negative pressure trouble with new insert?

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intermediatic

Member
Oct 8, 2011
14
New Jersey
I'm the happy owner of a Morse 5660 insert (with blower) but I've got a problem.

I have a split level house on a hill. On the top is the main living space. We have the 5660 in the fireplace there, with a liner, "professionally installed," etc.

We also have a fireplace downstairs. While it feeds into the same masonry chimney, its a separate stack (there are three, one for the furnace, one for the downstairs, and one for the upstairs). When we removed the 1980s slammer Leyden insert from upstairs, I put in downstairs, figuring that we might use it a few times a year max (we used it once in the last month) and that if we lost power (it happens here), it'd be nice to have the source of heat. We never had any problems with the Leyden upstairs. But now, for whatever reason, to one side of it (by the stairs) smoke is accumulating. Before there were glass doors there. I didn't particularly appreciate them.

Any ideas? I'm thinking maybe that there is negative pressure being caused and that burning the Morso upstairs is making smoke accumulate downstairs as the smoke tries to find its way through the old insert, which is probably leakier than the old doors.

Haven't set the CO detecters off yet, but this isn't good is it?

Sadly, my installer isn't too sharp so I don't expect he'd be the fellow to turn to for this.

Or is there a problem with the liner he installed? It all looked good to me.

Our house is 20 years old and well built. During the sort of weather we've been having lately (WARM!) I could heat it with a match. Or rather not even. Once the sun's up, the large windows heat the house amply. That said, its 44 out. I've got a cold and I'd like some heat in here.
 
intermediatic said:
I'm the happy owner of a Morse 5660 insert (with blower) but I've got a problem.

I have a split level house on a hill. On the top is the main living space. We have the 5660 in the fireplace there, with a liner, "professionally installed," etc.

We also have a fireplace downstairs. While it feeds into the same masonry chimney, its a separate stack (there are three, one for the furnace, one for the downstairs, and one for the upstairs). When we removed the 1980s slammer Leyden insert from upstairs, I put in downstairs, figuring that we might use it a few times a year max (we used it once in the last month) and that if we lost power (it happens here), it'd be nice to have the source of heat. We never had any problems with the Leyden upstairs. But now, for whatever reason, to one side of it (by the stairs) smoke is accumulating. Before there were glass doors there. I didn't particularly appreciate them.

Any ideas? I'm thinking maybe that there is negative pressure being caused and that burning the Morso upstairs is making smoke accumulate downstairs as the smoke tries to find its way through the old insert, which is probably leakier than the old doors.

Haven't set the CO detecters off yet, but this isn't good is it?

Sadly, my installer isn't too sharp so I don't expect he'd be the fellow to turn to for this.

Or is there a problem with the liner he installed? It all looked good to me.

Our house is 20 years old and well built. During the sort of weather we've been having lately (WARM!) I could heat it with a match. Or rather not even. Once the sun's up, the large windows heat the house amply. That said, its 44 out. I've got a cold and I'd like some heat in here.
Open a window by the stove upstairs and downstairs... Crack a window
 
Oh wait a second… I think I get it.

There is negative pressure so air is rushing in down the chimney downstairs. Since the top of that stack is right next door to the top of the stack that's putting out smoke, it's sucking down smoke along with the air to the lower level.

Is that it?

It'd be a lot of money, but would I be better off with another modern insert like a second 5660 downstairs?
 
intermediatic said:
Oh wait a second… I think I get it.

There is negative pressure so air is rushing in down the chimney downstairs. Since the top of that stack is right next door to the top of the stack that's putting out smoke, it's sucking down smoke along with the air to the lower level.

Is that it?

It'd be a lot of money, but would I be better off with another modern insert like a second 5660 downstairs?

Let me know how you solve this, because i have the same issue - but only on relatively warm days and I light up, I will get smoke smell in my basement. When it is cold out, there is no smoke smell in my basement (I have my insert on the main floor and a regular fireplace in the basement). To solve the issue, I think I am going to put in a nat gas insert, but i first have to get permission from my boss (aka my wife).
 
How was this insert installed? Was a liner put in the chimney to connect the stove or was it just slammed in there?
 
You will have this problem no matter what stove is in there . How long is your chimney in the basement?
Is it an interior or exterior? I have the same problem and the key is to change pressure in the basement... Sometimes when its warmer I need to open window in basement and upstairs. When its cold just basement..
 
intermediatic said:
Oh wait a second… I think I get it.

There is negative pressure so air is rushing in down the chimney downstairs. Since the top of that stack is right next door to the top of the stack that's putting out smoke, it's sucking down smoke along with the air to the lower level.

Is that it?

It'd be a lot of money, but would I be better off with another modern insert like a second 5660 downstairs?

Let me guess, exterior masonry without liner in the "downstairs" chimney, and no damper. And warmer weather makes the problem worse?
 
I had the same problem whereas my fireplace from upstairs was throwing smoke down to the fireplace downstairs.
The way I tackled the fix was to offset the cap by factoring in an additional length of pipe (about 14") higher than the chimney cap next to it so now as the smoke drapes over the pipe it has too far to go to reach the flue next to it.
My Quadrafire chim pipe is between both of my other chim caps so it doesn't look that bad, However I don't have smoke downstairs anymore.
 
Ok, I tried the following today with success.

It is about five degrees colder now than it was yesterday, 30 instead of 35.

I built a top down fire. At the bottom I placed some kiln-dried firewood that still has some moisture in it (no choice there, unless I want to skip a season), maybe 15%. Atop it, some of my precious ancient grey wood that burns like crazy (one log per night will last me the season). Then half a fire starter. Atop that, slivers of kiln-dried that actually are dry. Around all of this, broken twigs and a couple of sheets of newspaper balled up. The twigs are touching the top of the chamber and stuffing the empty spots . Open upstairs door to outside a crack and ignite! After a few minutes the fire got pretty heavy and I had to close the door to the insert. The flame continued. Once the entire chamber was well engulfed, maybe 10 or 15 minutes into the burn, I closed the door to the outside. When the kindling was gone and the logs were going well, I turned down the intake to get the secondaries going.

This worked well. No smoke! My theory is that the smoke would get a real kick when, after the kindling had died down, I put on logs. In this case, the moisture left the logs while the fire was going so hot that it didn't significantly slow the draw. No smoke downstairs. It's now 10, the fan's kicked in a while back, the logs are coaling and I've had the heat off upstairs since 7:30 when I lit. We've got a wall of windows across the living room that this unit is in. I'm not trying to heat 24/7 with this unit, but I do want my evening fires to pay their own bills. That they're doing now!
 
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