I called the gas company in to do a routine safety inspection over the summer. One of the things the technician did was inspecting the furnace. At that time, he removed the cover over the burners and checked whatever he checks. I was watching and it seemed to me the pilot flame was much larger than what I expected to see. The tech said it was probably just he way it was back when the furnace was manufactured. I would very much appreciate your opinion. I took some pictures and movies (see below).
The unit is a forced air natural gas furnace (with standing Pilot) and with an A/C Evaporator on top. The house was built around 1966 and as far as I know this may be the original furnace and A/C unit. The information below is from the labels on the unit.
Gaffers & Sattler Corporation
Forced Air Furnace Model number: 125 FEF
Evaporator Model number: 50/60 TV H5
The Standing Pilot Valve Body says “Thermac Controls Company of America Gas Valve” 25V; 0.4A; 60cyc; NEC Class-2; ˝ PSI; G-LP; Part No. T-254
The furnace seems to be operating the same as it has for years. The thermostat controls and temperature regulation seems correct. The squirrel fan blower goes on and off at the expected times and sounds ok. All the connections I checked are not loose.
The pilot assembly in the picture below has three leads from the pilot valve body. I'm familiar with what the thermocouple in the middle does. I don't know why there seems to be a second gas line. Can you give me a quick tutorial on how the pilot works?
The lead on the left comes from a connection on the pilot valve body labeled “Pilot” with a screw next to it labeled “Pilot Adj.”. The lead in the middle comes from a connection on the pilot valve body and looks like a temperature thermocouple. The lead on the right comes from a connection on the pilot valve body labeled “Bleed” with a screw next to it labeled “Reg Adj.”.
Pictures of the pilot light flame:
And some movies:
1) Standing Pilot flame (99 sec video):
2) Burner flame (24 sec video):
3) Burner flame with cover on and blower running (21 sec video):