Water in boiler causing flame to drop out

mattyd

I've been in the oil-heat trade for over 8 years now and while I understand that isn't very long compared to some of the more seasoned veterans I thought I had seen most everything that could cause an oil burner to stop running...that was until this past Saturday. I am posting this because I want to know if anyone else has had this happen and also to make some of the less seasoned professionals aware of it as a possible cause for no-heat calls.

I recieved a call from a customer stating they had no heat or hot water, the system is a Weil-Mclien GO4 with a Beckett AFG burner, approximately 10 yrs old. The customer told me the hy-vent on the top of the boiler had leaked water over night and he had taken the pressure of the system and replaced it earlier that day (when I say leaked I mean LEAKED, there was easily a 1/2" of water on the floor all around the boiler in the utility room). Anyway...the burner would fire and then sputter and drop it's flame at the 15 second mark when the interrupted ignition primary control would stop the ignitor. After about an hour and multiple checks for the cause (voltage to the motor, burner coupling in ok shape, pump pressure while running, which was 140psi) I decided to see what would happen if I tapped the reset button as if I was bleeding the system to force the ignitor to run for a longer period of time. What I found was that the burner ran the entire 4 minutes and then continued to run. I opened the sight door and saw that water was dripping down through the flue-ways on all 3 sections of the boiler (having been a firefighter the cause for flame loss was suddenly VERY obvious) water on a flame = no more flame. After I ran the boiler for that 4 minutes and then it continued to run it was obvious that the flue-ways were drying out. The boiler has been running ever sense and I called the customer today to confirm that they hadn't had any further issues...what I want to know is if anyone else has ever seen this type of situation occur, where a leaking hy-vent on the top of a boiler saturates things so badly that it stops the burner from running?? This is a new one in my book and I feel like a bit of a fool after spending an hour + attempting to diagnose a "fuel delivery issue" that didn't actually exist. Any thoughts, opinions, experiences on this type of situation would be GREATLY appreciated!! Thanks in advance!!

billtwocase

oil and water

don't mix. I have seen many as you described. As soon as the chamber dries, off she will go. I usually leave the inspection door open slightly to keep it running, Cold wet chimneys are no fun either

mattyd

Thank you!

I'm glad I'm not finding something new!  The chimney was cold and damp too but nowhere near as bad as the chamber & flue-ways. This is the 1st time I have personally run into the situation, it certainly had me scratching my head for a few moments!

John S_2

under water

Had a Riello once in a basement that had flooded. Thing was still running! No flame of course. Stuck in prepurge due to a shorted (false flame sense) cad cell. Dried it off and put a new control on it. Fired right up! Replaced the motor too, just to be safe, but otherwise it was apparently unharmed.