HELP!! Furnace went out

[KBertetto]

And of course it went out when it was 39 degrees outside. Here's what's going on:



Blower motor will kick on and run like normal, ignitor will light off and heat will blow for about 10 seconds, then motor sounds like it reall takes a load and pops the fuse... 15 amp. Overall time that it stays running is approx 45 seconds to a minute and then it pops. What would cause the motor to seemingly take a higher load all of a sudden? I'm only assuming it's a motor problem as right before the fuse blows, the high pitch whine of the motor starts getting deeper and begins to slow down a bit. This is in a 2004 Keystone Sprinter 5ver, 24k BTU. Any HVAC guys out there that can help this plumber out?? Thanks in advance.



Note: I won't be able to get back on TDR until Sunday afternoon.



Bert

 

[JMetzger]

Sounds like you have a fan motor about to dump. If you can find an dc amp meter you can read the amps on the fan motor only. You can also use a Fluke multi meter to read the amps. If you can't find a meter, when it blows the fuse reach in and see if the fan motor is hard to turn or if the fan motor is hot. It could be a bad circuit board but I will bet on the fan motor. You can remove the board and have it checked at an RV dealer. I also doubt that it is the gas valve. Hope this helps. Jack

 

[JMetzger]

I also forgot to mention to check all wiring connections for loose or corroded. Don't forget the ground as it does't take much on a 12 volt system to send up the amps.



Jack

 

[KBertetto]

Jack,

Thanks for all the ideas, turned out to be a badly corroded ground wire. I replaced it and all is well, thanks again.



Bert

 

[jjordan1]

I would check for wasp mud nest. Had the same thing happen to one of our older units. I now put the screen over the exhaust tube. Good Luck