Funny how that Gas safe Engineer didn't even blink when he got a reading of 0 ppm, especially when the CO alarm had gone off as well, and the appliance had been sealed off, whilst I can tell you if you get a reading of 0ppm, then that would have aroused some suspicions, clearly means something is wrong with the guys analyser, there is no way on this earth that you would get a real low reading of 0 ppm on an old boiler.
You obviously aren't in the gas industry and know f00k all. 0ppm is a regular occurrence and how complete combustion of gas should be.
A new boiler can be different as they are set to different criteria and there is a permissible CO level allowed as per MI's.
I also disagree that any minor dust can cause such a high reading in 10 days
Minor dust wasn't mentioned. A blocked primary air filter was though would that change the CO reading?
Just out of interest, what did this first RGI stand to gain by lying about the ppm and turning the boiler back on thus only charging an hour and missing out on the opportunity of upselling spares that aren't needed and possibly a new boiler!? No RGI would ever leave an appliance in a dangerous state.
Maybe, just maybe, the second RGI felt his nose had been pushed out of joint and blocked the filter himself to get a high reading and upsell to the client?
Original RGI comes back and cleans the mess and appliance is still safe again.
Try reading between the lines. We do this daily and have seen pretty much everything between us.
@Mikefromlondon Please if you have nothing useful to contribute then please don't as you are just making yourself look a bit of a d1ck. Oh and thanks for the life story it really added to the thread. Cheers for that.
Jon