Boiler using excessive gas after service

[DP]

So a gas meter only registers legitimate gas usage?

Righto.

.??? What are you on about
If the meter registered a gas leak, the leak would be quite large and there could be a danger of explosion

 

[BlueLoo]

An older boiler like this has the power input set by varying the gas supply pressure to the burner. The installer or servicer checks and if needed resets the pressure on the gas valve. The gas supply pressure from the meter is about 21 mbar and a typical burner pressure about 5 to 12 mbar so little scope for very wide misadjustment.

If the burner pressure is too high and if all the burner is lit then the additional heat is transferred into the system water so the additional power is not lost.

The one potential way for the gas not to be burnt is if part of the burner is not ignited fully. But that is unlikely as unburnt gas usually quickly lights if there is a flame nearby. That is about all the servicer could check and is very unlikely.

Good post.

I think its either a leak somewhere (highly unlikely obviously because surely you'd smell it, or it is outside, etc). Or the OP is mistaken about the rise in gas usage being unwarranted.

I really do think it is probably the later.

I would suggest the OP do a second check on gas usage and his methods of checking it. He might realize a mistake somewhere.

You could eyeball gas usage under full load as well by reading gas used over a know period with the boiler at full tilt. Perhaps do a meter test with timed boiler firing from the CH and HW cold to hot. A bit rough maybe but not impossible.

How likely is it that the boiler is not burning all of the gas it consumes?
Is that even possible with modern boilers?

 

[ianmcd]

Is that even possible with modern boilers?

Read TFP it is not a modern boiler, it is a fixed rate boiler

 

[DP]

You do know piping can leak from any position in the system?

If tightness test has been carried out, how can piping be leaking ( not come across piping phrase before though)

 

[DP]

Who gives a **** if the joints are tight, its a system wide leak you would be looking for.

Blueloo, do you want to read what you have written again?

If the joints are tight, how can there be a leak

 

[DP]

If you've unexplained gas usage, I'd be doing a system survey with a sniffer

Does not compute. Then What is the purpose of the tightness test.

Your posts on gas etc are causing head scratching for the gas engineers as information or advice you are giving is often not correct.
An end user could end up following what you say and end up in deep doo doo even though your signature says you are not a pro. Some of your posts that has happened where someone seeking help has latched onto your words of wisdom

An example of above is you do not know what the function of tightness test is since you keep saying there could be a pinhole hence piping issue. In 30 years I have not come across a pinhole in pipe conveying gas ( perhaps just not enough years under my belt)
Then you say gas meter register could be used to find a gas leak. I can assure you you will not be able to do that, guaranteed.
Gas could be leaking, no movement seen on the meter AND no smell, yet there could be a leak in the system or piping as you say. Clearly Google is not your friend here

Incidentally, basic problem solving, wish was easy as that. If it was that basic a person of your working knowledge would be walking in the park

 

[DP]

Gas valve passing gas but no ignition.

In theory can happen, and the end user would be able to see flame on the burner post shutdown. Unburnt gas passing? Not a chance- think about it why not.

 

[ianmcd]

You do know piping can leak from any position in the system?

Yes, course you do

Give it a rest eh lol.

Of course I do, hence why you would carry out a TIGHTNESS TEST,

Ok, well tightness test says to me its a joint test

well how the feck can you test only joints ? you are so completely wrong, please go and bug some other poor people genuinely looking for proper advice rather than your deluded ramblings , this is a site where DIyers ask for advice, not for you to try and be a smart arse

 

[BlueLoo]

And your point was caller ?

So how would you approach the problem?

 

[ianmcd]

So how would you approach the problem?

I would start with a tightness test, but I am a professional not a google warrior

 

[ianmcd]

You would detect the unburned gas coming from the flue, no?

and if it is a top floor flat, do you absail down , or get a very big ladder, or do you follow the correct procedure for testing for gas valve let by ?

 

[HERTS P&D]

Why are the Diyers arguing with Qualified Gas Engineers??

Andy

 

[ianmcd]

That would be part of a system wide, point-point test wouldn't it?

I dont know what a "system wide, point-point test" is, I know what a tightness test is and I know what a let by test is, maybe you can enlighten me, I have been missing out on this point to point test all these years

 

[CBW]

Why are the Diyers arguing with Qualified Gas Engineers??

Andy

Dunno, but mods are letting some threads run on and on (like Ariston - I’ll get my coat)

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We don't read all posts.
Someone has to raise an alert

 

[HERTS P&D]

Don't feed the troll!

Andy