Furnance not blowing hot air

[clema]

I have a suburban NT24S furnance and when I turn the t-stat on, the blower motor works but I can't hear the thing cycling or trying to ignite, I called the local dealer and he thinks it is the circuit board, he also want about $150 in labor to replace it plus the price of the part. Has anybody ever ran into this problem. How hard is it to replace the board, I am mechanically inclined, but I have never had a furnace apart. Any help on this would be great.
Thanks in advance.

[waynek]

First thing to do is to turn off the furnace reset the thermostat. go outside before the fan starts, YOU can HEAR every thing much better outside listening to the exhaust. 15 to 20 seconds after the fan starts the gas valve and sparker should start together, if it does not ignite you should smell propane. the only thing other than the board to cause it not to ignite SHOULD BE no propane to ignite you have not said what your rig is that does make a difference in the propane system. I can give more if you give more info waynek

[clema]

Waynek, Sorry about that it is a class c georgie boy motorhome the year is a 1983. I have propane to my stove and waterheater I am assuming I have propane to my furnace. I will have to check tonight for the smell of propane. I have the cover off of the heater so I believe I would be able to hear if the furnance is trying to ignite but I will try your method of listening by the exhaust tonight.

[stevesandidge]

on one that old it could also be the igniter is corroded, which will impair spark.
remeber that this is a gas appliance, if you take it apart n put it back together wrong, it may kill you!!! carbon monoxide, and gas connections must be checked for after each time they are worked on. a gas detector will cost ya about 150 dollars, and a carbon monoxide tester will run over a hundred. the card is about 125 bucks msrp. if you can, find a mobile rv tech, they usually charge less than dealers. we charge 65 an hr and we are 5bucks under the lowest dealer rate, and 30 bucks under the higher dealer rate.
steve sandidge
rvia certified rv tech
kingsport tn

[whodo]

clema
Here is a excellent web site with step by step instructions & pictures that should help you trouble shoot your furnace problem.
http://www.rverscorner.com/furnace1.html

Now as others have already stated you need to be careful when working on these appliances. If you don't feel comfortable about performing any of these trouble shooting or repair steps then be sure and have a qualified repair person perform it for you. Money can be replaced, lives can not.

[clema]

Thanks for all the info it was very helpful. I will keep in mind the comments about carbon monoxide and gas that is very true thanks again.

[stevesandidge]

one more thing on checking for leaks: DO NOT USE SOAPY WATER!!! soapy water will cause the brass to get brittle, discolor and may crack the nut! if you use a liquid leak detector, available at most camping world stores or even some lp gas suppliers.
steve sandidge
rv tech

[clema]

Good tip steve thanks