What does it mean when air blows out the pilot hole?


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Old 02-05-10, 03:28 PM
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What does it mean when air blows out the pilot hole?

(help!)
My pilot light keeps blowing out on my gas furnace.

If you light up a lighter and hold it in front of the hole where you light the pilot light, a huge gust of wind will blow out the lighter!

To test the theory that it's air blowing from the exhaust in, I went outside and completely blocked up the vent with duct tape. It still blows air from the inside by the pilot light hole, so there must be a crack or leak somewhere, right?

Any suggestions on what to do to fix this??
 
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Old 02-05-10, 03:54 PM
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Sounds like you have a cracked heat exchanger. Heat exchangers cannot be repaired unfortunately, and you need a new furnace installed. Head aches and in rare cases death can occur from cracked heat exchanger so I suggest calling a technician.
 
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Old 02-05-10, 03:54 PM
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is the blower running?.....if it is blowing your lighter out with the blower running you need to immediately have the heat exchanger checked by someone who knows what they are doing...this is a potentially very hazardous situation
 
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Old 02-05-10, 05:38 PM
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Air out of pilot hole

I disagee with ecman. If the pilot were out & presumably the blower off, a cracked heat exchanger would not exibit the symptom you are experiencing. I suspect you have a strong negative pressure in the house. As a test open a window just a crack & hold a piece of tissue near the opening. The direction the tissue moves will tell you if air is rushing in or out.
This is getting to be a common problem in tight houses especially if a water heater, dryer, kitchen or bath exhaust fan is on & most commonly, there gas logs in a fireplace.
 
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Old 02-05-10, 07:24 PM
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That wasn't me. ...........................
 
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Old 02-06-10, 08:57 AM
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Red face Sorrry EC

I appologize. I saw the poster's name begin with an "e" & with you being the only regular with a name begining with "e" dummy didn't pay attention. I should read more carefully.
 
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Old 02-06-10, 11:38 AM
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Accepted. That is what I thought likely happened.

It sure be nice to find out from pie, what he is finding out.
 
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Old 02-06-10, 05:30 PM
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Sounds like a mobile home furnace to me. Cuz thats what happens.
Or a sealed combustion wall style.
Or ?
 
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Old 02-08-10, 10:25 AM
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The air is blowing IN.

It blows in. Then stops. Then blows in again. (depending on what? IDK... just some outside air)

If it is blowing air in from an unknown source what does that mean?

ps: i do know mice and squirrels are in the walls trying to get heat when it got below 0.
 
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Old 02-08-10, 03:17 PM
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Please tell us what furnace you have?? Name and model number
 
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Old 02-08-10, 04:12 PM
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Originally Posted by Piejack
The air is blowing IN.


If it is blowing air in from an unknown source what does that mean?
Some effect is pulling air out of your house, either from wind currents causing a negative pressure on the downwind side of houre, drawing in air on the upwind side of the house. (If you have a leaky house this can happen).

Or you have a top window sash that slipped down and is hiding that way behind blinds or drapes, and you do not know it.

Or you have, or have had on, some device that exhausts air from the house. Bathfan, dryer, rangehood.

Or you have one or more other flue pipes, that when air goes up one flue pipe(say gas water heater, or a fire place), the air tries to come down another (your furnace). Why would it do such a thing?: To equalize the air pressure.

Or you are beleagured by air pressure inversions, where less dense inside air is where your furnace is, and more dense air is outside.
 
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Old 02-09-10, 09:13 AM
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It's about a 20 yr old 4'high by 2'wide and just says "Morningglory" on the furnace.

It heats my workshop area (1 room).
 
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Old 02-10-10, 07:05 AM
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Any ideas what to do to stop the airflow so the pilot doesn't blow out?
 
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Old 02-10-10, 01:29 PM
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Air thru pilot hole

I don't understand how it can happen with the exhaust blocked unless the vent has come apart in the attic?
Does the furnace have a draft hood? There has to be something creating draft thru the furnace.
 
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Old 02-10-10, 04:35 PM
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Does your workshop leak like a seive and/or have other exhaust vents/chimneys in it? Tell us as much as you can about that shop and even what you use it for. Like is it for woodworking and you are exhausting sawdust outside? Give the dimensions. Tell us which side faces west. Tell us if door(s) and windows(if any) leak badly. Is the ceiling finished or is it open to the peak with say a metal roof on it? Tell us if it is usually windy there. And is the shop a single level building that has nothing above it like no apartment above it?

An interesting little mystery that one would think not too hard to solve, with all the facts.
 
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Old 02-11-10, 07:30 AM
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Does your workshop leak like a seive and/or have other exhaust vents/chimneys in it? No. There was a dust exhaust hole, but I stuffed it with tarps so birds and cold air wouldnt get in. The hole went out of the shop to my garage where a storage bin held the sawdust. The bin has been removed and was an open hole, now hopefully still sealed. I'll check the quality of the seal because it just had tarps.

Tell us as much as you can about that shop and even what you use it for. Like is it for woodworking and you are exhausting sawdust outside? It's where I build things, fix things, I store all my tools and paint in there, in the cabinets. I also built a pool table in there to play on, have video games, a basketball hoop set, an air hockey table, foosball, and video games for the kids.

Give the dimensions. about 20 foot across by 20 foot, then there's a dogleg to a section about 15 by 25 foot across.

Tell us which side faces west. The furnace is on the South Wall, and the air outlet faces south, so it's getting air from West, South and East.

Tell us if door(s) and windows(if any) leak badly. No, there shouldn't be any leaks. The main door is a double-door, french door style and is double sealed fairly well and closed shut.

Is the ceiling finished or is it open to the peak with say a metal roof on it? The ceiling and all walls in the shop are finished with drywall, and the floor is wood and painted.

Tell us if it is usually windy there. It can get windy (you mean outside?) as in Minnesota. The shop is in a wooded area on 2 sides, and a lake and on top of a hill to the west, so any wind from the lake can get to the barn pretty easily.

Is the shop a single level building that has nothing above it like no apartment above it? Above the shop on the second floor is open. I can get a ladder up there and store the kids kiddy pools. I've set traps and killed a few mice, but I havent caught the squirrel yet. I laid out a sticky trap and the squirrel struggled and got free, but his fur remains. I've seen the squirrel, so I know he gets in and out of my barn somehow. I've also heard him digging in the walls, the little bugger. The walls on the barn are metal (it's a pole barn), and the roof is a kind of a wavy white shingle strips.

Out of curiosity, I cut a square of the drywall and removed a piece of drywall about 5 inches to the left of the furnace to get a peek. I wanted to see if there was any rust. I did find a mouse house where I could see mice living next to the furnace to get heat, but there was no rust. The walls are filled with loads of insulation. I replaced the drywall square and sealed the hole.
 
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Old 02-11-10, 04:15 PM
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Originally Posted by Piejack
(Ecman quote) Is the shop a single level building that has nothing above it like no apartment above it?


(Reply by Piejack) Above the shop on the second floor is open. I can get a ladder up there and store the kids kiddy pools. I've set traps and killed a few mice, but I havent caught the squirrel yet. I laid out a sticky trap and the squirrel struggled and got free, but his fur remains. I've seen the squirrel, so I know he gets in and out of my barn somehow. I've also heard him digging in the walls, the little bugger. The walls on the barn are metal (it's a pole barn), and the roof is a kind of a wavy white shingle strips.
Ahhhh. An opening leading to a higher level? Disappearing squirrels (indicating a sizeable hole? We may be onto something here. This could create a chimney effect, similar to a windtunnel effect. What is that storage area like up there? Can you see the underside of the roof up there?

What happens if you say you were to light a lighter, match or incense stick, in varius areas in the shop, and then say go like you are going to climb the ladder, and then hold the lit item off to the side some? Will an air current draw it toward the ladder opening?
 
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Old 02-12-10, 07:28 AM
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Imagine a 2 story barn. You walk in the door and it's open to the ceiling. I store 2 boats inside the pole barn, and a truck and other items.

At one end of the barn there are double-doors going into the shop. If you stand outside the double-doors, and put up a ladder you can climb up and walk on top of the "shop" area. It's a wooden enclosure inside my barn, and sheet-rocked inside.
 
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Old 02-12-10, 05:22 PM
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Like I said, see what happens outside the furnace, if you light a flame or smoke to see how that behaves. See if that behaves like the pilot.
 
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Old 02-15-10, 07:34 AM
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YES! I got it to light.

It's been quiet and non-windy this weekend, so I was able to light the pilot light, and turn on the heat.

It ran now for a couple days and when I checked yesterday it was still on. It got so hot it melted the plastic on the exhaust tube outside (bought a new metal tube that had plastic pieces on the end)

From inside the barn (but outside the room) I climbed up the ladder on the top, and went to the wall above where the furnace was and filled in the wall with a couple cans of that expanding yellow foam insulation.

Then I went inside the workshiop and cut a rectangular hole in the wall (cut the drywall) a half-foot on the left of the furnace wall. I could see some of the yellow expanding foam had dropped all the way down here! So I filled in the open space with handfuls of dry wall insulation and sealed back the wall hole. Hopefully that will prevent any massive drafts from the squirrel.
 
 

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