Took me way to long to figure it out.

Frustration more than anything

 

[ShaunCorbs]

Frustration more than anything

Leak test the gas valve out

 

[Riley]

I did mate. That was what confirmed it. I was just more concerned with why it could be smelt in the room

 

[ShaunCorbs]

I did mate. That was what confirmed it. I was just more concerned with why it could be smelt in the room

Coming out/filtering through the air tube is the only way unless broken/ damaged burner gasket

 

[Riley]

Was a weird one mate put the sniffer all round the case after letting the air clear. Not a jot. All seems fine now though

 

[ShaunCorbs]

Was a weird one mate put the sniffer all round the case after letting the air clear. Not a jot. All seems fine now though

Boilers are weird sometimes 😀 but least you sorted it

 

[ed209]

Just re read my posting and what I meant to say was if it was letting by on gas valve but you could not detect it with leak fluid/sniffer. This is the problem I encountered I could not find the leak even when Disconnecting from top of gas valve but was after the isolation of boiler so not on pipework and no smell whatsoever of gas, so what I'm saying is, it was all most certainly the gas valve but I couldn't prove that. Changed valve problem solved. But Technically could have let it go under the 4/8mb drop allowance on appliance with no smell of gas