Go Back  DoItYourself.com Community Forums > Heating, Cooling, Air Conditioning, Ventilation and T-Stat Controls > Gas and Oil Home Heating Furnaces
Reload this Page >

older floor funace needs thermostat but old one is gone and I don't know what to

older floor funace needs thermostat but old one is gone and I don't know what to

Old 01-02-11, 07:29 PM
Thread Starter
Join Date: Jan 2011
Location: usa
Posts: 2
Upvotes: 0
Received 0 Upvotes on 0 Posts
Wink older floor funace needs thermostat but old one is gone and I don't know what to

My friend has a floor furnace with no thermostat just two wires sticking out off the wall and the old one has been gone for a long time. her uncle told her he used to attach a battery to the wires and the furnace would kick on. well I bought a thermostat with batteries but It didn't work, the furnace doesn't have any power just the gas. so I got two wires with alligator clips and a 9-volt battery clip each wire to the battery and furnace kicks on but after a while it shuts off. can't find any info on the furnace does anyone have anyIdeas that are better than A 9-volt battery hanging from the wall
Old 01-03-11, 06:40 PM
Join Date: Dec 2004
Location: San Jose,Ca
Posts: 1,277
Upvotes: 0
Received 3 Upvotes on 3 Posts
The furnace has power to it. It is called a "self generating", or a millivolt system. The pilot may be dirty and not generating enough millivolts to open the valve. Will the burner come on when the two wires are connected? If yes, buy "Millivolt" thermostat. If no, that leads me to suspect the pilot generator is either dirty, failing, poor splice in the wiring or a loose connection. If your utility co makes service calls, give them a call. If you would care to take pictures of the pilot and controls, we would be able to tell you more me thinks.
Ooooold floor furnaces tend to use 4 controls: thermostat, pilot generator, gas valve and regulator. Most are General Control parts.

The battery is increasing the voltage going to the valve and overriding which is why the burner came on. An old millivolt system probably has a PG-1 or even a PG-9 if it has been replaced.
Old 01-04-11, 10:48 AM
SeattlePioneer's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Jul 2007
Location: Seattle, Wa
Posts: 4,469
Upvotes: 0
Received 1 Upvote on 1 Post
Mbk3 is right.

Old floor furnaces are usually MANY decades old.

My suggestion ---- have a good repairman inspect and repair the equipment and service and maintain the heater. There can be safety hazards with this equipment.

Once you know it's in good condition, you can keep using it.

I'd pull up the grate at the floor level and remove the baffle below that circulates air around the hot heat exchanger. Usually these areas are plugged up with dirt and dust. Vacuum and brush it out and you will have a good piece of equipment.

DIY on old equipment like this will PROBABLY ignore safety hazards that a DIYer wont recognize or check for. The result is that an unsafe equipment that isn;t operating will be made into an unsafe equipment that is operating and is an actual hazard to people in the dwelling.

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: