Any furnace guy's out there... no heat!

[nycredneck]

Hey guys it's that time of year. I have a Lenox G26Q3-75-6 furnace.

So I turned off the AC and tried starting the furnace and she no want to work and being an electrician I took it upon myself to figure out why. First off I noticed the flue transition hose from the combustion air blower to flue pipe was a torn ( it'a foam type, piece of crap) and looked up buying a new one online... the replacement part is now a bent piece of PVC and cost $201.00, soooo I cut off the torn piece and made a connector with a 2" pvc and rubber hose coupling, it worked like a charm. But still no heat.

  It seems when the thermostat calls for heat the combustion blower fan starts to turn for a few seconds then stops. I did get it to run for longer but the gas valve never opens so I'm thinking maybe pressure switch, or primary/secondary limit switch. I did try to check the pressure switch by disconnecting the vacuum line and made my own vacuum and metered the switch and it worked but never tested it with the blower fan going. The blower fan for the most part turns off after a 2 or 3 seconds. I don't understand the flashing beacon lights completely either. Simultaneous slow flashing means it's working properly... well it's not.

  Anybody out there with experience on these furnace, I know it's not that complicated, I just wish I knew which part to change. I have fixed mine before when the combustion blower stopped working last season when it was in the teens.. my wife thought I was a hero then, not so much now as I may have to bite the bullet and call in the pro. 

Thanks guy's.

[Haskell_Hunter]

I'm not a furnace guy but there's a Holiday Inn Express at the end of my road.  I work with computers, so I know where everything online is.  I attached the manual for your furnace.  It might give you some guidance in the short term.  There's a troubleshooting section at the back.

 

I also attached some serve thing.  Might have some additional information too.

L0406249.pdf

G26 SERVICE.pdf

[nycredneck]

I appreciate that Haskell, thank you. I did the same thing myself a half hour ago.. after spending two hours fooling with it, although I did fix that flue transition hose  . Money is tight and ya got to save it where you can.

 Oh and I'm not a furnace guy either... but I do play one on TV.

Edited October 12, 2013 by nycredneck

[Axiom]

Interesting...  Sounds like your saying both air blowers run for about 2 or 3 seconds then kick off... According to the schematics they only have 1 thing in common other than the 24v supply volts.. S51 or the door switch...

[nycredneck]

Not both, just the combustion blower for a couple seconds. 

[Axiom]

well, with the symptoms you discribed i get as far as the roll out switch...

[nycredneck]

So now with a demand for heat from thermostat the combustion blower goes on, I get continuity through pressure swith and the limit switch is closed ( which it is normally ) but it seems igniters are not comming on thus gas valve not opening. I think I've eliminated a few things but still don't know what IS wrong.

[sam3]

Change your air filter. At the top right of the unit, there is a reset switch. You may have to feel around for it. Reset and try it again.

It's possible you weren't getting enough air passing through the unit and it tripped. Happened to me twice. I change the filters every month now.

[nycredneck]

I GOT IT !!!   Thanks to Haskel ,Sam and you too Axiom for your time  . 

What I did was interpret the diagnostic codes telling me it was the pressure switch although I knew it was good. So next what I did was remove vacuum line exiting the vacuum switch and made positive then negative pressure which unstuck something either in gas valve or igniter. Yes, I put the line in my mouth and gently blew and sucked ,( whats a girl to do ) heard a few clicks after couple a times and put it back on... it did the trick. Funny because both upstairs and downstairs furnace were not comming on and I was able to get both running with same fix.

  So lesson learned is I will turn heat on once month for a few minutes all during warm months after heat is off as to keep vacuum switches & valves moving and not sticking when off for a long period of time.

Edited October 12, 2013 by nycredneck

[Axiom]

Thats great..  .... was going to say if the problem aint your roll out switch the next thing to check woud be the vacuum switch but,  i dont like to put the cart before the horse ...so to speak..

[Haskell_Hunter]

So if I understand correctly, you blew it to turn it on, and you're both happy now?

 

[nycredneck]

Funny how that works, sometimes you just have to get on your knees and blow for a happy ending!  

[sam3]

That's great. Glad you got it working.