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Flue gas reversion or "bad propane"?
I just finished up a really lousy week of work with a really aggravating service call.
Due to the colder than normal weather we have been experiencing here in NY we haven't made the transition into A/C season yet, and as a result work has been slow and my boss has been sending two guys out on what are normally one man service calls.
Usually this is a good thing and makes the day go by faster, but today I was paired up with a technician who is older and more experience than myself. He likes to rush through everything so he can get an early start on getting drunk, and he thinks I get "too crazy" about "minor details like combustion analysis". He thinks CA isn't necessary and his experience gives him all the answers.
Anyway, we were sent out on a no heat call. The customer has a five year old Bosch Greenstar Combi unit fired by LP. My wizard co-worker doesn't even look for the fault code (EA, no flame detected) and just starts opening up the gas pipe union, assuming the customer is out of propane. I pulled the igniter and flame sensor out and was quite surprised by my discovery. The flame sensor was extremely corroded, greenish colored and broke off the porcelain as soon as it was touched. The electrodes appear to have been meltedand have a gap the size of the grand canyon. The first thing I thought of was to check how the boiler was vented, because the only other time I have seen anything like this was on Munchkin/Purefire boilers that were vented concentrically. I found the intake and exhaust were separate 3" PVC pipes terminated right next to each other. The vent was installed correctly according to the manual, but not what I considered the best way. After picking up the part I took out my Testo 320 to check combustion. Of course this angered Einstein, he considered the job done after the boiler fired up. It's Miller time!
That didn't deter me, I put the unit into high fire and took a flue sample. My Testo shut down on sensor protection because CO production was in excess of 4000 PPM. The professor didn't consider this to be a problem and concluded that it was a result of "bad propane"! He became very angry when I suggested that the boiler was unsafe to operate. He thought that even with "bad propane" the equipment was fine because it's only five years old....
What do you guys think? All thoughts, opinions and suggestions are welcome.