Can't get heater to fire? Please help?

AlaskaHeat

I live in Alaska, we are having negative temps. My inducer motor went out (wouldn't spin and was super hot to the touch when I found it) I replaced it. Now the pilot will stay lit, and the inducer kicks in. But the heater will not fire. I live in an older mobile home and the furnace is a Coleman presidential 2. Any help would be awesome, I cant afford to have an HVAC tech come in...

AlaskaHeat

Forgot to mention, tested the upper limit switch and it read 0 ohms, replaced the relay and all but one wire (the wire to the White t-stat)

Big Ed_4

Connected to the housing of the draft inducer there would be a rubber house connected to an pressure switch . The switch sensors if the inducer is doing its job and turn on the burner . Is the switch closing .. Check condition of hose and blockage of connection into the housing ...

AlaskaHeat

This doesn't have a pressure switch near the inducer...

Zman

Can you post a picture of what you have?

AlaskaHeat

Here is the inducer and gas valve, and the heater model. I have q couple more if needed.

AlaskaHeat

Also here is how its wired in.

Motor
Black- Terminal #5 on relay
Black- polarized plug on 115v box
Blue- gas valve
White- Terminal #3 on relay
Red- capped with wire nut


Relay
#1- thermostat and gas valve
#2- no connection
#3- white from motor and green/blue on transformer
#4- polarized plug on 115v box and White/yellow wire to transformer
#5- Black on transformer and black from motor

If I need to rewire that can be done.

Thanks in advance

EBEBRATT-Ed

There must be a transformer to change 120 volts to 24 volts somewhere. There also should be something in the safety circuit to power the gas valve and prove that the burner motor is running perhaps an air switch or a centrifugal switch. Did the old motor you took out have anything else mounted on it?

Do you have any extra wires not connected?

HVACNUT

What are you calling the inducer? The burner motor?
Have you checked for 24v at the relay coil and gas valve?
Is there a centrifugal switch on the motor?
Is there a legible wiring diagram you can post?

AlaskaHeat

@EBEBRATT-Ed
>
> Do you have any extra wires not connected?

There are 2 Red wire capped with wire nuts. One from the motor (near the pilot not the big blower) and the other from the transformer on the back of the control box.
> @EBEBRATT-Ed said: Did the old motor you took out have anything else mounted on it?

No it didn't have anything else mounted on it.



> @HVACNUT said:
> What are you calling the inducer? The burner motor?
The small motor near the pilot. Part# S1-8680-4329
> Have you checked for 24v at the relay coil and gas valve? Have not... Not sure how. I do have a analog multimeter. Forgive my ignorance

> Is there a centrifugal switch on the motor? Don't think so.

> Is there a legible wiring diagram you can post? Here are the diagrams I found....

Jolly Bodger

First thing, is the gas valve turned to ON and not Pilot?
If so with the thermostat calling and the burner motor running start checking for 24VAC at the gas valve.

AlaskaHeat

Yes, the gas valve is set to on. Will check shortly if 24vac when the thermostat is calling

Big Ed_4

Is the pilot lit, it looks like there is a button to activate a glow coil to light the pilot , If ,if it still works and if you can get it lit is the thermalcoulping still good .

AlaskaHeat

.

> @Big Ed_4 said:
> Is the pilot lit, it looks like there is a button to activate a glow coil to light the pilot , If ,if it still works and if you can get it lit is the thermalcoulping still good .

Yes the pilot is lit did replace the thermocouple because I had an extra laying around.

> @Jolly Bodger said:
> First thing, is the gas valve turned to ON and not Pilot?
> If so with the thermostat calling and the burner motor running start checking for 24VAC at the gas valve.
Tested at the gas valve and at the relay #1 and #3 0 VAC, the meter didn't move

mattmia2

if the pilot is staying lit the thermocouple was good

But it isn't clear to me how it verifies that blower is running before opening the gas valve.

Jolly Bodger

I don't think it does verify the blower is running.
If you have 0-VAC across the relay coil #1 and #3 if wired correctly, and the burner motor is running. then something is not wired correctly.
Relays do not have universal terminal #s. You have to read each relay and wire it to purpose of the terminal.
Judging from the first picture of the gas valve and burner, it appears that one of the wires from the gas valve is dead ended.

AlaskaHeat

> @Jolly Bodger said:
> I don't think it does verify the blower is running.
> If you have 0-VAC across the relay coil #1 and #3 if wired correctly, and the burner motor is running. then something is not wired correctly.
> Relays do not have universal terminal #s. You have to read each relay and wire it to purpose of the terminal.
> Judging from the first picture of the gas valve and burner, it appears that one of the wires from the gas valve is dead ended.

The gas valve has 2 wires... Both tan/yellow, one is going to the blue wire from the motor, and the other is going to terminal #1 on the relay.

Jolly Bodger

If I read your earlier post the motor has 5 wires? 2 black, 1-blue, 1-white, 1-red. the black wires power the motor, that appears to be working correctly. The other 3 are the centrifugal switch that prove the motor is running. One is the common wire, one is a normally closed terminal. one is a normally open terminal. You will need to OHM them out to figure out which is which. Then make sure that the circuit is wired so the input from the thermostat goes into the common terminal, and the Normally Open goes out to the gas valve. The other wire from the gas valve returns to the transformer.

AlaskaHeat

Here is the old and new motor and relay.

SuperTech

Red and White are the centrifugal switch that proves that the motor is running. Check for continuity between those wires as the motor is running.

HVACNUT

> @SuperTech said:
> Red and White are the centrifugal switch that proves that the motor is running. Check for continuity between those wires as the motor is running.

White and Blue are the N.O. contacts on the centrifugal switch.

SuperTech

> @HVACNUT said:
> > @SuperTech said:
> > Red and White are the centrifugal switch that proves that the motor is running. Check for continuity between those wires as the motor is running.
>
> White and Blue are the N.O. contacts on the centrifugal switch.

Lol, yes they are. My mistake. Red and White open when the fan runs, white and blue close as it runs. My mistake

Jolly Bodger

From what I can see here you have it wired correctly.
Verify these conditions:
Thermostat not calling (off)= burner motor not running
Thermostat calling (on) = burner motor running
With thermostat calling you can measure 24VAC across #1-#3 on the relay.
Check continuity between motor centrifugal switch leads. White to Blue should be open when the motor is not running and closed when running. White to red should be Closed when not running and Open when running.

icy78

Hmmm
On the last pic, it appears you have wires on ? and 5.
Probably should be on 2 and 4. Those contacts make, upon energizing of the relay.

AlaskaHeat

> @Jolly Bodger said:
> From what I can see here you have it wired correctly.
> Verify these conditions:
> Thermostat not calling (off)= burner motor not running
> Thermostat calling (on) = burner motor running
> With thermostat calling you can measure 24VAC across #1-#3 on the relay.

I am getting 0vac across 1 and 3.
Should also mention we are having negative temps currently, to get the motor to run/not run I have to hit the service switch to cut power,otherwise the motor runs all the time. When it was a bit warmer it t-stat would click engaging the motor.

> Check continuity between motor centrifugal switch leads. White to Blue should be open when the motor is not running and closed when running.

White and blue are reading 0ohms with the motor running and 0 with out it running


>White to red should be Closed when not running and Open when running.

Red wire from the motor is wire nutted off



> @icy78 said:
> Hmmm
> On the last pic, it appears you have wires on ? and 5.
> Probably should be on 2 and 4. Those contacts make, upon energizing of the relay.

Relay wiring is

#1 white t-stat plus gas valve
#2 no connection
#3 white from motor and green from transformer
#4 yellow/white from transformer
#5. Black from motor and black from transformer

Jolly Bodger

The motor runs all the time, correct?

@icy78 is right, #5 should have no connection on it.

The black wires from the motor should be:
One to #2 on relay
One to 120 VAC coming in from the polarized plug (this connection may be at the transformer.
The other wire coming in from the polarized plug should be connected to #4 on the relay and the other side of the transformer.

Jolly Bodger

Adding two returns between quotes and responses would help.

AlaskaHeat

> @Jolly Bodger said:
> The motor runs all the time, correct?
>
Yes the motor is running all the time unless I kill the service switch. (The little on/off light switch near the polarized plug


> @icy78 is right, #5 should have no connection on it.
>
> The black wires from the motor should be:
> One to #2 on relay
> One to 120 VAC coming in from the polarized plug (this connection may be at the transformer.
> The other wire coming in from the polarized plug should be connected to #4 on the relay and the other side of the transformer.


I can double check these at lunch... Stuck on a 12hr shift today

Jolly Bodger

I think you have two wiring issues. One the motor on #5 instead of #2. And it appears the transformer is not powered correctly. The White and Black on the transformer need to be powered all the time from the plug.

Then the motor should turn on and off with the thermostat and you should be able to measure 24VAC across the thermostat terminals.

icy78

Where are you in Alaska? Just interested.
I lived in Wasilla for 7 years and Kodiak and Dutch harbor for 12. Well, not really living in Dutch, but based out of there.
I'm down south now tho . Lower 48.
What are you heating with, this past week?

AlaskaHeat

> @Jolly Bodger said:
> I think you have two wiring issues. One the motor on #5 instead of #2. And it appears the transformer is not powered correctly. The White and Black on the transformer need to be powered all the time from the plug.
>
> Then the motor should turn on and off with the thermostat and you should be able to measure 24VAC across the thermostat terminals.

If I put the motor on #2 it clicks rapidly and doesn't spin the motor.

The transformer is wired as follows

(Upper)Yellow on transformer to Red on t-stat
(Upper)Green on transformer to white on motor and #3 on relay

(Lower) black on transformer to polarized and #4 on relay
(Lower) White/yellow to black on motor and #5

Jolly Bodger

Yeah, your transformer needs to be wired hot all the time. The wires from the plug need to go to the transformer.

the black wire is fine. White wire needs to got to the other wire of the plug.

Jamie Hall

I'd really like to help, but I'm confused at this point.

Can you draw a diagram of the wires (I don't care what colour they are; electricity is colour-blind) showing exactly what they connect to at each location or device? And for the relay and motor, a commentary on exactly what each terminal is supposed to be? such as for the relay, the two coil terminals and the normally open and normally closed contacts and the common, if there is one? And for the motor power and the normally open and normally closed outputs and the common on the centrifugal switch? Then I may be able to make some intelligent comments...

JUGHNE

Jamie, I think they are close to solving the problem.....maybe.

AlaskaHeat

> @icy78 said:
> Where are you in Alaska? Just interested.
> I lived in Wasilla for 7 years and Kodiak and Dutch harbor for 12. Well, not really living in Dutch, but based out of there.
> I'm down south now tho . Lower 48.
> What are you heating with, this past week?

Living in Anchorage, mostly the wife and dogs are hanging out at the neighbors place. I'm stuck at work most the time.

Also, I will be home in about an hour to move more wires and see where that gets me.

Thanks in advance for all the help

AlaskaHeat

> @Jolly Bodger said:
> Yeah, your transformer needs to be wired hot all the time. The wires from the plug need to go to the transformer.
>
> the black wire is fine. White wire needs to got to the other wire of the plug.


Moved wire to other side of polarized, and just went click, then moved #5 to #2 and its firing.

Now it's seeming to run short blow cycles? Waiting a little while to see what happens.

AlaskaHeat

So far, ran for time #1, stopped blowing and just the inducer was running for time #2, and ran again at time #3.... Possible the heater needs to warm up?

AlaskaHeat

> @Jolly Bodger said:
> Yeah, your transformer needs to be wired hot all the time. The wires from the plug need to go to the transformer.
>
> the black wire is fine. White wire needs to got to the other wire of the plug.

THANK YOU!!! And everyone on here who commented! Gladly, I am just an idiot and wired it wrong.

Jolly Bodger

So it is working now? or is it short cycling?

There are a lot of wires crammed into the box and if you don't know what they should be doing it is easy to get things switched around. In this case you have 24 volt and 120 volt circuits. It is lucky you didn't cross the two.

This is why we often say if you don't know what you are doing, put your hands in your pockets and call a pro.

Glad you have heat now!

HVACNUT

Glad you got it working but the furnace is from 1987 so start saving. The heat exchanger won't last forever.

mattmia2

In fact it definitely should be looked at by a professional to check the heat exchanger and make sure the combustion is adjusted properly, especially since it is a power burner.