Huge gas pressure drop between meter and boiler. Help!

[BlueLoo]

A few have asked if I can send pictures- do you have to convert to a URL as I cannot seem to just attach a pic!

Be careful with any private info you may share.

Take a pic on the phone and use the "add file" option in the reply box.

You can crop or redact the picture on your phone easily.

 

[ScottishGasMan]

I have the certificate-

Central heating mode
Burner operating pressure 20 millibar

domestic hot water mode
Burner operating pressure 20 millibar

When he and the Vaillant engineer tested at the boiler this week it was 13.5. At the meter it’s 20 millibar (tbc).

The gas flame on the cooker is not affected, the pipe work has not been changed for 20 years and 15mm inlet complies with minimum spec.

assuming static readings are correct os there anything that can cause this drop other than a blockage running up to the boiler. If that were the case you would expect some debris in the valve the engineer removed?

What I'm saying is, the Boiler inlet working pressure physically could not have been 20mbar, if it was also 20mbar at the meter, it's not possible. So these readings mean nothing. Perhaps he made a rookie mistake during testing, or doesnt know how to correctly test them, or what seems to be much more common these days is that the reading was just fabricated.

 

[DP]

fabricated

Or copied from the data sheet in the MI

Perhaps it is just me, I have yet to see 20mb inlet pressure on a steamer going pedal to metal unless it is LPG and even that would be wrong

 

[FiremanT]

Or copied from the data sheet in the MI

We will see. The gas rate (m3/hr) will probably match the book

 

[ScottishGasMan]

We will see. The gas rate (m3/hr) will probably match the book

Mind getting called to one a few years back under warranty. Pro 28, getting about 31Kw Gross on commissioning testing. Young installer newish to the game, part of a big council contract, he was concerned it was over gassed.

Checked it all out, explained to him and his manager that it was spot on, as the 28 in the name referred to actual heat out put, and they stopped for two seconds and looked at the data tables they would have seen gross gas input was about the 31kw mark.

Manager started to scold the young guy when I interrupted and explained that hes probably your only employee that has actually done a gas rate when commissioning rather than making it up, check the other log books I'll bet they all have the same thing wrong in them. He done the right thing phoning for help as he thought there could be a danger, rather than just copy/pasting the same info into every sheet.

 

[fixitflav]

Is your boiler quite old?
Modern boilers have Zero Governor’s. If you try to measure the burner pressure it will be zero or less .

Yes, installed in 1999. It's an Ideal SE50, still works fine. Apologies, I'm not up to speed with developments.

So the benchmark is wrong. If he measured and meant the inlet pressure then it would , given the pipe run, would hardly likely to be 20mb, reflects zero pressure loss.

Agreed

 

[fixitflav]

Checked it all out, explained to him and his manager that it was spot on, as the 28 in the name referred to actual heat out put, and they stopped for two seconds and looked at the data tables they would have seen gross gas input was about the 31kw mark.

I've had to explain to certain electrical engineers that the rated power of an electric motor is the shaft output power, not the electrical power going in.

 

[fixitflav]

burner operating pressure, and appliance inlet operating pressure are two completely different things

I know, that's why I said Perhaps he meant boiler inlet pressure.

 

[ianmcd]

Mind getting called to one a few years back under warranty. Pro 28, getting about 31Kw Gross on commissioning testing. Young installer newish to the game, part of a big council contract, he was concerned it was over gassed.

Checked it all out, explained to him and his manager that it was spot on, as the 28 in the name referred to actual heat out put, and they stopped for two seconds and looked at the data tables they would have seen gross gas input was about the 31kw mark.

Manager started to scold the young guy when I interrupted and explained that hes probably your only employee that has actually done a gas rate when commissioning rather than making it up, check the other log books I'll bet they all have the same thing wrong in them. He done the right thing phoning for help as he thought there could be a danger, rather than just copy/pasting the same info into every sheet.

i went to a warranty call for a noisy boiler, installer had printed off his FGA readings and taped on the front of the boiler, aye great mate, but working inlet pressure is 6Mb, he says but the readings are correct, I really worry about the FGA brigade that think it is the be all and end all of everything

 

[fixitflav]

I have the certificate-

Central heating mode
Burner operating pressure 20 millibar

domestic hot water mode
Burner operating pressure 20 millibar

When he and the Vaillant engineer tested at the boiler this week it was 13.5. At the meter it’s 20 millibar (tbc).

The gas flame on the cooker is not affected, the pipe work has not been changed for 20 years and 15mm inlet complies with minimum spec.
assuming static readings are correct os there anything that can cause this drop other than a blockage running up to the boiler. If that were the case you would expect some debris in the valve the engineer removed?

Out of interest, what made you go from a regular boiler to a combi? IMO installers pushing combis, often for no good reason, is bad, but doing it without any thought to the much higher gas flow is a lot worse!

I'm not clear what the experts (I'm a DIYer) think should be done.
Is it
a) as the system appears to work OK, do nothing
b) get Gas Safe involved, and possibly land the installer in trouble (he may deserve it!)
c) modify the pipework to get below 1mb drop, presumably at the installer's expense.
d) something else I haven't thought of

 

[FiremanT]

Out of interest, what made you go from a regular boiler to a combi? IMO installers pushing combis, often for no good reason, is bad, but doing it without any thought to the much higher gas flow is a lot worse!

I'm not clear what the experts (I'm a DIYer) think should be done.
Is it
a) as the system appears to work OK, do nothing
b) get Gas Safe involved, and possibly land the installer in trouble (he may deserve it!)
c) modify the pipework to get below 1mb drop, presumably at the installer's expense.
d) something else I haven't thought of

C) : Give the installer a chance to rectify (we have all done things which with hindsight we would not have). If no joy then go to B.

 

[ScottishGasMan]

Out of interest, what made you go from a regular boiler to a combi? IMO installers pushing combis, often for no good reason, is bad, but doing it without any thought to the much higher gas flow is a lot worse!

I'm not clear what the experts (I'm a DIYer) think should be done.
Is it
a) as the system appears to work OK, do nothing
b) get Gas Safe involved, and possibly land the installer in trouble (he may deserve it!)
c) modify the pipework to get below 1mb drop, presumably at the installer's expense.
d) something else I haven't thought of

He didnt, hes got a system boiler.

 

[Harry Bloomfield]

He didnt, hes got a system boiler.

My mistake too - I read it as it having an heat only or system boiler replaced by a combi..

 

[fixitflav]

My mistake too - I read it as it having an heat only or system boiler replaced by a combi..

Not with you and ScottishGasMan.
In #43, replying to "Was the old boiler a combi", OP says "No. Was an eco tec plus- 2006 model."

 

[ScottishGasMan]

Not with you and ScottishGasMan.
In #43, replying to "Was the old boiler a combi", OP says "No. Was an eco tec plus- 2006 model."

Yea, and ecotec plus comes in Combi, System or heat only versions, he later says its a 630 Which is a system boiler.