C
cosmic-alchemy
Hi guys :bow:
Im very newly qualified and have gone from an apprenticeship with a big company to working on-site a shopping/residential development, and I'm just trying to find my feet after coming across a few confusing things....
I'm commissioning Keston C36 Combi and Keston Qudos 28s boilers, all with U6 meters. An issue arose today where one of the other commissioners struggled to gas rate a block of apartments because:
When 2 taps were turned on fully to operate the combi boiler at the correct rate as per the MI's, the pressure at the taps reduced dramatically before a gas rate could be completed and the boiler overheated, and cut out due to inadequate mains pressure.
But when I when I was asked to go over it I didnt have this problem.
Keston state that it should take 95 seconds for 1 cubic meter of gas to pass through, and thats all thats required to make sure the gas rate is correct. However, it was taking around 100-105 seconds for one cubic meter of gas to pass, 10-ish seconds too many. I tried with the bathroom basin and bath taps running, then tried with the bathroom basin and the kitchen taps although I was unable to turn the kitchen tap on fully without flooding the place.
Obviously, there's the 5% tolerance on the final figure, and the stated Max DHW Input is 40kw/136,500btu/h (Gross CV) But I'm really struggling to figure out whether its within that tolerance. The highest time I recorded was 103 seconds. I don't get it because its not the usual 2 minute testing procedure. Will the 2 min procedure work the same?? Its gotta be me being an idiot?!
Thanks in advance for your help, Freya :bow:
Im very newly qualified and have gone from an apprenticeship with a big company to working on-site a shopping/residential development, and I'm just trying to find my feet after coming across a few confusing things....
I'm commissioning Keston C36 Combi and Keston Qudos 28s boilers, all with U6 meters. An issue arose today where one of the other commissioners struggled to gas rate a block of apartments because:
When 2 taps were turned on fully to operate the combi boiler at the correct rate as per the MI's, the pressure at the taps reduced dramatically before a gas rate could be completed and the boiler overheated, and cut out due to inadequate mains pressure.
But when I when I was asked to go over it I didnt have this problem.
Keston state that it should take 95 seconds for 1 cubic meter of gas to pass through, and thats all thats required to make sure the gas rate is correct. However, it was taking around 100-105 seconds for one cubic meter of gas to pass, 10-ish seconds too many. I tried with the bathroom basin and bath taps running, then tried with the bathroom basin and the kitchen taps although I was unable to turn the kitchen tap on fully without flooding the place.
Obviously, there's the 5% tolerance on the final figure, and the stated Max DHW Input is 40kw/136,500btu/h (Gross CV) But I'm really struggling to figure out whether its within that tolerance. The highest time I recorded was 103 seconds. I don't get it because its not the usual 2 minute testing procedure. Will the 2 min procedure work the same?? Its gotta be me being an idiot?!
Thanks in advance for your help, Freya :bow:
