Old furnace doesn’t work. It’s a Holly Stubby Model 38FD.
Never heard of this manufacturer.
Sure you have this right? Is this a regional manufacturer?
As to #2, usually the serial number is coded to identify the year the unit was built.
The house was built in the 30’s. Other than that, I have no clue how old the furnace is.
Is this a floor furnace or a wall furnace? I have tried the google for Holly Stubby, and have come up with very little info. The company appears to be long out of business.
In general, the thermocouple, or more likely millivolt thermopile (also called a generator), is located so that it is directly in the pilot flame. A thermocouple will have what appears to be thin copper tubing coming from it and going to the gas valve. A thermopile will have two wires, one leading to the gas valve, the other to the thermostat. There may be safeties of some type involved in the circuit as well.
You access the thermocouple/thermopile through the same opening that you use to light the pilot. They are usually not inordinately difficult to access, but sometimes you need to be pretty limber to get to them. Mounting methods vary, so you’ll need to examine it to figure out how to remove and replace it.
If you’ll post a better description of the furnace, I’m sure you can get more specific answers. Also, what leads you to believe the thermocouple is the issue? Or is this the next step in troubleshooting the thing?
It’s a wall unit. The pilot is in a sealed system accessable through a small hole in the top. Basically, you would have to use a long fireplace match to light it. The pilot light stays lit but the burner does not turn on when the thermostat clicks over. The thermostat is working since I tested it with my multimeter.
I’ve seen this before and it was the thermocoupler then. I know I could test it by turning off the pilot and listening for the click of the gas valve being shut off, but then what’s the point? If I cant get to it to repair it, then I have to call a heating tech anyways, and then I might as well buy a new cheap-ass model that will last at least three years until this house is sold.
I was crawling around under the house trying to find the thermocouple, and finally realized… There Isn’t One!
It is not pretty under my house. Lots of spiders. Only a foot or so of clearance.
This is hard won knowledge!
So, if no thermocouple, then why won’t the dang pilot light when you turn the pilot knob and stick a long “fireplace” match in there???
Cause the match isn’t long enough! When I went under looking for the thermocouple I even tried lighting it from below; no dice. I had to tape two long matches together in order to reach all the way down to the pilot fitting.
You can’t even see the pilot assembly until your lit match is almost all the way down there. I went through dozens of fireplace matches before I learned this. Here I am, waving these lit matches blindly in that tiny dark hole. Now that I got it lit it’s comical.
Okay, hope this helps out anyone else with a 1930’s floor heater they can’t get relit.
I had a friend who bought such a house in the spring. It wasn’t until the next winter that she realized that the ‘piece of trash’ that the previous owner had left hanging next to the furnace and which she had thrown out – a metal rod with a metal binder clip screwed to the end – actually had a functional purpose.
You saved me a lot of trouble. I lit the pilot of this oldie by taping two furnace match sticks together- why the hell is it so far down there?..O