Lennox Pulse furnace air valve

mekanic

What is the required clearance for the air flapper valve on a Lennox Pulse G14Q3-60 furnace? Thanks

newtech

When was the last time you had the heat exchanger pressure tested? You might want to have a Lennox certified co. to check it. If set up wrong it will missfire and cause all sorts of problems. I'm sure that Yuri will be along soon for more advise.

Me personally I won't touch them. Have been doing this for 20yrs, but those furnaces are not to mess around with, unless you have the propper training.

yuri

There is no required clearance for an air flapper valve. (Be more specific why you are asking). The membrane is supported and the 2 plates are separated by a specific sized spacer washer for each model/series and year it was built. That gives it the room to "flap". It should be pressure tested every 4 yrs for safety. Only a trained Lennox tech can do that.

__________________
"Cut it twice and it is still too short".
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

hvaclover

I repair pulses. But by the time an independent like me get's the repair call, they are in such bad shape a $200 repair has turned into close to a grand.
All because they have been neglected so bad.

__________________
Just slow, not stupid.

yuri

30th anniversary of the tough old buzzards. Not going to miss them when they are gone.

__________________
"Cut it twice and it is still too short".
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

hvaclover

look familiar?

__________________
Just slow, not stupid.

yuri

Probably a LOT of them failed from lack of maintenance ie: anybody ever clean the secondary coil fins? overfiring? check the temprise? clean the evap coil? not a furnace you want to overheat as it may get red hot on that chamber in places.

__________________
"Cut it twice and it is still too short".
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

mekanic

The heat exchanger was replaced a few years ago under the Lennox replacement program. It has not been pressure tested since and I am thinking of having it done before this winter season starts. In the meantime, the Lennox manual indicates that the air flapper valve has a specified clearance between the two plates, but I can't find that specification anywhere. Thanks for your help.

yuri

Post the complete model and serial # and I can get into the tech site. I have never needed that spec as the spacer washer takes care of it. Is the furnace having problems starting. The flapper membrane gets dirty/stiff/small holes in it and needs replacing every couple years and causes startup problems.

__________________
"Cut it twice and it is still too short".
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

mekanic

The furnace model is G14Q3-60-C6 and the serial number is 6387B21550, thanks for your help

yuri

The specs for that flapper vary from series to series and only a Lennox parts guy knows. I have serviced them for 32 yrs and never needed them. Nothing you can adjust on it anyway. I looked at the troubleshooting guide and service bulletins etc. There are specs and they love fine details but in the real world that spec is unecessary. Either it flaps or it doesn't.

__________________
"Cut it twice and it is still too short".
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

mekanic

So once I clean the plate surfaces and replace the flapper valve, you just tighten the centre screw so that the movable plate is just touching the spacer washer and that provides the correct clearance for the flapper valve to move properly? (So the spacer washer provides the correct clearance for the flapper valve).........The so called furnace "tech's" that replaced the valve a couple of years ago left the center screw too loose, (so I think the flapper valve was not opening and closing properly), and didn't tighten all the outside circumference screws evenly, in fact a couple of screws could be removed with my fingers!
Thanks

yuri

The center screw has a self locking teflon nut to prevent it unscrewing from vibration. Snug it but don't overtighten it. Nothing moves other than the flapper between the plates. Make sure you get the smooth side with writing out to you on the outer plate. VERY simple once you do it once.

__________________
"Cut it twice and it is still too short".
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.