You know nothing at all about this particular boiler installation, and you may be generalising, but to cast aspersions on the quality of the work, or the standard or condition of the plumber's electronic equipment is totally uncalled for.
Maybe your engineer failed to explain what the efficiency #s relate to when using a FGA , these boilers were somewhere in the region of around 70% efficient , this was a result of the cast iron heat exchanger coupled with the low CO2 due to shed loads of excess air in POCs.
Thank you for your pleasant response. Well your figure of ' somewhere in the region of 70%,' is a lot better than the 55% that was given out on this forum, by one of the ' experts.' It is also closer to the 78% given in the manufacturer's manual. ( Which is where I extracted my figure from). It appears that everyone is an expert. I can only offer the figures from the manual, and the figures given to me by my gas fitter. He told me that the boiler was quite efficient, and the figure he gave was definitely 80%. I don't know how his very expensive looking bit of kit works, but I assume that some organisation checks his work from time to time. I have an electrician who does work for me from time to time, and I know that his equipment and work are checked and have to pass a set standard. Surely the gas industry has something similar?
You are still missing the point on two issues.
First I believe, without being a***d to check, Agile gave you the 55% figure. This was your first mistake. Ignore this buffoon.
Second, the figure quoted by your fitter is, as others have highlighted, a completely different reading based on something he probably doesn't understand.
To put it closer, but by no means in a definitve manner: Two boilers both running combustion efficiency figures of 90%. Boiler A uses 100Ft3 of gas to heat a jacket of water to 75 degrees. Boiler B uses 1Ft3 to heat a jacket of water to 75 degrees. Which is more efficient?
Search me ? ? But ask Dan if you dare ! ! Also, unaccustomed as I am to this forum, or any other for the matter, I was hoping that everyone concerned realised to which post I was referring. I thought, wrongly, that the bars at the bottom of the page, were the ones to click when answering a post. I am pretty positive that everyone, realised that I was answering the guy that you called ' the buffoon.' Oh Boy, am I glad I didn't upset you too. Best regards, Cooder.