Problems With Gas Valve-Old Iron Core Furnace

HAVCN · 03-01-2009, 03:40 PM

To whomever can help,

I have an older Holland Furnace w/Iron Heater Core and standing pilot thermocouple. The pilot went out and I replaced the thermocouple w/new kit. The pliot then stays lit and the valve for the burner fires up as normal from the main electric switch and when I turned the themostat down and then up. One problem though...when the desired room temp is met, the valve shuts off and so does the Pilot. I then have to relight unit. The valve also never closes until the themostat tells it to. Is this normal or what? No control modules on this unit. Honeywell Gas valve 1/2 x 3/4 and continuous pilot. The blower appears to recycle (off and on). Anticipator, Thermostat, and 24v Transformer appears to be working properly. I suspect the Gas Valve itself as the culprit. Whaduya think. Can anyone please help.

yuri · 03-01-2009, 04:34 PM

Post some pics of that furnace and the burner. I have worked on real old units with conversion burners etc. The burner may be sucking out the pilot when it shuts down. If it is that old do you really want to take chances with it cracking and you get CO poisoning? I am sure it is a lot less than 50% efficient.

kenmac · 03-01-2009, 06:29 PM

When you say you replaced with a new kit.. Do you mean new pilot assy as well as t. couple ?? Like YURI said . When the main burner goes out . It sucks the pilot out. I have also worked on these in the past. You need a good strong pilot to withstand the suction of the burner when it goes off

Plumber101 · 03-01-2009, 08:24 PM

Could be as well as the standing pilot assy needs cleaned

HAVCN · 03-02-2009, 03:07 PM

Hey what's up Kenmac; Yuri...

The ans is Yes, I replaced the Entire assy...Thermocouple and Deflector assy. The new pilot is very strong but old pilot was'nt going out with the old assy. I'm feeling you on the sucking action but it's not quite hittin the spot. Everything is lined up the same. Had to omit (1) screw. There is a long gas tube and another apparatus that looks like some type air flow vent. It runs parallel alongside the burner tube. About a foot long w/little holes in it. Im still hitting a brick wall. A new valve is about $200.00 bucks. Were in a recession...Whew! Any other thoughts....Im all open for it....thanks...

HAVCN · 03-02-2009, 03:10 PM

Hey what's up Kenmac; Yuri...

The ans is Yes, I replaced the Entire assy...Thermocouple and Deflector assy. The new pilot is very strong but old pilot was'nt going out with the old assy. I'm feeling you on the sucking action but it's not quite hittin the spot. Everything is lined up the same. Had to omit (1) screw. There is a long gas tube and another apparatus that looks like some type air flow vent. It runs parallel alongside the burner tube. About a foot long w/little holes in it. Im still hitting a brick wall. A new valve is about $200.00 bucks. Were in a recession...Whew! Any other thoughts....Im all open for it....thanks...

kenmac · 03-02-2009, 05:52 PM

Replacing the gas valve will not help. What you ( I have had to do this) Take the new pilot assy & open up the holes (orifice) a little so that you will get a larger pilot flame. The new pilot assy will not provide enough flame to keep from getting sucked out. If it's good , re- install the old pilot assy & it will stay on