Garage Gas Furnace=No go


Old 11-05-05, 10:27 AM
Visiting Guest
Posts: n/a
Garage Gas Furnace=No go

Good Day;

Grinell Excello Gas Forced Air Garage Hot Air Furnace.

I've just installed the gas line to the garage with the assitance of my wonderful assitant (my wife). I've hung the used Excello from the ceiling. Installed the Bvent chimeny as per code.

I can get the pilot light lit and I have 120 to the transformer and circuitry. I must be missing something because the unit wont fire. I could have the circuitry incorrect but I haven't been able to find a source on the net to confirm the wirering.

I have a thermostat wire hooked into the transformer curcuit. When I cross the thermostat wire I get a humming but after 20 seconds it stops.

The fan doesn't come on and the burner is refusing to fire.

I have replaced the thermocouple with no success.

I would greatly appreciate any and all help as winter is arriving here in central Alberta. I'm trying to get my garage turned into a shop so that I can accomplish so many of the projects that I have been unable to do in the summer.



Rob in Alberta
Sponsored Links
Old 11-05-05, 05:52 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 13,936
Received 1 Vote on 1 Post
Pilot only

It could be as simple as having the gas valve still on "pilot" instead of "on". When the thermosat is calling for heat, do you get 24 volts to the gas valve?
If you do, you could have a bad gas valve. Has anyone checked the gas pressure to be sure it is within the furnace manufacturer's specs?
Old 11-05-05, 06:51 PM
Join Date: Dec 2004
Location: San Jose,Ca
Posts: 1,561
Received 0 Votes on 0 Posts
Is this a new unit? If so did you use existing make up box or try to wire yourself? You shouldn't have to do anything more then connect supply voltage & run low voltage wires. What are we missing?
Old 11-05-05, 09:09 PM
Visiting Guest
Posts: n/a
Garage Gas Furnace= No Go

What are we missing?

I'm new to furnaces in regards to installing them. But I did install the gas line from the house to the detached garage. Thread all the pipe and pressure test the line. When it gets to the electrical of it all this is where I'm not so certain...

The unit is a used one and I'm not certain of the age but I'm guessing at least 15 years (for $60 I'm thinkin it was a fair trade, if it works).

I've been able to figure out the manifold to the "set, pilot, on, off" level.

The wirering was in place except for the thermostat wirering. When I shorted the thermostat wires the manifold would hum for about 20 seconds. I thought that this was calling for gas but not providing it. Then the huming would stop. I'm certain that the heat exchanger is to heat up before the fan comes on.
As mentioned I changed the thermocouple as it was possible that it wasnt' working. Then after a few attempts I tapped the manifold to possibly loosen a stuck valve. No luck.

The transformer... is it giving 24 volts?, good question. I wired the thermostat wirering and I'm getting milli volts through that wire. I'll check directly off of the transformer.

Would anyone have a wirering diagram that may be helpful for me?

Again any and all input is appreciated.


Chilly Rob in Alberta

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

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