warm air heating

[marleyco]

Hi,
Father in law just moved into new house. His heating bill has been estimated by previous occupant(the owner). Based on his gas consumption.
THe landlord has had safety check carried out and passed 2 fires, the warm air and hot water. I told him I'd gas rate them, all is ok except the warm air is rated at 24kw which according to data badge should be 11.6kw. Have a working pressure of 19.5mbar at meter, 17mbar at gas valve and burner pressure of 15mbar which is 0.5 under what it says on data badge.
It's there about correct, although maybe a bit low on gas inlet working pressure.
Any ideas what the problem could be?

Thanks

 

[gasmarc]

what the burner pressure suppose to be ?

 

[marleyco]

15.5, getting 15

 

[southcoastboile]

are you sure you have done the calculation correctly?, also sounds like the gas pipe is undersized, would be a good idea to run all appliances while checking wp at warm air unit just to see if it has any effect.

 

[marleyco]

Done the calculation twice and once from corgi book. I gas rated other appliances and are ok. It's an imperial meter, takes 42 seconds for one revolution

 

[Mbear]

The fires pilots are turned off during the gas rate yes? Also if they are turned the ffd's may have failed-therefore still letting gas through

This might seem a bit OTT but is it possible that the injector/s are oversized ie LPG injector/s.

Over gassing equals ID.

 

[Mbear]

Done the calculation twice and once from corgi book. I gas rated other appliances and are ok. It's an imperial meter, takes 42 seconds for one revolution

I get the same gas rating based on meter and rev timing.
26kw gross 23.5kw net
Defo no gas leak?

 

[southcoastboile]

ok, i just did the calculation and came up with 26kw, and if all other appliances checked out ok then it seems you are doing it correctly, i still think the gas pipe is undersised you should hae 20mbar wp at meter and 19mbar min at appliance, you need to check it with all appliances fired, the fact the bp is ok indicates worn/ incorrect injector on warm air unit.

 

[marleyco]

Yeh, pilot's are off. The guy that passed it is out tomorrow to check it. I noticed on his check sheet, all his readings are exact to data badge. Think he's been in a rush. Thanks for advice, was really just trying to understand it before he passes it again tomorrow, ha

 

[southcoastboile]

if you are only getting 17mbar wp at wau then you could ar the instalation, thats why i sugested checking it with all appliances running, i bet it will drop even furthur, if the wau then doesn't maintain its bp of 15.5mbar it is id, should be turned off and not used either way as you are getting a gas rate that is miles out

 

[marleyco]

I never checked for gas leak to be honest, as safety check said it passed. It could be leaking after valve now you say it, although I never heard or smell it. Sorry south coast I forgot I checked working pressure at gas valve with others running and it was slightly less, half a millibar I think. Meter is really close so although pipework may be under sized it might not be showing as much over short distance. I agree, as the gas rate is over double it must be classed I.d I would have thought. I will try remember to post the gas engineers outcome tomorrow. If it passes and is still the same, what to do? AS I haven't been called to look at It, is this where I step in as a care of duty, bearing in mind its my family and my kids will stay there at times

 

[marleyco]

Oh, further to him passing gas appliances. Balanced flue fire was one of them, where decking has been fitted around the flue so only half is exposed, after I seen it he has been back to cap pipe. No form to I.d it as it would contradict his pass earlier this month

 

[Mbear]

Oh, further to him passing gas appliances. Balanced flue fire was one of them, where decking has been fitted around the flue so only half is exposed, after I seen it he has been back to cap pipe. No form to I.d it as it would contradict his pass earlier this month

Do u really want to get him back out to a family members house. Does he have spurs on the heels of his boots?

 

[marleyco]

Ha, he works for a reputable company. I really don't want him back but its who the landlord uses. HOpefully they send someone else out. I'll prob have to kick up a stink after tomorrow.

 

[Mbear]

Ha, he works for a reputable company. I really don't want him back but its who the landlord uses. HOpefully they send someone else out. I'll prob have to kick up a stink after tomorrow.

I would be threatening with riddor. He's clearly ignored ignored an ID

 

[southcoastboile]

i think a ridor may be a bit extreme in this case although i do think you should threaten to issue one, hopefully they will sort it for you, seems like the guvoner may need replacing although depends on time of day as high demand could give you a 1mbar drop at meter.

 

[jtsplumbing]

Get the governor on the meter replaced , these things causeing lots of problems, Lots of posts about governor faults !!