Hello-

I have recently purchased a Lennox Elite G50 DF furnace. It ran great for about two months, then the 3 amp fuse on the circuit board tripped.

Service tech indicated it may be the thermostat or the wiring from the thermostat to the furnace.

I changed the thermostat- but had the same issue.

I would like to change the transformer (10 VA Class 2)(pictures attached) before moving on to re-wiring, but I am having trouble finding the transformer.

Does changing the transformer seem like a good thing to try first? And if so, where would I find the part?

Thanks,

S

As long as the transformer is still putting out the 24 volts, I wouldn't change it. You need to track down the over load that is blowing the fuse.

I don't like the looks of the installation. Usually the transformer is mounted by the holes in its base inside the furnace at the factory. What is the little box under it, the fuse holder?

When does the fuse blow? Early in a heating cycle? I would disconnect the wires to the thermostat and run a few heating cycles jumpering the red and white wires. When you do that, the furnace should come on and run until you break the connection. If the furnace will run with them jumpered without blowing the fuse, the problem is in the wiring to the thermostat. You will have to pull in a new cable if the problem isn't out where you can fine it. If the furnace is in an unfinished basement, a new cable shouldn't be that hard.

Thank you for the information.

Yes, the box does hold the fuse. I have included a picture of the set-up because you mentioned this may be less than an optimal way to set up the system. Does this set-up look wrong?

You also asked when the breaker trips- it occurs immediately.

Finally, you mentioned I could jumper the wires to see if the breaker trips again. Are the wires to jump the ones leading from the transformer to the furnace or the ones running from the thermostat to the fuse box? Or am I just totally confused :confused:

Thanks,

S

That transformer does not belong connected to your new furnace. The new furnace has its own transformer.