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Topic: No Heat !!!  (Read 1030 times) previous topic - next topic

No Heat !!!

Hello guys here we go  >:(  my 8535-2 furnace in the living forward compartment ' That's bluebird lingo  :-X  Any way here's whats driving me crazy  :P  when i turn it on . now this is after doing this for a long time! after i turn it on i run out  & around to the heater. The blower comes on & after so many seconds i smell gas & hear a ticking for a brief moment blower never stops then same thing gas & tick sound fan never stops then gas tick tick tick  fan never stops then just fan . so i pulled the burner assembly . burner has been burned  up meaning a big hole has developed in the burner deal .  not sure what to call it ? so i go on eBay and buy a two piece set ignitor & burner install and it does the same thing  :-X  now here's the deal the furnace in the bed room works fine! it well run you out of there  :-[  now when i first tried the forward furnace it didn't tick tick tick and no gas smell just fan so i swapped the automatic ignition system boxes .and got the gas & tick tick tick .so there it is tick & gas and it well not catch . NO HEAT :'(       

Re: Here we go!!!

Reply #1 –
@lovetogo You've done all the right things. The Atwood furnaces are pretty simple. The controller on the left, fan in the middle and the burner on the right. All accessible from the outside.

The startup process is

    • Thermostat calls for heat
    • The fan kicks on
    • The sail switch says I have good air flow try to light the gas
    • The controller opens the gas valve and sends a high voltage pulse to the ignitor
    • The burner ignites and you have flame/heat
    • Heat continues until the stop limit switch kicks in
    • When stop limit swith kicks out goes back to 3 above until thermostat set temperature is reached
    [/list]

    Sounds like you make it through first 5 steps but no flame. I was all set to call this a sail switch problem but don't think so since you hear the igniter go off. Next I was ready to call it a gas flow problem but you smell gas so no go there.

    You could try switching the burner assembly from the back furnace with the front. Since you already replaced the burner you are schooled in doing that drill. :) If that doesn't work I hate to say it but you may have to call in "Bob" the propane appliance guy. :(

    You might want to check if you have oil in your LP line. See my post about that here. LP Maintenance

    Good luck. Everyday is a new adventure!

    see ya
    ken

    Re: No Heat !!!

    Reply #2 –
    All I can think of is that it's not sparking where the gas is.  Could be caused by a shorting high voltage wire.  Might try to swap out the high voltage wire with the one in rear furnace.  Just throwing out ideas.  No experience with this kind of problem.

    Re: No Heat !!!

    Reply #3 –
     Thanks guys for all your help, swapping out the burners first .  :-X

    Re: No Heat !!!

    Reply #4 –
    The flame sensor isn't sensing ignition. The controller thinks the burner didn't ignite so it's cycling through three times before shutting down the burner. The fan keeps blowing cold air forever after the burner shuts down. The metal rod inside the burner is the flame sensor. It works by sensing the change in resistance when the flame is in contact with the rod. On some burners the same rod that ignites the flame is also used as a flame sensor. On yours it's probably a separate rod (?) Clean the rod with steel wool and the contacts of the wire on the end of the rod and try it again. The same thing happens to my water heater sometimes... After you get this fixed we can work on your writing skills  :))  ...just kidding, just kidding!

    Re: No Heat !!!

    Reply #5 –
    I had a similar problem. Turns out my 1989 thermostat was the culprit. Why, I don't know, but I put a new one in and everything worked as it should. I thought any thermostat would work as there was nothing on the old one that stated 12V. WRONG!! Get one from a RV dealer.

    You might try swapping the bedroom thermostat with the one up front. Also, check to see if you have the propane sensor operating or tripped. If it is over 5 years old it is time to replace it. Newer ones have automatic time-out built into them so the thermostats are only good for five years. You can test your sensor by holding an UNLIT propane match up to the sensor while holding the trigger in the open position.

    Re: No Heat !!!

    Reply #7 –
    Nitehawk, you're saying the new LP gas detectors have a built in expiration after five years? This includes the $200+ gas detector that can turn off the solenoid valve at the tank?

    Re: No Heat !!!

    Reply #8 –
    Well, lovetogo, I was smiling when I commented on your original post, but clearly didn't write it appropriately and it came across too snarky in print. 

    Regardless, I'm glad you got some good advice from the good folks here (people much more knowledgeable and fluent than me) and wish you the best!  :-)

    Re: No Heat !!!

    Reply #9 –
    Yes, Scot, but the new sensor does not include the shutoff. The newer coaches (as posted here on our website) do not have the shutoff solenoid. I removed the solenoid from the tank and replaced it with a 3" long pipe nipple.
    When we bought our sensor at our RV dealer it said right on the package that it would time out after five years and, If I recall, it also said the sensor would notify us in some way.

    Re: No Heat !!!

    Reply #10 –
    up date, took the good automatic ignition system board back to bedroom furnace and it fired rite up even though it sounds like theirs a bearing going bad . But it works :) but i noticed that the ignition wire is black not red like the one on the bad furnace . But i hear the igniter ticking  ;) but i think I'll swap them out like was suggested in one of the many responses i have received  ^.^d  then if that not it I'll change out the thermostat . BUT FIRST I THINK BECAUSE I HAVE TAKING OUT THE BURN UNIT DOWN TO A SCIENCE, I'LL SWAP IT OUT FIRST THAT WAY I CAN ALSO SEE HOW CLOSE THE IGNITER IS TO THE BURNER  :o   

    Re: No Heat !!!

    Reply #11 –
    @lovetogo While you're in there clean up all electrical contacts and tighten any that feel lose. Since you have everything apart you might as well pull the cover on the motor and put a drop or 2 of oil on the fan motor shaft to try and get rid of the squeak. Doesn't always work but worth a try.

    see ya
    ken

    Re: No Heat !!!

    Reply #12 –
    I pulled the fan motor in our furnace last year because of a squeak, drilled a small hole in each end bell, oiled it with turbine oil, no more squeak. You can get the oil at Ace Hardware,( Norvey zoom spout oiler ) I also did this to both of the AC motors when I cleaned the units.

    Re: No Heat !!!

    Reply #13 –
    We are still using our original propane detector, but have removed the solenoid and also have mounted a new propane detector on the opposite wall.  Our propane hot water tank sometimes causes a false alarm on one or the other detector.
    We figured that since the original one is still working, why remove it when we installed a new detector.  Nice to have redundancy for this important detector.  But we did add switches to the 12 volt power wire so all detectors do a complete reboot after an alarm.
    We also have redundant ionization & photoelectric smoke detectors and redundant CO detectors.  Can't have too much of a good thing.

    Re: No Heat !!!

    Reply #14 –
    Are you sure the gas valve is fully opening?
    JD

    Re: No Heat !!!

    Reply #15 –
    Up date!!! put burner assembly from working furnace in none working unit and it fired rite up  ;)  also  used red igniter wire from none working unit so thats not it . that means the thermostat is OK as-well  ,  The other thing that could be going on is the after market parts i used, burner electrode kit . But I'm getting gas & the ticking sound  :-X

    Re: No Heat !!!

    Reply #16 –
    By parts swapping you are narrowing it down!
    Hope you get it working by happy hour!

    Re: No Heat !!!

    Reply #17 –
    @lovetogo Since you have it out I'd try the new burner in the other furnace. You never know it might work.

    I had one that would work in one but not the other. The really bad news is that Atwood doesn't make that burner anymore and believe me I did a lot of looking online for it. Tried the newer model burner which looks close but has slightly larger holes. It worked in the front but not the back. It does make a weird farting sound when it lights on rare occasions. I just turn it off and back on and it stops.

    Ended up replacing the rear furnace. It made rattling noises that I couldn't fix since day one. Was glad to see it go. Replaced with a 2 stage Atwood that I love. Much quieter.

    see ya
    ken

    Re: No Heat !!!

    Reply #18 –
    Did you clean the flame sensor rod?

    Re: No Heat !!!

    Reply #19 –
    Scott i replaced the igniter and burner with after market ones. Kenhat  i would love to just replace it with the new two stage one but i need 8 new air bags & full body pant job & Harley , not new though  :) & 46" Smart TV % & fishing kayak & new hot lady friend & why I'm @ it a  nice three horse slant sundown trailer that i could build a carrier on top for the kayak . SO ANY IDEAS  >:D  Oh and by the way I'm smelling LP gas all the time @ the furnace that's working  :-X