Bryant Furnace will not Light

I have a Bryant furnace that is about 15 years old. It does not have a standbye pilot. It has the electric pilot. There is no power at the thermostat and when trying to hotstart it the furnace by making a circuit with the thermostat wire near the boiler produces nothing. I have two identical Bryant furnaces that work fine (3 family house). What could be wrong?

 

How are you going about this hot starting method? Are you making the right contacts down in the boiler? You have to bridge the 24 volt (red wire) outgoing TO the thermostat TERMINAL to the white return wire (FROM the thermostat) TERMINAL. Are you doing that? Or are you just twisting wires together down there? Have you actually tested to see if the red wire terminal has 24 volts to ground, at that terminal? If you don't have 24 volts there, you had better check to see if you even have it at the outgoing two wires of your transformer. But even before doing THIS, I hope you confirm that you have 110 volts coming into your furnace from the fuse or breaker, and that the switch is on at the furnace, if you have one.

 

The furnace has power. I am just touching together the two wire that connects to the thermostat. When this is done, the automatic vent damper opens but I don't hear the clicking sound of the electric sparker or the gas valve open. I can touch together the thermostat wire on the other two boilers and the auto vent damper opens, it starts sparking and the gas valve opens and the boiler then fires.

What is causing the boiler to fail?

 

You need a multi meter to check for voltage.

 

I checked and have 110v coming in and it stepped down 24v.

 

It still is not clear from your posts, where you are joining the thermostat wires together at, for the other furnaces you can get to work, this way. If you disconnected wires in the furnace to touch wires together, nothing should happen. But, if you removed a thermostat and touched the wires together, you would then complete the circuit.

Please explain EXACTLY what you have been doing. We have to know, positively, if you are getting 24 volts to go up to the thermostat.

But, the fact that thru your touching of the wires, you are getting the vent damper to open, means you are forcing it to sequence, so......hmmmm....

Do you have a vent damper motor air switch, that has 2 little 24 volt wires that go between it and the vent damper motor area and also have 1 or 2 vacuum tubes that go between the vent and the vent damper motor air switch? If this switch (if you have one) gets stuck, and is not "closed" (does not let 24 volts pass thru the 2 terminals), then the ignition process cannot begin.

(I happen to have this very thing going on right now, myself, in a rental I own. The problem seems to be in the air switch, and I have been able to get the furnace to go by blowing and sucking on the vacuum tubes. And then I rehook up the vacuum tubes and run the furnace and see. It could be a case of a bad diaphram - but I sort of doubt it as it seems to hold air - or, more likely perhaps some corrosion in the internal contacts due to acidic moisture, perhaps. The motor appears to be pulling a vacuum okay, as everytime I run the furnace I can actually hear the sound of the contact being made. But yet, only sometimes does the contact allow the passage of the 24 volts. If this sporadic malfunction keeps it up, I will probably spring for a new air switch and see what happens.)

Anyway,this should be a start for you.