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Ot Gas heater not working

Mebfab

Diamond
Joined
Jun 7, 2003
Location
Mebane North Carolina USA
My natural gas wall heater wont work. THe pilot light will not stay lit. Replaced the thermocouple. The pilot will light and stays lit as long as I hold in the buton. Normally after lighting I hold the button for a minute and the pilot stays on. Now it just goes out.

This is a very old unit. No electrical or electronic parts. No thermostat.

ANy thoughts??
 
Our local gas company will send an employee to your home and fix whatever is wrong with your unit. Charge, only, for parts not labor. They have full time employees to cover problems like this. You might check with your local gas company.
 
It actually electrical. The thermocouple generates a small voltage which holds a solenoid valve open. The solenoid is the gas valve. When you mechanically open the valve it heats the thermocouple until enough energy (volts X current) is generated and then the valve holds open. Loss of pilot stops the current and the solenoid drops out

The internal parts don't move much, but I have seen the small wires in the valve break. As mentioned above the element needs to be centered in the pilot flame. Also when you tighten the threaded end do not over tighten, it is an electrical connection ans as such cannot gas. Does the main flame blow the pilot out?

Last call is to replace the gas valve. They are usually available.
 
I have a buddy who sold propane with his dad for years. The other day I was having the same problem with my heater. He told me to take a straw and blow down the gas pipe and also blow the burner. I did that and also took a shopvac to all of it too. Works like charm now. Good luck.

Bernard
 
It actually electrical. The thermocouple generates a small voltage which holds a solenoid valve open.

Some of the older units use a capillary tube, actually the expending fluid holds open the gas valve. Been awhile since I worked on one, but it's real picky how you install the control end of the tube, assuming that's what you have.
 
Clean the orifice for the pilot light. If the flame isn't big enough it might not heat the bulb enough. I used to have to do that each season on my house furnace before I moved.
 
Some of the older units use a capillary tube, actually the expending fluid holds open the gas valve. Been awhile since I worked on one, but it's real picky how you install the control end of the tube, assuming that's what you have.

And I have messed with a few that took more than 1 minute to warm the bulb enough to keep the pilot on, one furnace required a little warming of the bulb with a propane torch in fact. Make sure the nut that fastens the capillary tube to the gas valve is tight too.
 
my old stove I bent the sheet metal down a little to direct the pilot flame more onto the thermocouple. make sure the pilot jet and venturi is clear of spider webs etc.
There should be a pilot adjusting screw on the valve. Often have to unscrew a big screw then under that is the actual valve screw. Just open it up a 1/4 turn or so and see if that helps.
Not a bad idea to turn it closed all the way, counting turns to close. then remove screw and clean tar off the tip seat. I use rubbing alchol. screw it closed all the way then count turns out to reset to original position.
Bill D.
 
My kid's boiler worked fine for about 10 years,l before the thermocouple quit. My back was really out of whack, then, so I got a furnace gut to replace it. Good for about a week.

Called me, out again, feeling a bit better, replaced it myself. ( I was IN the furnace business, 35 to 15 years ago, so was not , so not in over my ass. I Do know what I am doing.)

Lated a couple months, replaced, same, replaced, same. Place I used to get my thermocouples had a tester, Busy Beaver, HD, Lowes, don't. I went to a local dealer, closes at 5 PM, couldn't buy from them. Asked them to test the thermocouples I had replaced, and they were all "good", per the tester.

Why the furnace quit, I don't know. Why it worked when I replaced it, I don't know. I HOPE the one she had replaced without me keeps working. My local store told me that you do not want to replace with the "PlumbCraft" type, cheapos. The original, which I still had, was the brand that they sold, BUT, THAT thing lasted only about 10 years. Sealed unit.

The poster above is referring to a millivolt unit, electrical, NOT a tubular, capillary unit, it has wires leading to the gas valve.

I am beginning to think that my daughter's gas valve is the culprit.

My own gas boiler ran for over 30 years with the same thermocouple.

Cheers,

George
 
My kid's boiler worked fine for about 10 years,l before the thermocouple quit. My back was really out of whack, then, so I got a furnace gut to replace it. Good for about a week.

Called me, out again, feeling a bit better, replaced it myself. ( I was IN the furnace business, 35 to 15 years ago, so was not , so not in over my ass. I Do know what I am doing.)

Lated a couple months, replaced, same, replaced, same. Place I used to get my thermocouples had a tester, Busy Beaver, HD, Lowes, don't. I went to a local dealer, closes at 5 PM, couldn't buy from them. Asked them to test the thermocouples I had replaced, and they were all "good", per the tester.

Why the furnace quit, I don't know. Why it worked when I replaced it, I don't know. I HOPE the one she had replaced without me keeps working. My local store told me that you do not want to replace with the "PlumbCraft" type, cheapos. The original, which I still had, was the brand that they sold, BUT, THAT thing lasted only about 10 years. Sealed unit.

The poster above is referring to a millivolt unit, electrical, NOT a tubular, capillary unit, it has wires leading to the gas valve.

I am beginning to think that my daughter's gas valve is the culprit.

My own gas boiler ran for over 30 years with the same thermocouple.

Cheers,

George

I had one furnace with the "millivolt unit" aka "power pilot" and I HATED that thing with a passion :-)...give me an old fashioned capillary tube anyday :-). Standing pilots are a thing of the past anyway in todays world, a dinosoar...so you now get a furnace where the board goes out and the board alone costs $500...for a GD printed circuit board.

They also used to make a thing that would relight a pilot before the thermocouple cooled, for the furnace in my Ma's house that might have been a good idea, a freak downdraft would blow the pilot out about once a year. If the pilot gets relit right away then the PITA thermocouple never becomes an issue.
 
I had one furnace with the "millivolt unit" aka "power pilot" and I HATED that thing with a passion :-)...give me an old fashioned capillary tube anyday :-). Standing pilots are a thing of the past anyway in todays world, a dinosoar...so you now get a furnace where the board goes out and the board alone costs $500...for a GD printed circuit board.

IF the board is available!

If mine ever goes, I think I'll probably switch everything over to industrial control electronics.
 
"...the board alone costs $500...for a GD printed circuit board."

Home heating equipment should NOT have any circuit board electronics in it. Buddy
here at work blew out the low water cutoff board on his new boiler during the recent
power outage thing from the storms.

I looked at it, it had what seemed to be USB connectivity to the other boards in the
unit. Crazy. Surface mount components on it. No way to troubshoot. Next up is
a woodstove that has to connect to the internet before you can light it.
 
Hey Jim don't laugh. I am sure that they will do this soon in California for wood stoves. that way it will lock up the door so you can not use it on a no burn night. Spare the air you know.
Bill D.
 








 
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