Hey, It's Drafty in Here,...

I just happened to be checking the Dwyer model 25 manometer I have plumbed into the Glenwood range's stack. I noticed the red liquid is not lined up exactly with the middle of the wider, black zero mark. Since, over time the red liquid level can drop slightly, I check and re-zero it every several months.

After re-zeroing it back to the center of the wider zero line, I pulled the metal end tube out of the stack to check it's condition.
I happened to look at the gauge and the edge of the red line was no longer in the center of the black zero mark, but to the left edge of it. Just barely perceptible, but it did move.

I thought that maybe the liquid was just settling into it's new position. I put the tube end back into the stack and noticed that the red line was now back centered on the mark. To be doubly sure my eyes were not playing tricks, I got a large magnifying glass and watched the edge of the red line as I put the tube in and out of the stack several times. Sure enough, it was slowly dropping (moving left) when the tube was out and would slowly climb back whenever the tube was placed back into the stack (moving right). It moves equal to the width of one of the thinner black marks to the right of the wider zero mark.

I checked the outdoor temps verse indoor. It's 72 F in the kitchen and 64 F and very damp outside and no breeze at all. So, the stove and stack are warmer than the outside temps and the chimney.

This slight drop in pressure inside the stack shows that there is draft - very, very slight - but none the less, the warmer air from the house is causing a draft situation, pushing air through the slight air leakage the stove has when the dampers are closed and up through the chimney. Even against whatever natural stack-affect the house has.

This makes me wonder about the advise that if the stack is not disconnected, and/or, a light bulb is not put inside the stove to keep it warm and dried out, then colder, damp outside air comes down the chimney into the stove and corrodes it.

Once the stove is off for the summer I just vacuum it out and leave the stack connected - just closing all the stove's dampers and the mpd which still has some small holes built into it. In nine years of only doing that, I've not seen any evidence that the insides of this range are rusting. This gauge showing there is a natural updraft through the stove and chimney may explain why the stove has been spared from off-season corrosion ?

Has anyone else noticed similar results with their stove shut down ?

Paul

yes, as is known I have "atomic leaf blower" draft that pulls all yr. around.

the chimney thimble in the living room is 5' off the floor and I have 9' ceilings. I put an elbow in it facing up with 2 sections of smoke pipe and use it to exhaust the hottest air from the 1st floor all summer long.

the draft is not "very very slight" as you find in your install.

steve

I understand the light bulb in the stove for damp environments i.e. basements installations.

If I leave the smoke pipe connected I will get condensate which runs down the pipe and drips through the elbow connected to the stove.

If I leave smoke pipe standing vertically on brick hearth downstairs it will make a puddle on the floor. The cold pipe condenses the humid air.

Hey Paul, since I have an exterior chimney and it changes with the temperature outside, it will draft part of the day and then reverse for the other part of the day.. Leaving my pipe connected would be very bad for my furnace..

Chimney Draft Test

Yeah, I can see where the stack being down in the lower and cooler basement might cause downdraft.

Have you ever tried to see if the smoke gets pulled into the stove while it's still hooked up to the stack, with the dampers and mpd closed, and the baro open ?

If it does, then I'd block off the stack. If it doesn't than I wouldn't bother, . . . . . unless you also pull the stack to clean the fly ash out at the end of heating season - then it's a case of might as well.

Do you block off the stack when it's disconnected, or just leave it open ? I've had too many critters come down chimneys to ever want to just leave it open until the next heating season startup.

Paul

I totally disconnect the flue pipe, wash it out and store it in my attic thru the summer. My chimney is capped too, so no issues with nests. I leave the bottom open like you saw in the draft test thread. I'm wondering if letting it ventilate thru the summer would have any benefits.

franco b wrote:If I leave the smoke pipe connected I will get condensate which runs down the pipe and drips through the elbow connected to the stove.

If I leave smoke pipe standing vertically on brick hearth downstairs it will make a puddle on the floor. The cold pipe condenses the humid air.

I'm wondering if a chemical reaction with the fly ash is causing the condensation.. I see that happen on the interior of my furnace when I shut down for a few days..

Is the exterior of your pipe damp too? Or does the condensation seem to be coming from inside?

Lee,

No pests in the chimney, but you might wanna check that stove pipe for a new wasp nest before ya bring it down from the attic .

Paul

Lightning wrote:Is the exterior of your pipe damp too? Or does the condensation seem to be coming from inside?

Pipe surface seems dry. When connected to chimney I just assumed cold night air was causing condensation.
With the pipe standing on cold brick hearth and leaning at an angle there is evidently some air circulation through it. I was surprised to see a puddle.
In both cases the pipe had been brushed of loose fly ash.

I was going down the road in the bread truck when I started thinking about yer wet flue pipes..It's then that I remembered a similar thing with mine.. A few days after I shut down the furnace this spring, I remember seeing a puddle of water form at the bottom of my barometric damper door. The baro door and flue pipe were dry on the exterior.

Just thought I'd add that..

Looks awesome!! I'm sure you'll be more than satisfied with stout heating unit.
We expect a full report on our desk first thing ..... When it gets cold enough that is.

Geez...... This ended up in the wrong thread. Wtf. Sorry Paul