Utah's Fiery Furnace of Hell Needs a Circuit Breaker
December 2, 2006 7:46 AM

My wife changed the filter on our gas furnace yesterday, and now it doesn't work. I pulled off the front cover and on the upper right is a small black pressure switch of sorts. I originally thought it was supposed to be held shut by the cover, but that is not the case, as they don't match up.

From reading the manual, I believe this is the circuit breaker for the furnace/blower. When I push the protruding switch back in by hand, the furnace fires up. It is spring loaded and won't stay in place, however.

1. It seems accessible--can I swap this out myself?
2. What did my wife do to break it?
3. Would the local hardware store carry something like this?

It is a Lennox Pulse furnace and I have the paperwork for it, and our recently purchased home is circa 1968. We have been using the groovy wood stove since yesterday, and it is about 25 degrees here in frigid Utah.
posted by mecran01 to Home & Garden (19 answers total)
Furnace guy on the phone seems to think it may not be a circuit breaker. Maybe the lid *is* supposed to hold that switch in.
posted by mecran01 at 8:05 AM on December 2, 2006


Maybe you are trying to put the cover on upside-down?
posted by lee at 8:07 AM on December 2, 2006


My furnace (also a Lennox) has the same switch, held on by the filter cover. The cover was probably re-installed wrong somehow.
posted by deadmessenger at 8:09 AM on December 2, 2006


Ah, you people are rockstars of the internet. I'm off to check it now...
posted by mecran01 at 8:14 AM on December 2, 2006


Ok, upon close inspection the cover cannot push down this switch. The way it lines up, they don't touch each other. Unless a piece fell off. So I'm still not sure if this is a switch or a blown circuit breaker that won't reset.

I'm afraid to tape it closed.
posted by mecran01 at 8:24 AM on December 2, 2006


Lennox manuals, maybe some help?
posted by lee at 8:35 AM on December 2, 2006


can you verify that the new filter is identical to the old one?
posted by lester's sock puppet at 9:25 AM on December 2, 2006


The new filter is an inch too wide and crammed in place. It does not come into contact with the aforementioned switch, however.
posted by mecran01 at 9:36 AM on December 2, 2006


Would a properly sized filter allow the cover to reach the switch?
posted by Popular Ethics at 9:38 AM on December 2, 2006


The cover on my old-ass heater doesn't line up with the switch unless you really jam it in *hard*. As in, when I put the cover back in at first it will stay in place but is not over the switch. I've got to punch it downwards--it is then very firmly is place and presses down the switch. If it's easy to remove the cover, then it's not in the correct position (at least with my heater). It takes some wrestling to get that cover on and off.

The setup is a safety mechanism to keep the furnace from turning on without that cover in place--if someone's tinkering around in there the cover would be off, and it'd be impossible for the thing to start up without the switch pressed on. I wouldn't be scared to temporarily tape the switch down as long as the cover was sort of in place. But that's just me and the risk I'm comfortable with. I would probably light a fire in my kitchen trashcan if it were 20-odd degrees and I had no heater.
posted by neda at 10:34 AM on December 2, 2006


My wife just went out for some more firewood. I am starting to eye the two ukuleles on my mantle as possible fuel sources. We have a large kerosene space heater that I've fired up, and it only took me 45 minutes to get the safety guards in place (thanks Toyoset!).

But seriously, I have a much better idea of how people under siege and in other situations were able and willing to burn books and furniture.

I will continue to look at the cover/safety switch and try to figure out what is going on. I bet the cover does slide downwards, but that seems like it would leave a gap. Enough words! back to work...
posted by mecran01 at 11:05 AM on December 2, 2006


my next step (after burning a few copies of any daniele steele and tom clancey novels) would be to go out and buy the right size of filter that you had before. i bet that is your problem. if you want to test it, try reinstalling the old filter first, and see if that works.
posted by lester's sock puppet at 11:24 AM on December 2, 2006


I agree with lester's sock puppet. I suspect that jammed filter is not allowing the swich to make contact. If the furnace does run properly when you hold the switch down then why, as an alternative, put something between the cover and the switch to hold the switch in place. But I would do as lester said and put the old filter back in or no filter at all and put the cover on. It almost has to be some physical connection causing the problem.
posted by JayRwv at 11:42 AM on December 2, 2006


I am not being clearn but the filter is not anywhere near the furnace door. More to come...

ask.metafilter should have a betting feature...
posted by mecran01 at 11:59 AM on December 2, 2006


The switch is absolutely supposed to contact and push in the switch. If not, then you are not replacing the cover correctly. Most furnaces have the switches to prevent the furnace from running with the panel off.

Many furnaces have two cover panels and you may have accidentally switched them. Have you tried swapping the upper and lower? Usually the lower panel that covers the filter and fan is solid and the upper that covers the burners has louvers.

Also there are usually tabs and slots on the upper edge that engage to hold the cover in place. Sometimes it can take a lot of banging and prying to make them slide into place. Make sure the panel is not upside down.

If you can't get it figured out there's nothing wrong with taping the switch closed while you wait to get someone to fix things for you. The panels are mainly to keep little kiddies and pets from poking at things while its running, although you may end up drawing air directly into the furnace and not through the air filter. At least you won't freeze while waiting for the repairman.
posted by JackFlash at 12:12 PM on December 2, 2006


Hey, I think I fixed it.

The furnace consists of two access panels, the upper and lower.

The lower panel accesses the filter.

The upper panel slides vertically about an inch. In order to fully close the lower panel, I had to slide the upper panel upwards, then fully push in the lower panel, which brought it into contact with the safety switch. It was like a chinese puzzle box.

The confusing thing was, as always, sheer ignorance on my part! That, and the fact that the lower panel looked like it was in place when in fact IT WAS NOT.

Wow, I just saved $80. Thanks metafilter, I am naming my next pet after you. My wife is going to be happy! My children are going to be warm, and we know now how to use our wood stove and kerosene heater and are stocked up on wood (ok, two bundles) and kerosene. I feel like Pa Ingalls.
posted by mecran01 at 12:31 PM on December 2, 2006


burn the ukuleles anyway...
posted by horsemuth at 1:00 PM on December 2, 2006


Better to burn the ukuleles than use that kerosene heater inside your house.
Welcome to heaven, here is your violin.
Welcome to hell here is your ukulele.
posted by blink_left at 1:10 PM on December 2, 2006


"burn the ukuleles anyway..."

Savages! These are *real* ukuleles, and sound quite nice.
posted by mecran01 at 11:56 AM on December 3, 2006


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