Trane xe80 no heat

tackman

Hello, I have a 10-11 year old Trane XE80 unit mounted horizontally in my attic. I replaced 'stat with a Honeywell 6110 sometime this past year and this is the first time I've had to fire up heat. (Cooling worked fine over the summer). I'm sure I wired it up right when I installed, but I'm getting no heat. Done alot of reading and here's where I'm at:

I unscrewed all 'stat wires from furnace board (left A/C compressor wires in place), jumped the red and black to fire heat. I get blower motor and 9 blinks - "Check Ignitor". So I pull the HSI where I can see it, fire up the routine again. I can see a bit of red but I don't think it's hot enough to fire gas. I am getting no gas smell between tries, but that may be indication that gas valve doesn't start until system verifies the ignitor is working???

So I figure it's worth a try given that the system gave me the check ignitor code. I have an, I think, obsolete Trane B340971 in it. My Trane dealer had an IGN00117 as the replacement. I haven't mounted it yet, but when I run the same test, jumping the R/W with the ignitor pulled out within view, I get the same 9 flash code. Will I have to mount it to get best test results?

Should I rehook the stat and test it completely reassembled?
Should I pull the flame sensor and clean it off while I'm in there?
Should I be able to mount new ignitor without pulling the whole venturi tube assembly?

Any other suggestions to look at before I have to make a call?

tackman

Update: new Ignitor, correctly mounted in-place not firing up either. I remove it from its bracket and view it and it gets no redder than previous. (OK, so I may have a good spare now). But what could be preventing ignitor from getting fully hot? Is there something in the system I can check that is preventing sufficient time or current for ignitor to be heating up?

Old voltmeter, see pic:



...will register about a 5 on the bottom scale when set on 250. While I'm not sure if I'm reading it right, I figure that's 5 out of 10 or 1/2 of 250 or about 120 volts being fed to the ignitor. But it only stays there for about 1.5 seconds and then power to it shuts off, the fan stays on and the 9-flash code comes on. So I think the correct current is getting to it, I just don't think that it's allowing it to stay on long enough.

Any ideas or help?

kenmac

Most furnaces get power for heat to come on from the white wire. You are saying yours is powered with lack wire ? at the control board. r w g y c

tackman

Sorry, mistyped that. I cross the red and white (hey I did get it right later with the R/W!)

kenmac

so did you check voltage ?? should get atleast 24v from w to c

tackman

I just did check it and I am getting 120v to the board on the line spades, and (again, I think,) better than 24 v from w to c. So is transformer working? Bad board (50A65-475)???

kenmac

If you are getting 110v where the ignitor connects to the board on a call for heat & ignitor doesn't glow. Then, ignitor is bad. If you don't have 110 where ignitor connects to board & all other functions are ok.then, board is bad

tackman

The 120v I said I was getting at the board was testing the Line-In hot and neutral.

I didn't test at the board where the ignitor plugs in during a call for heat. However I did test at the modular in-wire plug during call for heat and got 120v. So 120 must be leaving the board, but only for about a second and a half.

kenmac

I've never timed it. It must have 110 long enough to glow the ignitor up to temp

tackman

It's def not staying on long enough. Don't know what else to look at at this point besides blaming the board and I hate to make that assumption so fast.