Possible gas valve passing on ideal isar - but why is there no drop??

[beesley121]

Hi guys,

noticed a smell of Gas the other day outside in my garden, I have a LPG cylinder so thought it was that but then narrowed it down to my boiler. Seems the gas is coming from the flue so I'm assuming the gas valve is passing but when I've done a drop test, I got no drop. That doesn't make sense to me so can anyone explain why?

 

[beesley121]

Wow, must knew I was as clever as everyone else. Seems we all don't know the answer lol

 

[lame plumber]

coz it isnt passing if the tightness test doesnt show a drop at all.

 

[kris]

Best thing to do if your still worried is use a gas sniffa thats the best way but if youve no drop then youve no leak, but could it be unburnt gas left in chamber or somethin along that lines or maybe pocs your smelling, or possibly a neighbours

 

[Chalked]

My neighbours was the same on firing. Was a software issue

 

[Ermintrude]

Valves just lifting on pre purge. Ideal mini awful for it

 

[beesley121]

I used a sniffer, went nuts when I stuck it in the flue and the boiler had been turned off all night. Was think it might be detecting a residue of the poc. We can normally smell is just as boiler lights which is normal, but as we are not using the hw and heating anywhere near as much now we in the summer, we keep getting smells of gas. Neighbours flues and both up high near eaves so would have thought it was theirs we are smelling

 

[nysk2008]

why dont you test the gas valve at the p1?

 

[BLOD]

as nysk says do a blip test at p1 at the gas valve.

 

[Pssst]

It is quite possible to have a leak and/or a smell of gas when there is no perceptible drop on a WG even in domestic premises.

The final solution is to test using an electronic gas detector of some kind at the relevant points within the boiler combustion chamber.