furnace blower not turning on when in "on" position

Bushmonkey · #1 08-01-2017, 12:31 PM

Got a new HE furnace a year ago.

-blower will turn on automatically when the heat is on and the fan is in "auto" mode.

-with heat turned off and blower turned to "on", blower does not work.

-blower used to work when in "on" and the heat turned off.

I replaced the thermostat and it does the same thing.

I checked the wiring and its all secure.

We don't have AC.

Any ideas?

dewalt18 · #2 08-01-2017, 12:50 PM

Confirm that the G terminal is wired at bothe the thermostat and the furnace board. Also confirm that power is on to the furnace at both the wall or curling switch, and the breaker. Seems obvious, but you'd be amazed at the number of service calls. . .

Alberta bull hunter · #3 08-01-2017, 01:51 PM

I just fixed this exact same problem with the help of an electrician friend the other day, also in HE furnace. The relay was burnt out, new relay for 25 bucks and a guy who knew where to find the proper relay and it was that easy.

Bushmonkey · #4 08-01-2017, 03:44 PM

Quote:

Originally Posted by dewalt18

Confirm that the G terminal is wired at bothe the thermostat and the furnace board. Also confirm that power is on to the furnace at both the wall or curling switch, and the breaker. Seems obvious, but you'd be amazed at the number of service calls. . .

Doubled checked all these and they are good.

Bushmonkey · #5 08-01-2017, 03:45 PM

Quote:

Originally Posted by Alberta bull hunter

I just fixed this exact same problem with the help of an electrician friend the other day, also in HE furnace. The relay was burnt out, new relay for 25 bucks and a guy who knew where to find the proper relay and it was that easy.

I'll see if I can figure out which relay is for the blower

I'll see if the diagrams on the furnace access door show anything.

dewalt18 · #6 08-01-2017, 04:10 PM

I'll second the likelyhood of the relay. Depending on male and model, you may be noble to replace just the relay, otherwise could be a board replacement

Also, and a bit of a long shot, there are different leads to the motor for heating, cooling, and continuous blower. If they played around with these at install, there's a possibility that there is no wire attached to the summer fan terminal. Should be able to trace it back with the schematic on the door

Bushmonkey · #7 08-01-2017, 04:33 PM

Quote:

Originally Posted by dewalt18

I'll second the likelyhood of the relay. Depending on male and model, you may be noble to replace just the relay, otherwise could be a board replacement

Also, and a bit of a long shot, there are different leads to the motor for heating, cooling, and continuous blower. If they played around with these at install, there's a possibility that there is no wire attached to the summer fan terminal. Should be able to trace it back with the schematic on the door

I doubt this would be the problem because the summer fan as you call it has worked for months with no problem.

mgvande · #8 08-01-2017, 04:45 PM

You're lucky mine went when it was -40.

Bushmonkey · #9 08-01-2017, 04:56 PM

I don't think I can pull the relay's off this circuit board.

I don't want to yank them too hard, but I am guessing this this circuit board might be made so that the whole board needs to be replaced instead of the relay switch. Would this be the case?

If this is true, I'm pretty sure I can jump the fan to run all the time. Fan is G, what would I jump it too R or W?

dewalt18 · #10 08-01-2017, 07:15 PM

Fan on jumper r to g
W is heating

Y is cooling

If you don't have any a/c equipment attached, take the wire off of g and put it on y terminal on the furnace, should turn the fan on so you can control it through the fan switch on the furnace

Bushmonkey · #11 08-01-2017, 08:20 PM

Quote:

Originally Posted by dewalt18

Fan on jumper r to g
W is heating

Y is cooling

If you don't have any a/c equipment attached, take the wire off of g and put it on y terminal on the furnace, should turn the fan on so you can control it through the fan switch on the furnace

Awesome, thank you!

Bushmonkey · #12 08-01-2017, 08:23 PM

Quote:

Originally Posted by dewalt18

Fan on jumper r to g
W is heating

Y is cooling

If you don't have any a/c equipment attached, take the wire off of g and put it on y terminal on the furnace, should turn the fan on so you can control it through the fan switch on the furnace

I should ask..

So fan wire on mine is green. Just put it on Y? Do I need to jump anything as well?

Or is the blower on AC use a different relay?

dewalt18 · #13 08-01-2017, 08:55 PM

Color is irrelevant. The say wore should go from t stat to board on G terminal. At the terminal strip on the furnace, take it off G and put it on Y.

Put the lower door on and see if the fan comes on.

Bushmonkey · #14 08-01-2017, 09:04 PM

Quote:

Originally Posted by dewalt18

Color is irrelevant. The say wore should go from t stat to board on G terminal. At the terminal strip on the furnace, take it off G and put it on Y.

Put the lower door on and see if the fan comes on.

Yes sorry I meant G, not green..

I will try it and let you know

Bushmonkey · #15 08-01-2017, 09:21 PM

wire from G on thermostat is on Y2 on the terminal strip in the furnace. Blower wont work when in "on". I have no Y, just Y1 and Y2. There is no screw in the Y1 position, so I assume Y2 is what would be the Y you are referring to.

I turned the heat on to see if it still works and it does. Blower works when heat is on as well.

dewalt18 · #16 08-01-2017, 09:29 PM

Pull the screw from Y2 and put it on Y1, then put the wire from g to it.

You have a good mid to high end unit obviously, as Y2 is terminal for second stage cooling

Bushmonkey · #17 08-01-2017, 09:41 PM

Quote:

Originally Posted by dewalt18

Pull the screw from Y2 and put it on Y1, then put the wire from g to it.

You have a good mid to high end unit obviously, as Y2 is terminal for second stage cooling

I cant move the screw. By screw I meant the piece that holds the wire and the screw..

The Y2 is part of a one peice strip that has G, W etc.. All one piece.

If I jump G to R will it not run the fan constantly?

dewalt18 · #18 08-01-2017, 09:49 PM

Quote:

Originally Posted by Bushmonkey

I don't think I can pull the relay's off this circuit board.

I don't want to yank them too hard, but I am guessing this this circuit board might be made so that the whole board needs to be replaced instead of the relay switch. Would this be the case?

If this is true, I'm pretty sure I can jump the fan to run all the time. Fan is G, what would I jump it too R or W?

Quote:

Originally Posted by Bushmonkey

I cant move the screw. By screw I meant the piece that holds the wire and the screw..

The Y2 is part of a one peice strip that has G, W etc.. All one piece.

If I jump G to R will it not run the fan constantly?

Yes, it should. That's what I intended in post #10. A jumper between R & G should turn on the blower.

Bushmonkey · #19 08-01-2017, 09:53 PM

Quote:

Originally Posted by dewalt18

Yes, it should. That's what I intended in post #10. A jumper between R & G should turn on the blower.

I will just do this then.

Thanks again

Bushmonkey · #20 08-01-2017, 10:03 PM

Quote:

Originally Posted by dewalt18

Yes, it should. That's what I intended in post #10. A jumper between R & G should turn on the blower.

Blower is working now. Can't turn it off, but I didn't intend to turn it off regardless.

I have to talk to the guy who installed it in a few weeks, I'll ask him if the relays can be pulled from the board or if the whole board has to be replaced.

dewalt18 · #21 08-02-2017, 09:43 AM

If you're worried about being able to control it from the stat, switch the wire from the G terminal to the Y terminal on the control board. What this will do is turn on the blower in cooling mode. As you don't have a/c on the system, it won't make any difference to the furnace