[jeepgrady]

Carrier infinity dual fuel, 3 years old, no heat. Led code 24, according to manual= secondary voltage fuse is open. Check for: short circuit in secondary voltage wiring. Dealer wants $225., just to walk in the door since it's after hours. Have him coming tomorrow instead. Broke out the electric heaters.

Any ideas?

 

[DOUG1111]

fuse may be on your control board?? 3 or 5 amp? What do you think caused the problem?? secondary voltage is 24 VAC - read more post on this site -- pics??

 

[jeepgrady]

Found my 3a fuse on furnace board was shot. Replaced it. So far so good
Obviously, if it goes again, I will get service.
As far as what caused it to go bad, no idea. I didn't touch anything prior to noticing no heat. Thanks for your help.

 

[DOUG1111]

Found my 3a fuse on furnace board was shot. Replaced it. So far so good
Obviously, if it goes again, I will get service.
As far as what caused it to go bad, no idea. I didn't touch anything prior to noticing no heat. Thanks for your help.

That 3 amp fuse protects the 24VAC side- T/S wires //// check for a bare wire where the wires go into the furnace/ short to ground/ metal cabnet. Best of luck!!

 

[jeepgrady]

Furnace has been running fine since replacing the fuse. Looed for bare wires. Couldn't see anything out of the ordinary. Could the fuse have just been week?

 

[HVACDave]

Possible, but unlikely, could be a multitude of things in the low voltage side as simple as a clip or staple holding the t-stat wire against the ductwork or other bonded/grounded material like the gas piping or air conditioning lines, a loose connection to the board that vibrates when the fan is running or a wire pinched in the door frame of the unit etc.

 

[jeepgrady]

Fuse blew again. I don't see anything that is an obvious problem. While I was in the furnace room with the furnace running, I heard a loud clicking which appeared to come from my Honeywell humidifier solenoid. Based on my control board where the humidifier is wired to, the humidifier was energized and I could see that water was discharging from the bottom. Question: could the clicking solenoid be the problem?

 

[beenthere]

Only if the humidifier is using the furnace's transformer. Many don't.

Every once in a while, the RV's coil will begin to short out, and blow a fuse intermittently. Same can happen to the coil of the heat pump.

 

[jeepgrady]

Heat ran fine throughout the night. Had the tech out this morning since I couldn't find anything obvious. Checked everything indoors. Didn't find anything. HE found the problem within my outside unit. There was a wire laying barely rubbing one of the interior copper pipes. There was a minute area where the wire was bare from rubbing. Taped it up and moved the wire away.

Thank you for your replies.