M55 - disappointing results

[martinstove]

Hello there,

I installed an M55 insert in my home yesterday and unfortunately the results were not what I was hoping for. Not even close actually.

Details:

• house is in MD, ~5,000 sq ft, 2,500 per floor, 100 years old, leaky, minimal insulation.
• 30ft 4in vent through chimney (13x13 clay flue liner). No OAK. Burning Turman pellets. Stove is in Kitchen, on one end of long, narrow rectangular house.

I have had the stove cranking on setting 3 to 5 for over 5 hours today and the kitchen is only 66 deg. It's only 54 deg outside.

I don't have a mag gauge or a temp probe but i do have an infrared thermometer - it registers ~340 max at the blower baffles.

The flame looks good and the unit seems to be putting out some hot air. But the room temperature just isn't rising. I thought the stove would get the kitchen up in the 80's and 90's in this mild weather.

So here's my thought - is the blower so strong that it's sucking in cold air from outside (through windows/doors/etc.)? If so, would an OAK fix this? Or does the OAK only feed the fire and not the blower? I was advised that because I had a leaky house, I didn't need an OAK. [btw, if someone can direct me to a flue liner adapter that houses both the vent and OAK, that would be great. Thinking only way to get OAK is same as vent - through chimney]

I have a little [fake] smoke machine and I can see that tons of air is being sucked into the room from the leaky basement door (unconditioned basement) as well as through other 'inlet' areas (doors/small holes in floor, etc.).

I really hope there's an easy fix to this. The 1 steam radiator in the room puts out about 15,000 BTUs and makes the room much warmer than this 55k btu stove on 5! Of course the radiator doesn't suck in any air.

Would be very appreciative if anyone has any ideas or suggestions. Right now I feel like I wasted a lot of time and money on this beast.

Thank you

 

[Lake Girl]

Welcome to the forum. Beautiful looking insert... Was this a self-install or dealer? Set up with a mag?

The manual "strongly recommends" an OAK. Is there a clean-out to the exterior for the fireplace that you could use to run it out?

An OAK feeds combustion only. Without an OAK, you are pulling pre-warmed air from the living space to feed combustion and then throwing that air out the exhaust vent. Since air used for combustion must be replaced in the living space, it is pulling cold air through the building envelope to feed that need. The convection blower uses room air to push air through the heat exchangers to warm that air. An OAK should have been installed but you need to insulate too.

Big house to heat.... It won't do it alone.

 

[martinstove]

Welcome to the forum. Beautiful looking insert... Was this a self-install or dealer? Set up with a mag?

The manual "strongly recommends" an OAK. Is there a clean-out to the exterior for the fireplace that you could use to run it out?

An OAK feeds combustion only. Without an OAK, you are pulling pre-warmed air from the living space to feed combustion and then throwing that air out the exhaust vent. Since air used for combustion must be replaced in the living space, it is pulling cold air through the building envelope to feed that need. The convection blower uses room air to push air through the heat exchangers to warm that air. An OAK should have been installed but you need to insulate too.

Big house to heat.... It won't do it alone.

Thanks for the reply.

I installed the unit on the inside and a stonemason ran the vent/terminated at the top of the chimney. Was not setup with a Mag yet. Only way to do an OAK without altering the fireplace would be to go up and out the chimney, same as the vent. I am trying to leave the fireplace 100% in tact.

Since the OAK only feeds the fire and not the blower - in this case I don't think it would help that much. I'm guessing the blower pulls a lot more air than the combustion chamber?? Actually, when I first ran the stove, the blower wouldn't turn on. I kept getting a #3 errors before I realized the blower wasn't even turning on (i'm new to stoves). So I pulled the unit out and saw that the 2 wires that attach to [i think] the exhaust sensor weren't connected. Hooked them up and blower came on strong.

I was hoping to heat only 2-3 rooms with the stove, less than 1,000 sq ft. At this point, I can't even get 1 room hot when it's 56 degrees outside.

I will call the dealer and see if they'll come out to tune the stove. But was hoping the experts here would have some suggestions since my results seem outside the norm.

 

[Lake Girl]

That air that is being sucked into the room feeds the combustion blower and gets thrown out the vent. It will keep on pulling cold air into your living space to replace what it uses unless you use an OAK. Figure out how to install the OAK... then the only air that will be moving inside your home will be air that will be getting heated.

 

[TCZON]

My Drolet manual shows that an OAK can be installed into a ventilated crawl space, I would imagine your basment would qualify. Is there a way to put a hole down to the basement to run the OAK?

We don't have an OAK,*but* the stove is actually right beside the cold air return for the furnace, and if we really felt the need, we would just run it down through that grating. It hasn't been an issue for us though.

 

[Lake Girl]

If the boiler system the OP is using to heat the house is not direct vented, it is also pulling air from the basement for combustion. In competing for air, it could cause a negative pressure situation.

 

[Hoot23]

I would like to OAK my in-laws stove that I hooked up yesterday and the only way to do that is at the top of the chimney. There is no clean out and my mother-in-law is against drilling through the back of the chimney. I was thinking of drilling a hole beside the 4" vent and then come up with 2 90's and make a U shape so it was pointing down and not getting any exhaust.

 

[dradam1]

Just a question??...
Do you have the 13 x 13 flu liner blocked off (block off plate/ insulation )? Since you have your 4" going thru it and can no longer use a damper. That would suck lots of heat out.

 

[Bill L]

I think that oak or no oak, with outside temps at 54 you should still be able to get the stove room up to a much higher temp, especially running on 5. Are you sure the flame is proper size? I installed my insert a year ago February. The skytech thermostat was ordered, but came a week after the install. I had a heck of a time getting heat from the stove for the first week due to an issue with the hopper lid switch magnet skimming the thermostat switch. Every time I shut the lid, it would push the thermostat switch to on/off, and since there was no thermostat installed, it would drop to low after the initial start up. I would open the hopper lid and it would drag the switch back to manual, so I had no idea what was wrong. A week later, the dealer installed the thermostat, and the stove started burning normally because I had the temp set. I also had them open the hopper feed plate a little, as I had done a little research and thought that May have been the problem. I actually didn't figure out it was the switch issue until December this year, after the stove would shut down by itself when I knew it was in hi/lo. You can check if this is happening by shutting the lid, then opening it while lifting it up a bit. Outside chance this may be your problem, the dealer said enviro had never heard of this issue, but I find it hard to believe I'm the only one.

 

[martinstove]

That air that is being sucked into the room feeds the combustion blower and gets thrown out the vent. It will keep on pulling cold air into your living space to replace what it uses unless you use an OAK. Figure out how to install the OAK... then the only air that will be moving inside your home will be air that will be getting heated.

Question - even if I can install an OAK, won't the blower still be sucking in lots of air, which will suck in cold air from outside?

 

[martinstove]

Just a question??...
Do you have the 13 x 13 flu liner blocked off (block off plate/ insulation )? Since you have your 4" going thru it and can no longer use a damper. That would suck lots of heat out.

No, I didn't block off the flu liner. I removed [pushed wide open] the damper, and ran the vent past the old heatilator style heat tubes/baffles, past the open damper and then up to the top of the chimney (lined all the way up with 13x13 clay tile) and out the top. Used a kit like this one: http://www.firesidechimneysupply.co...x-316ti-basic-flexible-chimney-liner-kit.html

 

[stovelark]

Good writeup Bill, yes I've had to adjust the top lid on 2 M55's myself that was scraping/changing slide switch. I hate to say this, but I've heard that line from Enviro on a couple of issues. Maybe they don't know all either but is frustrating.
If the house is leaky, don't imagine any stove will be able to keep up with an "open" house. House sounds very large too, it will be difficult to heat that large of an area. OAK will benefit the effort though. Good luck with that.

 

[martinstove]

I think that oak or no oak, with outside temps at 54 you should still be able to get the stove room up to a much higher temp, especially running on 5. Are you sure the flame is proper size? I installed my insert a year ago February. The skytech thermostat was ordered, but came a week after the install. I had a heck of a time getting heat from the stove for the first week due to an issue with the hopper lid switch magnet skimming the thermostat switch. Every time I shut the lid, it would push the thermostat switch to on/off, and since there was no thermostat installed, it would drop to low after the initial start up. I would open the hopper lid and it would drag the switch back to manual, so I had no idea what was wrong. A week later, the dealer installed the thermostat, and the stove started burning normally because I had the temp set. I also had them open the hopper feed plate a little, as I had done a little research and thought that May have been the problem. I actually didn't figure out it was the switch issue until December this year, after the stove would shut down by itself when I knew it was in hi/lo. You can check if this is happening by shutting the lid, then opening it while lifting it up a bit. Outside chance this may be your problem, the dealer said enviro had never heard of this issue, but I find it hard to believe I'm the only one.

Interesting issue you had. I don't think this is happening on mine. Stove appears to be working correctly. I also have a Skytech wireless remote. I programmed it, and everything seems to be working correctly (turns on/off at correct time, etc). Only problem is, the room doesn't get hot! Flame looks pretty good. Not as big as some of the videos I've seen, but decent. The air it's blowing out is hot. And my infrared thermometer gets temps as high as 340-350f in the tubes. But once I get just a few feet from the stove, it feels more like a room temperature breeze than hot air.

I'm attaching a picture from this morning, on Setting 5. [smoke stains on stone above stove are old and unrelated to the stove].

 

[Jack Morrissey]

5000sq ft? W/little or no insulation.... I would think its going to take more than 3-5 hours to get your house hot, even if its 60 outside!!

 

[dradam1]

No, I didn't block off the flu liner. I removed [pushed wide open] the damper, and ran the vent past the old heatilator style heat tubes/baffles, past the open damper and then up to the top of the chimney (lined all the way up with 13x13 clay tile) and out the top. Used a kit like this one: http://www.firesidechimneysupply.co...x-316ti-basic-flexible-chimney-liner-kit.html

If your 13 x 13 flu is going to daylight except for the 4" diameter liner, I would suspect lots of heat would be drafting out of your house. Kind of like keeping your old damper open when you didn't have a fire (less 4" dia.).

 

[Luv2burnPellets]

Question - even if I can install an OAK, won't the blower still be sucking in lots of air, which will suck in cold air from outside?

No. The OAK suppies combustion air only. The distribution blower you are referring to merely circulates the hot air produced by the stove, in theory. Unless it can suck in cold air from an open chimney in close proximity to the fireplace.

 

[martinstove]

large

5000sq ft? W/little or no insulation.... I would think its going to take more than 3-5 hours to get your house hot, even if its 60 outside!!

Yes, R19 in the attic, but that's about it for insulation. House is stone and stucco with plaster walls.

Not looking to heat the entire home, only the 1 room where the stove is located and the 2 rooms next to it. Maybe 1,000 sq ft.

 

[martinstove]

If your 13 x 13 flu is going to daylight except for the 4" diameter liner, I would suspect lots of heat would be drafting out of your house. Kind of like keeping your old damper open when you didn't have a fire (less 4" dia.).

I had a similar thought, but how would the heat be exiting the house? The top of the 13x13 flu is capped off and sealed with some sort of silicon/adhesive. Only penetration is the 4in vent (but that's sealed to the stove on the bottom). Had chimney swept recently and a camera inspection showed all flu tiles were in tact and in good condition.

I can see how air would have gotten out previously when the damper was open (because nothing was sealed off at the top), but now even though the damper is open, the top of the flu is sealed off.

 

[MountainSean]

Even without a draft going up the chimney if it is capped off, you will be losing a lot of heat up the chimney as the stove tries to heat up that chimney, and masonry is a heat sponge. Add in that you see air being pulled up from the basement, which means you will be pulling air up that is 15 degrees cooler than the room you are heating .

To sound like the others. Get an OAK, and put a seal above the stove in the chimney and you will be amazed at how much warmer your stove will make the room. As it stands right now you are trying to do little better than setting your stove outside and asking it to heat the 1,000 sq ft around it.

 

[martinstove]

No. The OAK suppies combustion air only. The distribution blower you are referring to merely circulates the hot air produced by the stove, in theory. Unless it can suck in cold air from an open chimney in close proximity to the fireplace.

My running theory is both the combustion chamber and distribution fan are sucking cold air into the room - from both the basement and outside. I wonder if I supply the combustion chamber with an OAK, will I continue to have the same issue since the circulation fan is still sucking in cold air into the room.

Have a call into the dealer, but haven't heard back yet. I might try to seal off some of the 'obvious' leaks near the stove [ex, 2 in clearance under basement door 15ft away, some holes where old plumbing/electrical used to run 20ft away, etc.]. Sealing off the chimney near the damper will be more difficult and I'm not sure this would make much difference as the top of the flu is already sealed off.

Thank you everyone for your suggestions.

 

[MountainSean]

My running theory is both the combustion chamber and distribution fan are sucking cold air into the room - from both the basement and outside. I wonder if I supply the combustion chamber with an OAK, will I continue to have the same issue since the circulation fan is still sucking in cold air into the room.

Have a call into the dealer, but haven't heard back yet. I might try to seal off some of the 'obvious' leaks near the stove [ex, 2 in clearance under basement door 15ft away, some holes where old plumbing/electrical used to run 20ft away, etc.]. Sealing off the chimney near the damper will be more difficult and I'm not sure this would make much difference as the top of the flu is already sealed off.

Thank you everyone for your suggestions.

Your convection/circulation fan is just moving air around the house. Takes air from your kitchen heats it up and puts it right back into the kitchen, zero heat loss. Your combustion fan though is moving upwards of 80 cubic feet per minute of air from your house, heating it up and throwing it right outside where it does you no good. With a lot of air leaks into the house right by the stove, there is little time for the stove to heat the air before it is evacuated outside and replaced by the colder air from outside that is getting in from all your leaks. Your plans to plug some of those holes and the opening to the basement will help.

 

[martinstove]

Even without a draft going up the chimney if it is capped off, you will be losing a lot of heat up the chimney as the stove tries to heat up that chimney, and masonry is a heat sponge. Add in that you see air being pulled up from the basement, which means you will be pulling air up that is 15 degrees cooler than the room you are heating .

To sound like the others. Get an OAK, and put a seal above the stove in the chimney and you will be amazed at how much warmer your stove will make the room. As it stands right now you are trying to do little better than setting your stove outside and asking it to heat the 1,000 sq ft around it.

I like your analogy - the stove right now feels about as effective as it would had I just put it outside!

I think there are 2 options for OAK without altering the fireplace (which I want to avoid). 1. Go up and out chimney just like vent (are there caps made for this that house both the 4in vent and the 3 in OAK? I remember seeing these a while back in my research but can't find them now. Or 2. See if it's possible to go down into the basement - think this might not be practical/possible.

Any suggestions on sealing above the stove in the chimney?

Thank you again.

 

[Lake Girl]

Something else no one has mentioned - Do you have surge protection on the stove cord?

 

[Jags]

Sealing off the chimney near the damper will be more difficult and I'm not sure this would make much difference as the top of the flu is already sealed off.

I would like a piece of this bet. It is VERY common whether pellet or wood for a large masonry chimney to be a giant heat sponge. Install a block off plate and keep the heated air in the room.

 

[martinstove]

Something else no one has mentioned - Do you have surge protection on the stove cord?

Not yet - just have it temporarily plugged into a 12 gauge heavy duty extension cord.

Your convection/circulation fan is just moving air around the house. Takes air from your kitchen heats it up and puts it right back into the kitchen, zero heat loss. Your combustion fan though is moving upwards of 80 cubic feet per minute of air from your house, heating it up and throwing it right outside where it does you no good. With a lot of air leaks into the house right by the stove, there is little time for the stove to heat the air before it is evacuated outside and replaced by the colder air from outside that is getting in from all your leaks. Your plans to plug some of those holes and the opening to the basement will help.

I see. In that case, if the circulation blower doesn't really suck in cold air from outside, then it sounds like the OAK would prevent all of the cold air from entering the room/house.

I read a bunch of threads about OAK vs no OAK. Seems like people are passionate about this debate for some reason. Was told that since my house was old and leaky, it wasn't necessary. Guess I underestimated just how much air the stove requires. Figured the 'natural' rate of leakiness in the house would supply the fire with whatever it needed.

Had a blower door test done a while back and was told the 'optimum' level of leakiness was ~4 or 5,000 cfm and my house was at 11,000cfm.