furnace

[chris&sharon]

my furnace dose not blow hot air? have a 1976 821 f rear kitchen,rear bath.fan works but no hot air.i replaced the fuse still no hot air.what to do were to begin? any help will be great.thanks chris

[handyman]

I know this is a dumb quistion but is your propane on and do you have propane also check and see it your pilot is lite if the unit hasent ran in a long time it may just need time to get the gas to the unit

[chris&sharon]

hi jim,not a dumb question i thought about that,so i turned on the stove and it worked? also i turned the furnace on 10-4-03,the fan worked but no heat.we hade this problem another time and replaced the fuse that worked.but not this time! also about the pilot light? how do you check this? the furnace sets under the fridge.i pulled the cold return and all i saw was two holes. one was cold air returne. other was wires and gas line.under fridge could not much.because acess was tight. now what.

[mollerus]

Chris:  Open the cabinet door to the right of your refer.  Between the bottom of the cabinet and the floor is a wooden door that hinges open to expose your heater unit. To the left of the metal box that holds the furnace unit is a brass propane valve that is the master shut off to the heater. The gas is off if the handle is at 90 degrees to the copper propane pipe and open when it is parallel to the pipe.  Make sure it is open.  Turn your thermostat to the far left to the off position. Your fan should not run if the thermostat is off. It is dangerous to try to light the pilot if the thermostat is on, possibly leading to a serious explosion. Remove the cover from the front of the heater box.  The pilot light opening is covered over by a removable cover with two thumb screws.  Loosen the thumbscrews and swing the cover out of the way.  The pilot light and thermocouple is about ½ to ¾ of an inch past the opening. Stick a lighted propane barbeque lighter into the pilot light hole and then press and hold the knob in at the far left and hold it in for 15 seconds after the pilot light ignites.  Remove the lighter and replace the cover over the pilot light, then check to be sure it is still burning.  Replace the front cover on the heater box. Then, and only then can you move the wall thermostat up to your desired temperature.  The furnace should then ignite and the fan come on and you'll have heat in a few minutes.  If the pilot will not light you may need to replace the thermocouple which you could probably do yourself or head to you nearest RV shop. That master shut off valve may be off and should be turned off if you are not using the furnace for any length of time. Good luck.

[Conrad]

I had to replace my igniter board.  I took the board to an RV shop that had a board tester.  The tech puts your board in to the tester and can tell you if it is good or bad.  

I had to remove the furnace from its enclosure below the fridge.  A small jack might be helpful if the fridge support has sagged over the years.  Tight fit!

If you do the work yourself, make sure the propane is off, the electrical is off and observe any and all safety precautions.  There are two wires that go to the wall thermostat and there should be two for the fan power (12Volt).

I have some pictures if interested.

[chris&sharon]

bob#15 i did what you said,but there was no ingator button?  conrad#20 i would very much like pitctures.thanks.

[HPotter]

First of all, which furnace do you have? The Suburban furnace, unlike the Coleman, has no pilot light. Each time the thermostat comes on, the gas is turned on, and a few seconds later the igniter board generates a spark in the combustion chamber to light it. If there is no ignition, the gas is turned off. A common problem with this on is rust or scale shorting out the spark gap. If you have this type of furnace, open the door mentioned above, the undo the snaps holding the metal cover on the furnace and swing away the mica window opening into the chamber. Take a short stick, like a matchstick and stir around the area inside  and see if you can dislodge the scale. Close the mica window and again turn up the thermostat. You should be able to see and hear the spark igniting the gas.
I've had to do this to ours many times over the years, and it always seems to work. Good luck!

Harold, ACOC 886

[Conrad]

Chris and Sharon, I will send pix when I return home this weekend.  

Do you get any flame at all?

I had flame for a short period, 5 sec or so, before it would extinguish.  I followed the same path that Hpotter described.   It turned out to be the igniter board which is only accesible by removing the furnace.

[chris&sharon]

HI, Chris here first off thanks to everyone for the help. i found out i have a suburban furnace. i removed it on sunday i will have a r.v. shop do a bench test on it. IM sure they will tell me i have a bad inghitor or bad bord? anway i will let you all know the out come.again thanks alot for the help and suport.

[Conrad]

my email is cinqmars@harbornet.com  

please contact me there and I will send some pix.  I don't know how to send them via this websites program.

[chris&sharon]

what a learning curve, to make a long story short All I had to do was clean out my burner. I tryed to have Ti bench tested but the R.V. shop first told me It was the cirtit board after that faild they told me to clean the buener. and that worker.Again thank you all for the help.C.D. Green

[HPotter]

One more point: Conrad mentioned above that the shelf the refrigerator rests on may have sagged over the years, making removal of the furnace face cover difficult. This happened to ours, and we fixed it by welding a couple of 1-1/2 inch square metal plates on the ends of the eyelets on a turnbuckle about 7 inches long. We then placed this vertically between the shelf and the floor, just to the left of the furnace. By turning it we had a screw jack that pushed up on the shelf and lifted it back into its original position. It's still there about 3 years later. Works fine.

Harold, #886

[bridgie7@juno.com]

It seems all the advice is great and will help to fire the heater.  For that reason I carry an old tooth brush with me and clean the orifice of the heater and lthe burning unit in the heater , as well as the refrigerator, where the flame shows.  Spiders love to llive in the openings and cover the openings with web, plus you get dust on these units. Only takes a minut and usually works fine after.

[cat]

I realize you folks discussing furnaces live in the Northwest and depend on using your furnace but if you live in an area not quite as cold,  and shore power is available, an electric heater works really well to take the chill off in the morning.  I run mine off the GFCI outlet located just inside the entry door on the rear kitchen model.  Works great!