Questions on running a Newmac Multifuel Hot Air Furnace (Coal), Coal Brands, Ect...

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DavidB.

New Member
Jan 24, 2011
6
Northern Maine
This is my first time posting on this website and I wanted to take an opportunity to thank everyone in advance for the onslaught of information that I know will be forthcoming. I've got a Newmac multifuel furnace. I can burn wood/oil/coal. The model number is a CL86-96G; it's a hot air furnace. I just had a house built the other year so it's very new, an 1800 square foot ranch. It's a Maple Leaf modular home with R-50 in the roof and R-25 in the walls. I'm in Northern Maine so it does get cold up here. Today is 20 below.
I tried burning coal last year and had one heck of a time trying to get it going and almost gave up. Come to find out, I was using the wrong kind of coal for my furnace. I was using stove coal when I finally figured out that the stove standard was nut coal. I've finally been able to get the nut coal burning for the last couple of weeks fairly well to the point where I've been running the furnace on coal around the clock without having to relight it with wood. I got a couple of tons of Reading, which as I've seen on many forums can be problematic and really has been. I can probably get close to 12hrs on a full load which is about a bag and a half to 2 bags which would be 75-100lbs. Although, I don't think that the bitter cold is helping. Right now I've got about a little less than a ton of Reading Nut coal and and less than a ton of Reading Stove coal. I'm actually able to get the stove coal to light when I've got a nice bed of the nut coal burning. I'm able to mix it a little. Within the next week or so, I'll be getting a ton of Blashack Nut Coal which I'm anxious to try as I've heard that it burns much better and has a higher btu output. I've got a local store that also sells it, but it's expensive and I'm thinking that I may go and purchase a couple 40lb bags today just to give it a try and get a feel for it.

I've got a couple of questions concerning draft control which I've got very little understanding of. I've got a barometric damper set at .5 right now which is what the furnace manual requires. This seems to be working fine and seems to be an industry standard.
A couple of issues that I'm trying to work out is longevity of the burn, and trying to get the house to warm up faster when the coal fire burns down.

Temperature: One of the big issues is if I bank the coal or even just fill the box up to the level or lip as the manual indicates at night, let's say around 10pm, by 6am or 7am the temperature of the house has gone from between 71-73 to anywhere from 61-64. I still have a decent bed of coals, but a bit less than what I obviously had the night before once I've shaken out the ash and poked some holes from the bottom of the bed via the ashpan area. I've also cleaned out the ashpan as well. This process I will do at night and in the morning. If I'm home throughout the day, I may go and shake the grates a little every few hours (3-5hrs), in order to maintain the red glow and a sufficient amount of airflow to the coals.

If the temperature is down to 61-64, then after preparing and loading the furnace, I'll leave the ash pan door wide open for however long it takes to bring the temperature up to and above 70. This can take a few hours 3-5hrs. I've got the top draft control
that has the round knob set in the middle which says minimum. Normally, when I've got the temp that I want in the house, I just leave the upper draft knob control to minimum and the bottom ashpan little single lever draft switch to wide open with the ash pan door closed. This can keep the temperature constant for some time. I can provide pictures of this if needed.

I've got the fan set at 69 which blows air on the top of the fire, but shuts off when the temp hits 70. I've got two digital controls upstairs and only one zone for the house. I've got one control for the oil, and one for the wood/coal. I've tried playing with the draft control a bit, but feel that if I over clock it and maximize the upper draft control knob, I'll be losing a lot of heat out the double insulated metal chimney. I pretty much leave the top round draft knob at minimum all the time which sets in the center of the draft range. If I were to move it far to the left, it would be closed which is where it's supposed to be If I'm burning oil along with the ashpan draft lever being at the closed position as well.

If anyone has any tips or needs more infomation, please let me know and I'll be happy to provide them.

Thanks again, David B.
 
Hold your tongue homey : ) This forum has help hundreds maybe thousands with knowledge given freely. Saving us the masses unknown amount of $$. If you don't get a response it simply means no one has an answer at the moment. Give it time I am sure someone will help you out.
 
Also, hot air furnaces are a minority in this forum. You may want to do some searches. Find out who the other hot air furnace users are and send them a PM. That crowd may not log onto this web site as often as the boiler crowd...
 
You posted in The Boiler Room - Wood Boilers and Furnaces

Your question seems to be all about coal.
 
If burning anthracite, you want no air above the fire. If your running .05 on the baro then something isn't right with the draft settings. In order for coal burn properly, you need a good deep bed. I would give the fire more air underneath and eliminate any air above. Look on YouTube and view some of the videos on coal burning. They should be very helpful. I would think a charge in excess of 50 pounds shouldn't have a problem keeping the house warm. Hope this helps.
 
Thank you all for your efforts. What I'm trying to find is someone that actually has the same model that I do since having contacted the company numerous times within the last month and half has yeilded very dismal results. They referred me to a guy by the name of Jeff out of Heating World in Pennsylvania assuring me that if he couldn't help me, then to call them back and they would give me a hand. The proverbial passing of the buck. I've tried to get a hold of Jeff after talking with him a few times and now when I call, he doesn't return my phone calls. All I had asked of him, as well as the Newmac representative in Nova Scotia was if they could put me in touch with a customer that they'd sold the same multifuel model to that was actually utilizing the coal portion of it with success. After scouring their database, the Newmac rep said that he can't find anyone but will try to keep looking, but that this was a busy time of year for them. He was giving me the brush off and I let him, in a nice professional manner know, that I was not comforted by his words and that it seemed that the effort he was going to expend on my behalf would be less than accomodating. It's pretty sad when you work for a company for many years, sell their products, and don't know how they work. I've even offered to call the customer that they find on my own dime. You can see how well they stand behind their product. Anyways, that's why I turned to this forum. Alright, let's get to the some of the responses.
Sparke, thank you for your words of hope and faith, I appreciate it. I have learned that when adding any amount of coal, as long as I crack the ash pan door located below, the coal will light very fast. I can even leave it open for a half hour to an hour and the temperature will go up considerably, which has kind of saved my but, the problem was it was taking an inordinate amount of time to do this. Meaning could be several hours. I just learned this past week by trying something different how to make it go up even faster. I moved the knob lever above the fan that I have just above the loading door to the left towards the closed positon. This really got the temp to go up much faster, within an hour by 6-7 degrees. I'm sure this will be dependent on the amount, or load of coal that I have in there will determine how quickly it goes up. It's pretty sad that the manual has only a couple of sentences on the draft control. I was getting desperate so I'm kind of reading and rereading everything and trying to think outside of the box at the same time.
In the manual, the illustraton of the draft control above the loading door lists that it needs to be in the closed postion when utilizing or heating with oil. Then in the middle is listed the words minimum, and then towards the end of the right side is maximum. The manual also states that the knob should be in the maximum position when utilizing wood or coal. After talking to some friends, they mentioned that if I kept it all the way to maximum that the initial intent would be to have it in this positon when starting a wood fire or coal fire. This is when the most draft would be desired. They then said that I should pare it back once the fire was going so as not to lose all of my heat out of the chimney. Well that got me thinking. I have actually been leaving it right in the middle at the minimum position the last month or so, so that even if I started a fire I would have it in the minimum position. Barring the lack of information on the draft in the manual I figured this past week, why not move the position of the draft knob to half way between the minimum position and the closed position where it should be when heating with oil; again this is to the left. In essence from a range of 1-100%, it would be at 25%. My initial concern which was keeping me from doing it before was that I didn't want to blow my furnace with the build up of gas. Well, I figured what the hell. I've tried a whole slew of other things and the draft was still open with the ash pan door open so the coal would be raging hot to burn the gases and the flue still open for them to escape. Man, what a difference that made.
Just doing that, has allowed me a huge advantage as far as getting the temperature to rise. Now I'm not mechanically inclined by nature, but I also figured, minimizing that draft allows the temperature in the box to get hotter faster, allowing the blower to kick in more often to get the heat out of the loading box and into the house. This move was a Godsent. Now I can get the temperature in the house to move up very fast in less than an hour. So this part of the equation is done. Now I have one more issue. This is the longevity of the fire, how to get it to last long.
Since this email is a little longwinded, I'll put it in the next one.
David B.
 
David, I think Layne is right on. Although I am far from a master I have burned some coal in my time in a Buderous wood boiler. I think one of the most important things is draft coming from under the fire. You said you have a draft control BUT is it possible that even with it wide open your chimney does not have adequate draft? I think the only way to answer that question is to borrow a manometer and check out your chimney draft. Hope I am understanding your issue correctly but getting the fire to respond quicker, I think is a funciton of draft. Thats why it helps to open lower door.
 
I sold newmac units for 12 years here in ny and the north east most units sold were wood oil
only sold about 10G units but sold 80 to 100 wood oil C units
did you get the cast iron plate that goes in the front of the unit that makes it have a deeper fire box
I ask this because I had found units that were sold with out them by other dealers
it has been 12years since I retired so I don't know how dealers are now
 
In response to Sparke, and Layne. I actually had to come and have my furnace tested last year after it was set up because the master plumbing and heating guy that I paid about $16,000.00 to do my plumbing and heating never set my barometric damper. When quesioned about it he said that they usually wait about 5 weeks letting the furnace work before they do this. This was obviously a copout and a load of crap after I checked with some other heating guys and said that this should never have been done. In looking at the furnace everything was setup right from what I can see. I did have someone come in afterwards and set the damper to .5 and tested it. Needless to say, the plumbing and heating master that I had do the work who supposedly had 30plus years of experiences had done a few other things that I wasn't too impressed with. Oh well.
I've noticed with the ash pan door lever which can move probably a total of an inch and a half to 2 inches left to right is supposed to control the air flow to the underneath of the bed of coals. I've played with this in multiple variations. If I bring it to the left, it's in the closed position, and to the right is open, similar to the loading door draft control. The fan above from what I was told that actually works off of my digital thermometer with the one zone that I have for my ranch house actually blows air across the top of the fire. Obviously, if I'm burning wood, it would help the wood by providing oxygen to the fire; however, with coal it would seem to me to have the opposite affect. I leave the digital temperature set at 69, so when it hits 70, the fan kicks off. I've also tried just turning it off and am wondering if anyone would agree if I should just leave it off when utilizing coal as I don't think that it's really doing anything for me in this respect.
One of the reps that I've been mainly talking to at Newmac tried to explain to me that the fan is supposed to take the hot air from the loading area and circulate it down through the door once it hits a certain temperature, since the door has a hollowed out square passage down and into the bottom of the ash pan where it would then come back up into the bed of coals from underneath. He tried explaining some type of theory to me about how this works, but I've got to tell you. Everytime I've tried this by leaving the fan on, I've not felt any air coming through the passageway. It's very wide open, the size of the door and there's nothing blocking it as I've checked. I'm wondering if it actually works the way they say it does, because, I'm not seeing it. Again, I could take pictures of this and download it or post it somehow on this website so people can see to give you guys a better idea.
Thanks again for all of your input so far. I really do appreciate it.

David B.
Now, my last issue is the longevity of the fire. I think I got it yesterday to burn over 12hrs and remain at around 74 degrees which to me is awsome. Now I've heard of some people getting their fire to last 16 to over 30hrs, not with a furnace, but more a boiler or stoker. I'm wondering if this is even possilbe with a furnace. My goal is that once I can get this running really well, then I'll be more than happy to help anyone out there with the same furnace by Newmac to get their's running in tip top shape, especially after all the trouble that I've had with mine along with the lack of support from the company.
 
For Porkie: I don't know about a cast iron plate, the loading door and ash pan door seem pretty solid, possibly made of cast iron, but the inside is pretty much the firebrick from what I can see. Later on today, I'll posting some pictures so everyone can see it. I'll try and see if I can get dimensions later on today when I try posting pictures.
David B.
 
Hey Dave, This place has everything you ever needed to know about burning coal. Not sure if you have visited their forums yet but there is a ton of knowledge there... http://nepacrossroads.com/
 
Your coal fire is based off of the need for heat. 12 hours doesnt sound bad. When you hear much longer burns, it's due to an extremely low rate of fire. In your case it wouldn't heat the house. I would turn down the house thermostat and try it. Even though I haven't seen or operated a unit like that, coal needs certain requirements to burn correctly. Get a manometer, and try a lower setting. Only you will know how to set it for what works. Every install is different. Sounds to me like things are getting better.
 
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I'm getting there, thanks for everything guys. Yew Sparke, I have visited nepacrossroads, and they had one thing on a newmac. I've got to tell you, there's really nothing out there for this system. My goal is that once I get this thing running well, I'll either be a spokesman for people not to buy newmac furnaces due to their lack of knowledge on how they run themselves along with crappy customer service, or I'll become a spokesman to help all the poor people that buy them and need help utilizing coal.

David B.
 
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