adman77

Hi all

I have gas coming into this furnace.
This Furnace is old,maybe installed in 1982
Its about 80k btu

I had moved into the house, furnace worked great for 2 weeks, i did notice the pilot lit as well and hot air coming out.

Nothing was done to the house for this to stop.

after 2 weeks ,i kept hearing this click click and heard and felt the furnace come on and off, and again on and off within like seconds apart, it had done this several times.

After that,this is were i believe the pilot no longer lights and no hot air comes out.the furnace will not even come on when i have the thermostat set to auto.

Again, only when i set it to "on" thats when it blows out cold air.

So, this is where i stand.

The previous contractor came out and replaced both the circuit boards and still same thing is happening.

I even reset my thermostat just in case and shut the power off to furnace for 10 minutes.

If anyone else would know what could be the exact issue, i am all ears and willing to try anything

Thanks

JohnH1

So a company came out and replaiced the boards and this did not correct the problem. What did they say? I assume the just sead I don't know and walked away.
Anywat lets start with the basics. Is the furnace draft indused? IE does it have a little fan that connects to the flu pipe and if so does it start upon a call for heat.

hvaclover

It's the three wire pilot assembly.

__________________
Just slow, not stupid.

HvacWiz

Bingo

hvaclover

:thum bup:

Thank you (bowing at waist deeply) thank you! Please! Just throw money.

__________________
Just slow, not stupid.

adman77

Hey Guys
Thanks for the help on this.

The blower is attached to the vent.
When i set the thermostat to auto , on high , for heat, the blower will not turn on or do anything, not even click on.Usually when i set it to something high, the furance would do some clickies then you hear the blower turn on and the pilot go.

When i set the thermostat to the on position, the blower will come on and only cold air comes out, because of no pilot lit.


As for the circuit boards, yes the contractor came out, looked at,scratched his head and thought to himself ( how much more $$ can i rip this guy off for ) .So, a couple of days later he returned with 2 circuit boards and puts them into the furnace, wires everything back up and tells me, he has no idea what else it could be because even with replacing the 2 circuit boards,its still doing the same thing.
He then comes back another day later with a buddy for a second pair of eyes and says ,they dont know.

And that was the end of it.


I believe he had also done a bunch of wire splicing to jump wires and things like that to override somethings.
but it all came down too, i think their is a leak in voltage somewhere or your furance is too old, buy a new one.

That was it.
Let me know what you guys think, im willing to try anything at this point.

I will even replace the 2 circuit boards myself because the contractor took by the new ones they tried.



Mike.

JohnH1

A leak in voltage! That one I havent heard of yet. Those guys are bone heads. You need to try another company. 1st step is upon a call for heat the draft induser should turn on. If it dosent you need to check for power at the induser and work your way backwards.
Actually start with jumping the R to W thermostat wires at the curcuit board on the furnace to see if the heat starts. Note: there is a blower door safety switch that needs to be depressed if the blower door is off.

adman77

Thanks John on that info

I will look into that.I wouldnt suppose to can show me or tell me where that inducer is located or if there is a part number on it?
Maybe even what wires are connected to it so i can locate it.

Also,you had mentioned to jump the R and W wire together to see if the heat starts.
Do you mean the Blower should come on as well as the pilot being lit for the heat?

because neither happens when thermostat is on auto.
No Pilot lit and no blower comes on.


Thanks again.

JohnH1

The induser is the little fan that is in the furnace and the chimney pipe hooks up to it.

kennzz05

you better hurry and mop up all that leaking votage before you track it on the new carpet HARDY HAR HAR

kennzz05

the induCer i think on that unit has a little chrome cage over a small black plastic cooling fan thats the first thing that should run when heat is turned up . on another note the auto and on switch on your tstat only controls the blower. auto means the blr runs when heat is heating and on means fan runs continuously

adman77

Hahahaha!

yea, the the contractors told me there was a leak or something in the wireing, i was thinking to myself ,now thats some BS.

I mean the Furnace ran fine for like 20 years and something just died or got worn out.
Even i know that and they knew that as well.
I was working on adding an adding an additional outlet down on the other side of the room, and he tells me that it maybe related to the wiring i have been doing in the house.

LMAO, i tell him, Nothing is even connected yet, wire is still dangling out of the switch box.!

Anyways.
Okay, so with the tstat on or auto, that just controls the blower.
Well, atleast the blower works!

I had tried to jump the wires on that inducer.Maybe im not jumping the wires the correct way,but nothing happens when i did that.

To jump the wires, i would just connect both wires together or keep them attached to the inducer and connect the wires with like a metal object ( screwdriver) while holding in the button from the door switch.

Let me know what else i can try or do.

Again thanks for your help, i really appreciate it.
This is like the only forum page that someone is actually helping me out on.

If it helps more, i can even take pictures of the inside of the furnace to review,if that helps.

JohnH1

No No No do not jump the induser wires!!!
Jump the (R) Red to (W) White thermostat wires at the curcuit board on the furnace down in the blower compartment to see if the heat starts. This simulates the thermostat calling for heat.

Dr Heat

voltage Leak Ha Ha well maybe

If you have been doing electrical work you may have reversed the polarity or dropped the neutral.

To a bone head (I like that ) it would look like leaking electric.

actually it does allot of weird things a dropped neutral that is

you will get strange readings like 96.2 volts or even 35v on the low volt side.

Reversed polarity screws up the ignition on some furnaces

adman77

You guys think i should try a seperate wire connecting from the circuit box directly to the furnace box?

To rule out this leak of any kind?

What do furnaces use anyways? 15amp 20?
12 gauge wire or 14?


Thanks