Furnace will not turn on

Justrelaxing

I was replacing thermostat. So I turned main power off. Could not get it to work so wired old one back. I turned on main circuit breaker and furnace will not turn on. I have a luxaire furnace. I tried to look for reset on furnace but not luck. Any tips to try something?

Jamie Hall

First thing to do is to double check the wiring to the thermostat. Again, because I'm sure you did when you did it.

Justrelaxing

Thinking I will have to do that again...I do know they are in right spots..I can see from picture. Maybe they are somehow not seeded correctly....would that cause the furnace not to turn on? Since I cant really tell which breaker is for the thermostat...is it ok turning main breaker off as guessing I need power off when moving thermostat wires

DZoro

You probably blew up the fuse in the furnace. Change it out with the exact same one.
D

Intplm.

if you can, jump out the wires and listen to see if the thing turns on ?

Justrelaxing

I will go buy a fuse and replace.....Intplm...not sure what you mean...can you further explain?

HVACNUT

Get a flashlight. In the furnace, probably in the blower compartment there will be a circuit board. There might be a plug in fuse in the board. Like a car fuse. If not, check for an inline fuse after the transformer 24 volt side.

The thermostat is on the same breaker as the furnace. No need to shut off the main.

Question: How long did you wait to see if it came on? Some have a time delay of 5 minutes.
Also what thermostat did you install? Maybe it was DOA and something shorted.
Is it thermostat wire, or romex (house wire)?

Justrelaxing

I am planning on getting a fuse here shortly. Nice to know the thermostat is on the furnace circuit. I have waited 20 mins and nothing. Even tried the light switch on the furnace. The new one didn't work at all. It might have blown the fuse prior. I will get a few extra ones. I went without heat for the night. Dropped to 52, so very chilly this morning. There was a blue wire I noticed after a bit. So I hooked that up to the C spot and I did have to do that on the furnace board and I hooked that up to the same spot as the white ground spot. The fuse might have been blown prior if that is the case.

DZoro

C must go to C, W must go to W, You cannot interchange those! In this case White is not ground. W (white) is a heating signal, no wires can touch each other.
D

JUGHNE

Not all boards have fuses for their protection, most but not all.
Sometimes the 24 volt transformer just burns out.
It sounds like you may be crossing the common and the 24 volts hot somewhere with your connections.

It might be time to call a pro for repairs.

Justrelaxing

There was a white already attached to the C spot on the furnace board. On the spot where the thermostat is I have white to W. On furnace board white is also on w...that's why I thought the thin white on C was ground. Adding the blue common wire is the only thing I did to furnace

Intplm.

I'm asking if you can jump the wires to turn the system on? Splice two wires together? The furnace should fire up. How many wires and what thermostat do you have, what t-stat did you have?
How many wires do you have to the thermostat?

Justrelaxing

This white is from a thicker white wire which has a red wire also and that's connected to the yellow terminal

Intplm.

If you have just the 2 wires you should be able to twist them together and the unit should turn on. Then you you can trouble shoot from there.

JUGHNE

Do you see the 3 amp fuse on the board?
The "3" is upside down looking like "E".

Justrelaxing

Just bought 3 amp fuses....will be heading home to plug that in and hope....yes...I did twist the white and blue when trying new thermostat but didn't work. So I slide the blue wire threw when I went back to old thermostat. Should know in an hour if that fuse was my issue

JUGHNE

Also are you aware of the safety door switch on the blower compartment? Easy to overlook....no power with door off.

Justrelaxing

I did notice that after a few attempts after wiring the themostat.....can that short anything

JUGHNE

The door switch is just another power supply disconnect to keep you from running the furnace with the blower door removed which could pull CO from the fire into your house.

Its position of on or off should not affect the fuse.
Have you pulled the fuse out...you can see the small wire inside of it...it should be continuous and unbroken. Not always a positive check...but if "open" is blown.

Justrelaxing

The fuse was blown...replaced it and turned the circuit breaker on. I put the bottom panel back on and when I turn the light switch on the furnace on, I saw a quick flicker and furnace is not on.....a y other idea?

Justrelaxing

It blew the fuse. Going to try without the blue wire connected so it should be like it was prior to me messing with it

Justrelaxing

The furnace is on....thanks for everyone's help....really not sure why the blue wire would have caused that...

Alan (California Radiant) Forbes

The quick flicker could have been the fuse blowing again. Check the fuse and if it's blown, something has shorted; either by you or just a coincidence when you replaced the thermostat, probably the former.

At this point, I'd say it's time to call a service technician.

Justrelaxing

The flicker was the fuse. It blew...I took the blue wire off that I was using off and replaced the fuse and it all works....I will not mess around now as cold... I will talk to the electricians at work later this week and see what would have been the issue