Kuuma owners, report!

[brenndatomu]

Curious how many of you actually have your thermostat hooked up, and actually use it? Especially you guys with larger homes...and also for the same people, how often do you need to turn the burn rate (computer) up from low...and how far...ever 100%?

 

[JRHAWK9]

Had it hooked up originally and used it for a little bit at first. I didn't really notice any change in the furnace's ability to heat our house, so I pretty much stopped using it. I unhooked it when I went to the variable blower speed control setup and have not looked back. Now it automatically speeds up the blower as plenum temps rise and automatically slows the blower down when temps fall. Seeing I have an adjustable ohm pot skewing the resistance the speed control module sees, I am able to speed up and slow down my blower as I see fit. Playing around with this the more I slowed the blower down, the higher my supply temps went and the better the house heated. The original blower was a bushing motor, so I could only slow it down so far before the RPM's were too slow at blower kick-off to keep the bushing sleeves happy long term. I felt I still had more to gain by slowing it down even more, so I swapped in a ball bearing motor. I now have it running pretty darn slow at blower kick-off.

As far as the computer. I pretty much leave it on low till we get temps which consistently drop near zero. Weathering a single nightly low of around 0° with the Kuuma on low is not an issue when the next day is decent, I've done numerous single digit below zero nights already this winter but the next day always got up near 20°+/-. If the house loses some temp by morning (say 68°), no biggie, can always catch up during the day. It's the night after night after night after night of below zero temps with no real warm-up during the day is what's challenging for this house. That's when I turn it up and let 'er eat.

 

[woodey]

I have my thermostat hooked up but rarely ever use it. That being said in the recent cold snap we just had (nights 10-15 below and daytime highs in the single digits with wind) I played around with the thermostat. I set it at 70 and it worked great alternating from high /low occasionally off. I still think I like the constant low side the best. As far as the computer I leave it on low 85 % of the time. With the above temps I would set the computer up to about 1/2 way between low and medium at nite and single digits day temps would run at medium. The only time I run it on high is in coldest temps the last 2-3 hours of the burn to get the heat from the remaining coals.

 

[JRHAWK9]

I have my thermostat hooked up but rarely ever use it. That being said in the recent cold snap we just had (nights 10-15 below and daytime highs in the single digits with wind) I played around with the thermostat. I set it at 70 and it worked great alternating from high /low occasionally off. I still think I like the constant low side the best. As far as the computer I leave it on low 85 % of the time. With the above temps I would set the computer up to about 1/2 way between low and medium at nite and single digits day temps would run at medium. The only time I run it on high is in coldest temps the last 2-3 hours of the burn to get the heat from the remaining coals.

IIRC, aren't you heating a decent sized house too? That's impressive!

 

[burtman4]

I was using my thermostat untill a week or so ago. I had it set on 72 since I installed the furnace in 2017. Had a day recently where I let the fire burn down too far the night before, the house was 68 degrees and the wife was cold. I loaded with wood, turned the heat all the way up and waited. Outside temps were in the 20's with a 20 -25 mph NW wind. It was one of those days that really takes the heat out of my house. The house temp was rising slowly and after 4-5 hours it was 70-71. I remember reading that a lot of you don't have your thermostat hooked up, so I turned mine down so the blower would only run on low just to see what happens. After a few hours house temp was up to 73 degrees. I found for what ever reason, it was heating better with the blower on low. I also had a more uniform temp in the house, which I did expect. Since then I have left the thermostat at 60 to keep the blower on low and it does seem to heat better. I do turn the heat dial up on the Kuuma in the cold winter when it won't keep the house warm on low. My house is a 1900 sq. ft rancher with a full basement, so I am heating almost 3800 sq ft. My basement is a walk out , and about half of the front part of the basement is exposed, so there is a lot of surface area which see's the outdoor temps. I haven't had a day when the Kuuma wouldn't keep the house warm, but I have had it packed full of oak and turned up on high to keep the temp I wanted.

I may be picking JRHAWK9's brain after heating season on the variable speed blower setup, after seeing how things worked just heating with the blower on low speed.

 

[woodey]

IIRC, aren't you heating a decent sized house too? That's impressive!

Yes, a large 155 year old house. I would be lying if I said I didn't get help from the propane furnace on occasion. As stated above, running on medium in single digits during the day the house stays at about 68 which is comfortable for me. I set the propane at 67 and it might cycle on a few times an hour the last 2 hours of the burn. The same in the mornings after a sub zero nite. The 2 units work good in conjunction with each other. When the propane blower kicks in it doesn't run very long as it also blows the heat from the jacket and plenum from the wood furnace. I would guess in a average winter the Kuuma supplies about 95% of the heat.

 

[brenndatomu]

As stated above, running on medium in single digits during the day the house stays at about 68 which is comfortable for me. I set the propane at 67 and it might cycle on a few times an hour the last 2 hours of the burn. The same in the mornings after a sub zero nite. The 2 units work good in conjunction with each other. When the propane blower kicks in it doesn't run very long as it also blows the heat from the jacket and plenum from the wood furnace.

Nice!
I think being able to run both together, so that the fossil fueled furnace can bat clean up, so to speak, in the wee hours of the morning, or at the end of a long workday, should be the goal when people are doing a new install.
I should be able to run mine in this manner too, but I haven't actually tried it yet...need to wire in a lockout relay for the Kuuma blower to do it...honestly, for our house, its not really needed since the Kuuma will carry the load all on its own...but its nice to have options!

 

[woodey]

Nice!
I think being able to run both together, so that the fossil fueled furnace can bat clean up, so to speak, in the wee hours of the morning, or at the end of a long workday, should be the goal when people are doing a new install.
I should be able to run mine in this manner too, but I haven't actually tried it yet...need to wire in a lockout relay for the Kuuma blower to do it...honestly, for our house, its not really needed since the Kuuma will carry the load all on its own...but its nice to have options!

 

[woodey]

[QUOTE="woodey, post: 2494713, member: 59674

The above picture is how the relays for the thermostats are wired. Probably could have been done with one switch but he only had a single one at the time of install so came back later and put on the other taking care of both the high and low of the Kuuma blower.

 

[garmford]

Thanks to jrhawk I’m also running the variable speed blower set up and has helped a ton. We heat a 2300 sq’ ranch. So far this season we’ve had many below 0 mornings, -11 was the coldest, and quite a few single digit mornings too. Those days it at least got into the teens so all was good. Loaded twice a day and the house stayed anywhere from 71-76* with the computer never leaving the low setting. IIRC that -11 morning we dropped to 68. Not bad in my eyes.

We have a cold week ahead of us with highs in the single digits. Unfortunately I know I’ll need to turn the dial up on the computer and go to a 3 load/day cycle. Probably will need to let the LP furnace cycle a few times too. I’m ok with that.

 

[brenndatomu]

I'll pass on a little nugget of info that I learned from Dale Friday...I've never heard this before...it needs to be in the operational instructions somewhere @lampmfg ...decals on the front, manual, website, (all) somewheres.
But Dale said that he himself just learned this from Daryl very recently...anyways, that it is important to load the wood so it is about 1" from the front face, at least on the bottom row or two...hot coals still back at least 2" away, as always...this is supposed to help get the fire started hotter/quicker/cleaner...and I have been doing this since Friday, it makes a noticeable difference, and I generally cut to 20", so its not like I was loading wood 6" away!

 

[woodey]

I'll pass on a little nugget of info that I learned from Dale Friday...I've never heard this before...it needs to be in the operational instructions somewhere @lampmfg ...decals on the front, manual, website, (all) somewheres.
But Dale said that he himself just learned this from Daryl very recently...anyways, that it is important to load the wood so it is about 1" from the front face, at least on the bottom row or two...hot coals still back at least 2" away, as always...this is supposed to help get the fire started hotter/quicker/cleaner...and I have been doing this since Friday, it makes a noticeable difference, and I generally cut to 20", so its not like I was loading wood 6" away!

Thanks for the heads up, while I always keep the coals 2" back I will make sure to place the shorter pieces 1" back as I got a good buy on a full cord of seasoned 16" wood. When you mentioned decals on the front that got me thinking that I need the new Kuuma emblem on the hood of my furnace to complete my install. If lampmfg is willing to sell one they can contact me thru conversations with details.

 

[lampmfg]

Thanks for the heads up, while I always keep the coals 2" back I will make sure to place the shorter pieces 1" back as I got a good buy on a full cord of seasoned 16" wood. When you mentioned decals on the front that got me thinking that I need the new Kuuma emblem on the hood of my furnace to complete my install. If lampmfg is willing to sell one they can contact me thru conversations with details.

Just send us an e-mail and we will get you one.

 

[woodey]

Yes, a large 155 year old house. I would be lying if I said I didn't get help from the propane furnace on occasion. As stated above, running on medium in single digits during the day the house stays at about 68 which is comfortable for me. I set the propane at 67 and it might cycle on a few times an hour the last 2 hours of the burn. The same in the mornings after a sub zero nite. The 2 units work good in conjunction with each other. When the propane blower kicks in it doesn't run very long as it also blows the heat from the jacket and plenum from the wood furnace. I would guess in a average winter the Kuuma supplies about 95% of the heat.

At 8 this morning we were at 10 below, I loaded the Kuuma with three 20" splits and set the computer just slightly over medium. Now two hours later with temps at 2 below and blower on low the old house holding at a steady and comfortable 68.

 

[brenndatomu]

At 8 this morning we were at 10 below, I loaded the Kuuma with three 20" splits and set the computer just slightly over medium. Now two hours later with temps at 2 below and blower on low the old house holding at a steady and comfortable 68.

That's impressive...about the only time I can heat with 3 splits is early fall or late spring!

 

[woodey]

Obviously with the computer set higher than usual and by loading only 3 splits I will reload sooner, but as we all know it avoids the delay in letting the coals die down for a quicker reload in these temps.

 

[RockyMtnGriz]

Late to the thread, but for the record: Big house with too much heat loss for a Kuuma to heat completely in this climate during a real cold snap. However, 99% of the time I'm running on low, and I'm stretching out the reloads on the above freezing days, with a caveat. I found that the range setting on my Kuuma, as delivered, was too low to use the minimum knob setting without a fluffy creosote problem. I've been experimenting, and I think that about 1/2 turn up on the range screw is about right to use the lowest knob setting without causing problems. That's about a 10 -12 hour burn on a (jammed) full load of lodgepole pine. Plus, having the range screw turned up from stock, gives it some more output ability when it gets cold. So, my low, might be higher than your low, if you haven't changed the range.

Turning the knob to 11, gives me about a 5-6 hour burn, and yeah, if the days are say -15f, and the nights are -25f, or colder, I'm running at full speed in the day, but not too much off low at night so I can get a decent time to sleep. I haven't had a real cold snap where it got a lot colder than that for at least a few days, since I've had it, but I can tell the Kuuma won't do it alone when it comes. To be fair, I also haven't had cold enough weather to try max, max, on the controls, but with my soft wood, I don't think I'd get an overnight burn with the range at max, and I don't think that the range resistor is robust enough to adjust on a regular basis.

Coming to the original question - I think the thermostat is pretty much useless for my house. I have it hooked up, but really shouldn't. I would be better off putting a selector switch on the furnace (easier than remembering to twist the thermostat dial up and down on the floor above). If I'm running at 75% or more - high. Otherwise, low. High fan, with lower heat outputs just causes more fan cycling. And, again I could be wrong, but I think somebody with lower peak heat needs might be frustrated if they put a lot of work into installing the thermostat. Try it on low only (no thermostat), before you do, would be my advice.

Funny, a year or so ago, I posted that I thought the thermostat wasn't useful, and the responses I got back mostly said it was - so I thought it was just me....

What I was working on, but haven't finished, is getting the fan control switch to control the fan speeds. Hot plenum temps from high settings, while it still has wood, is high fan. Everything else, it automatically drops down to low. For me, that would be ideal. But, still not as cool as the variable speed setups some have installed.

I definitely agree that keeping the wood 1-2 inches away from the front face, regardless of wood length, gets the stove running clean and efficiently more quickly. It needs that blast furnace effect on the front of the pile in the beginning. I always did that, but still had more creosote than I was comfortable with in the first year. This year seems better (higher draft, and higher minimum setting), but I won't know for sure until May or June when I get back to the top of the chimney.

Since it was a very balmy almost 50 here today, I'm off at 10pm to do a near-cold start (groan), since the last time I loaded it was 24 hours ago. False spring is due to be over tomorrow though, so I'll be back to snow, and regular feeding.