How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask BillyHvac Your Own Question
BillyHvac
BillyHvac, Journeyman HVAC Tech
Category: HVAC
Satisfied Customers: 22116
Experience:  Endorsed for unlimited heating, cooling, oil burners, boilers, refrigeration, hydronics
12672042
Type Your HVAC Question Here...
BillyHvac is online now
A new question is answered every 9 seconds

We have a G1N80bt armstrong heater that won't ignite. We

Customer Question

We have a G1N80bt armstrong heater that won't ignite . We have 3 flashes on the led. The induction motor turns on, but the Igniter switch never glows. We've cleaned the port where the rubber tube connects to the motor, we've replaced the pressure switch, the door switch the Igniter and the flame sensor. Running out of ideas.
JA: I'll do all I can to help. How long have you been dealing with this?
Customer: Since this morning. The heater worked last night.
JA: Do you plan on doing the work yourself?
Customer: We have so far
JA: Anything else we should know to help you best?
Customer: Don't know
Submitted: 17 days ago.
Category: HVAC
Expert:  Gaztech replied 17 days ago.
  • With the hose connected to the pressure switches and unplugged at the other end lightly suck and push air with your mouth to see if you hear clicking in pressure switch, if air runs right through it, the diaphragm inside is ruptured, then replace press switches, sometimes water get inside them and they get stuck, after the sucking it may have released it and it will work after but still recommend to replace with new.
  • If the hose goes directly to the power venter, clean out the nipple end of power venter where hose connects with a small wire.
Customer: replied 17 days ago.
We already cleaned the nipper end and replaced the pressure switch after blowing air through it.
Expert:  Gaztech replied 17 days ago.

Remove power venter and inspect inside for damage

Expert:  Gaztech replied 17 days ago.

FYI. 3 flashes means pressure switch not closing.

Customer: replied 17 days ago.
We started with the pressure valve. Took the pressure ventor off. Doesn't appear damaged. The blades turn smoothly.
Expert:  Gaztech replied 17 days ago.

I will let another expert try to help you

Expert:  BillyHvac replied 17 days ago.

Does the exhaust motor run during this code?

Customer: replied 17 days ago.
it does
Expert:  BillyHvac replied 17 days ago.

and have you checked vent pipe/chimney for any blockage>

Customer: replied 17 days ago.
As near as we can tell, there is nothing blocking it.
Expert:  BillyHvac replied 17 days ago.

do you mind a short hands on test?

Customer: replied 17 days ago.
Sure
Expert:  BillyHvac replied 17 days ago.

do in this exact order:

power off

remove the 2 wires from pressure switch

hold wires apart

power on

AFTER the exhaust motor starts put the 2 wires directly together metal to metal and hold.

you may find a small nail or wire shaped in a U handy to insert into the wire connector ends.

Tell me if the ignitor starts.

Customer: replied 17 days ago.
Nope. As soon as the wires are connected, the motor turns off.
Expert:  BillyHvac replied 17 days ago.

as soon as the wires from the pressure switch connect the inducer shuts off?

Customer: replied 17 days ago.
Expert:  BillyHvac replied 17 days ago.

Does your induce motor wiring come from the gas valve?

Customer: replied 17 days ago.
No. The wiring goes to a metal box on the side of the heater and the power cord comes out the other side.
Expert:  BillyHvac replied 17 days ago.

Thank you. The only thing that interacts the pressure switch with 120v motor is the control board.

Can you get me the number from the control board or a pic?

Customer: replied 17 days ago.
Pic
Expert:  BillyHvac replied 17 days ago.

very bottom of board center/left is a small black button....with power on hold that button in for 5 sec.

put all wires back in place and tell me if same issue remains

Customer: replied 17 days ago.
Same problem.
Expert:  BillyHvac replied 17 days ago.

Thank you.

Then you have a bad circuit board.

The interaction between the 24v signals and 120v relays on the board are defective.

Only fix is new board.

Billy

Customer: replied 17 days ago.
Is the 47582 number the replacement #
Expert:  BillyHvac replied 17 days ago.

you can shop around with the model.

See Here

And HERE

Customer: replied 15 days ago.
replaced the circuit board and still doesn't work. Same three light flashing.
Expert:  BillyHvac replied 15 days ago.

Then one of the test prior was not done correctly when we bypassed the pressure switches.

Can you post a pic of the diagram on the back of the blower door?

Customer: replied 15 days ago.
This one?
Customer: replied 15 days ago.
Or this?
Expert:  BillyHvac replied 15 days ago.

ok,

on the back wall is a limit switch...flat against back wall...has a white wire on one side and a brown and violet on the other...the violet leads to pressure switch.

Do you see this violet wire

Keep this handy

Customer: replied 15 days ago.
OK, yes
Expert:  BillyHvac replied 15 days ago.

now the violet goes to the pressure switch and then out the other terminal...you will see where I drew arrows...that there are 2 "if used" switches.....can you tell me what the violet wire goes to before it goes back to circuit board or show pic of it?

Customer: replied 15 days ago.
I'm pretty sure that it goes here
Expert:  BillyHvac replied 15 days ago.

oh boy...a hidden auxillary limit...reach back there and press the center and see if it clicks

Customer: replied 15 days ago.
There is nothing in the middle to push.
Customer: replied 15 days ago.
There is another one on the other side side too.
Expert:  BillyHvac replied 15 days ago.

there is usually a bump plate over the switch.

remove the 2 wires....pull them out to where you can work on them.

Cut ends and twist together and tape. (this is a redundant limit if the unit were upside down...)

Can you try this now?

Expert:  BillyHvac replied 15 days ago.

you see the furnace is multipoise.....those are there to cover if you had the furnace horizontal or vertical downflow....I assume yours is a standard upflow?

Customer: replied 15 days ago.
Expert:  BillyHvac replied 15 days ago.

if 2 bypass both...we only need the one up above burner