New woodburning unit not giving off much heat - what am I doing wrong?

[Cincinnatux]

Hey, all. Just had a new BIS Tradition installed earlier this week and, after completing our break-in 'small fires' to cure the refractory brick panels, I fired it up for real today. I've fed it wood all day - a combination of oak, maple, and hickory (we live among 5 acres of the stuff), and all of the wood has had over a year to season. My wife and I are stunned that there is minimal heat coming out of the unit. When I open the doors to put a log in, heat floods out. Otherwise, it is mildly warm within about 5 feet of the unit. Beyond that distance you can see the flames and hear the (loud) fan blowing at full, but there is no warmth to be felt. We have a thermostat on the wall directly opposite (and facing) the BIS - about 15 feet away - and it registers 67 degrees. Since that is what we have our propane furnace set to (and it's been keeping the rest of the house at 67 or better), it would seem that the BIS is not sharing any of its heat with us yet.

I've attached two photos in the event there's key information missing from my description. As you can see from the photos, the unit has been installed but not finished. (We wanted to make sure the unit was fully functional before encasing it in stone.) It is sitting in a hole left by a defunct Mendota unit that had to be removed. In the second photo, my wife is standing as close as she can get to the BIS without feeling ANY heat. An old-school fireplace would have been much more effective at heating this room.

One other complicating factor: we have cathedral ceilings and have not (yet) turned on our ceiling fan. I realize that the ceiling fan will help us feel the heat, but I thought I'd be able to feel something within 6 or 7 feet of this beast. The BIS has been burning full-tilt for about 8 hours now. We have both gravity vents installed. It is possible to feel a meager amount of warmth (not enough to actually warm a chilled hand) about 2 or 3 inches away from the vent, but no further.

We can tell a slight difference when we turn the fan off, but the most noticeable change is that the BIS gets quiet. There's almost no detectable air blowing out of the unit even when the fan is on max.

So what did I screw up here? Is this something I can correct, or do I need the installer to schedule a visit?

Thanks in advance, and I hope everyone else is having a nice, wood-heated weekend!

- Michael "Cincinnatux" Sullivan

 

[iceman]

i am not a fan of running a fan on high turn it down a little higher than med.....
can you take a picture from the front? it looks like a gap at the top of the insert??

 

[begreen]

Agreed, lower the fan speed. What is the air control setting? Too much air may cool the fire. Once the fire is hot, it should be set to medium or a bit lower to encourage a hot secondary burn.

Can you describe how the forced air system is set up? Where is the BIS taking in the intake air for the fan? From the description it almost sounds like the intake is blocked.

Also, before turning on the ceiling fan, bring in a ladder and take the temperature at 12 feet.

 

[Cincinnatux]

Thanks for the quick responses. The gap you see in the photo is not an optical illusion. The BIS Tradition has a decorative grill plate that surrounds the front of the unit; we have not had this decorative element installed yet because it's supposed to go on after the stone work has been completed. Thus, there are gaps above and below the hearth doors, and the Tradition's blower is supposed to push air through those gaps.

As an update, the thermostat across the room now reads at 71 degrees, so maybe there's progress here. I have put the fan at the medium setting. Thanks again for the responses. Any clue why the fan seems so weak or why the gravity vents don't seem to be emitting much warmth?

 

[BrowningBAR]

Thanks for the quick responses. The gap you see in the photo is not an optical illusion. The BIS Tradition has a decorative grill plate that surrounds the front of the unit; we have not had this decorative element installed yet because it's supposed to go on after the stone work has been completed. Thus, there are gaps above and below the hearth doors, and the Tradition's blower is supposed to push air through those gaps.

As an update, the thermostat across the room now reads at 71 degrees, so maybe there's progress here. I have put the fan at the medium setting. Thanks again for the responses. Any clue why the fan seems so weak or why the gravity vents don't seem to be emitting much warmth?

There's a guy on this forum that owns a BIS Ultra. Hopefully he'll chime in and give you some insight as to the installation/workings/setup of the stove.

 

[EatenByLimestone]

Can you look and see if the installer put a block off plate in so heat can not go up the chimney?


Matt

 

[begreen]

Thanks for the quick responses. The gap you see in the photo is not an optical illusion. The BIS Tradition has a decorative grill plate that surrounds the front of the unit; we have not had this decorative element installed yet because it's supposed to go on after the stone work has been completed. Thus, there are gaps above and below the hearth doors, and the Tradition's blower is supposed to push air through those gaps.

As an update, the thermostat across the room now reads at 71 degrees, so maybe there's progress here. I have put the fan at the medium setting. Thanks again for the responses. Any clue why the fan seems so weak or why the gravity vents don't seem to be emitting much warmth?

If installed correctly, the gravity feed output vents are high. They should be hot. However, that is putting the heat where you don't need it, up in the peak of the cathedral ceiling. Turn on the ceiling fan on low speed, in reverse if possible so that it blows upward.

 

[Cincinnatux]

Agreed, lower the fan speed. What is the air control setting? Too much air may cool the fire. Once the fire is hot, it should be set to medium or a bit lower to encourage a hot secondary burn.

Can you describe how the forced air system is set up? Where is the BIS taking in the intake air for the fan? From the description it almost sounds like the intake is blocked.

Also, before turning on the ceiling fan, bring in a ladder and take the temperature at 12 feet.

The air control setting is fully open (and the air boost has been shut off, since that's only supposed to be on during a cold start).

The BIS Tradition's blower has a 120V motor in the back of the unit at the bottom. There is a forced air kit option, but we did not want to connect our unit to our central air ducting system - the house is too big to demand that the BIS heat the whole place. We have an open plan house, and the kitchen, dining room, living room, and an office are partitioned without being closed off.

I do not think the intake could be blocked, really. It should be able to draw from the entire underneath of the unit (that gap across the bottom of the unit should be feeding the blower. It looks clear all the way to the back. Thanks for the suggestion, though; it got me to look.

 

[KarlP]

The air control setting is fully open

Once the stove gets hot, try everything between 1/3 to 1/8th open. Something in there will probably give you the most heat.

 

[begreen]

Yes, reduce air supply to medium setting or lower until the flames just start to get lazy. Turn on the ceiling fan. As cold as it is in Ohio, it may take a little time to feel the changes. Don't be surprised if it takes a lot of fuel to keep the place warm during this period. But don't over feed the stove either.

 

[Cincinnatux]

Thanks to all for the help. With the air intake adjusted, I'm getting steady heat in the space and I was able to relight a fire from the coals still burning this morning, no kindling needed. The BIS is definitely giving off more heat today than it did yesterday. I'm still pretty disappointed in the gravity vents, though. They have thus far proven useless and give off about 1 candle of heat per vent, not enough to warm a closet let alone a dining room. Anyone out there have a BIS tradition with gravity vents that do anything?

 

[cdnxj]

I have an older Security BIS 1.0 very similar setup to yours. I have double gravity hot air vents with a dual fan mounted under the unit, blows air under, through, and out the vents. They get HOT to the touch, can get over 200 degrees F. So something is definitely wrong. That's where you should be getting the most heat from these stoves.

Are you sure the block off plates got removed when the gravity piping was installed? No other obstructions?

 

[MogollonMonster]

I have tall cathedral ceilings in my home too. I was running two ceiling fans at low speed on reverse. My Oslo didn't seem to heat the room very well. I put a thermometer up high on a shelf (12' high) and it was reading 80°F+. At floor level I could only get the temp to about 70 °F. I put the both ceiling fans on medium speed, one in reverse and one not. This really mixed the air in the room very well and I can warm the room to 77 °F. The room I heat is about 30'x40' with 18' ceilings and with the fans running is fairly uniform in temperature.

 

[begreen]

Are the upper gravity vent pipes heading uphill all the way to the vent or are there some 90s in there? Pictures or a simple diagram would help.

 

[par0thead151]

i too have tall ceilings.

i found that putting a fan on the ground and blowing cold air up works the best.
i have a steel framed fan that sits a foot or more off the floor and can be aimed straight up.
it works like a charm.

as far as your stove not making much heat, is your wood seasoned?, do you have a block off plate?
how is the homes insulation?
is there snow on your roof? if not you have massive heat loss through the ceiling and roof area. more insulation in the attic can fix that.

 

[fire_man]

I have tall cathedral ceilings in my home too. I was running two ceiling fans at low speed on reverse. My Oslo didn't seem to heat the room very well. I put a thermometer up high on a shelf (12' high) and it was reading 80°F+. At floor level I could only get the temp to about 70 °F. I put the both ceiling fans on medium speed, one in reverse and one not. This really mixed the air in the room very well and I can warm the room to 77 °F. The room I heat is about 30'x40' with 18' ceilings and with the fans running is fairly uniform in temperature.

I have a tall cathedral ceiling in a 20' X 22' room and measured a 10 degree difference between the ceiling and floor. I turned on the ceiling fan (low setting , reversed) and even though the air mixed and warmed the bottom area, everyone complained it felt cooler due to the moving air. I wish it worked for me! :-/

 

[Cincinnatux]

I have an older Security BIS 1.0 very similar setup to yours. I have double gravity hot air vents with a dual fan mounted under the unit, blows air under, through, and out the vents. They get HOT to the touch, can get over 200 degrees F. So something is definitely wrong. That's where you should be getting the most heat from these stoves.

Are you sure the block off plates got removed when the gravity piping was installed? No other obstructions?

Thanks for the heads-up; I do not know with certainty that the plates were removed. I'll be sure to talk to the installer about the gravity vents on Monday and I'll ask about this. Is there a way for me to see whether those plates are still attached? It seems I'd have to remove a gravity vent duct to confirm; is that the case?

 

[Cincinnatux]

Are the upper gravity vent pipes heading uphill all the way to the vent or are there some 90s in there? Pictures or a simple diagram would help.

The gravity vents face to the rear of the unit, mounted on short ducting that looks like giant elbow macaroni, with insulation wrapped around each duct. The unit is mounted against an interior wall, and there is a dining room on the other side of that wall. The vents are about 2 feet above the top of the stove; they are not feeding a second floor room; the rooms are on the same floor and are separated by a 6-inch uninsulated wall. Sorry I don't have any photos that can illustrate this configuration.

 

[Roxburyeric]

I also have a large family room with cathedral ceiling and an insert stove. You must use a ceiling fan - I don't think it makes a big difference which way the fan turns as long as it is mixing the air. The upper heights do get the most heat. When the stove is burning good or very good you can really feel the heat coming out of the blower within a foot or so of the stove. You won't feel a blast of heat much further back. The draft from the ceiling fan will feel cool some times and warmer others - depending on how hot your stove is running. Sounds like you are trying to heat a large house with a stove designed for a normal house (like me). So you will need to really push the stove to get a good amount of heat out of it. With the high ceiling I don't think you will ever get the temps in the room that others here get with shorter ceilings. My stove will let me hold a temp in the house without the furnace - but not bring it higher when it is colder than 20 or so outside. If you have an open staircase and rooms looking down into the family room with the cathedral ceiling you will need to keep the doors mostly closed upstairs or all the heat will go into the rooms and not come back down to the first floor level. Good luck - sounds like you are figuring it out.

 

[Cincinnatux]

General update:

During the day yesterday, by following the advice above, we were able to heat our main living area to 72 degrees for most of the day; it was about 20 degrees outside and we have a good 4 inches of snow on the roof. Our home is 20 years old and has insulation typical of homes built in the late '80s and early '90s, which is to say 'not great.' The house envelope is leaky, and one of our projects for the next year will be to re-insulate the attic (blown cellulose that has to cover sloped areas, meaning that it is difficult to keep an even layer of cellulose across the attic space). The room that the BIS is in measures 17' by 30' and has a cathedral ceiling that peaks at 20'. There are two skylights and one ceiling fan. This room shares the cathedral-area airspace with an office, a dining room, and a kitchen, but there are divider walls (about 9' high) that retard the flow of air at person-level (hence the use of gravity vents to try to get some heat on the other side of one of the divider walls. Total square footage is about 1400 sq ft, but the cathedral ceilings add a lot of cubic footage of air that needs to be heated along with the air down at person-level.

As I said above, the BIS heated the main area (the 17x30 area) up to 72 degrees and kept the attached rooms (both with and without the gravity vents) at about 66 degrees. We consider this a win - it is what we wanted. But I was hoping the gravity vents would have kept our dining room a little warmer. At 66 degrees, it is not a cozy place to hang out with guests, as we discovered last night with a dinner we hosted.

The key downside thus far is that the house is pretty chilly in the morning, until the BIS has a few hours to warm the place up again. We're up to 63 degrees at 9am, but it will probably be noon before the main room is up to 70 and the other rooms get up to 65. By afternoon and evening, of course, all is cozy!

 

[moosetrek]

Given the size you're looking to heat, especially with 20' ceilings, I think you're doing well-