I just wanted to give my experience with my new Clayton CF700M since I didn't find a ton of info on the net prior to purchase in hopes this helps someone else out. I know these furnaces are discontinued and are probalby not as many around as with some other brands and models.
As far as reference, I grew up in southern Ohio and we heated primarily with the local hard woods and Riteway stoves and the like. Many years later I now live in NW Montana and the wood of course is quite a bit different.
My house is a '79, three level, 3400 sqft home, with 2x6 on 2' centers. Not super efficient but pretty good over all. The house originally had a wood furnace and base board electric but a previous owner removed the furnace and installed a ground source heat pump. Upon purchasing the home I slowly started removing the baseboard heaters in the upper two levels and since I already had a concrete block chimney not being used, I bought a cheap, used, Suburban wood stove off Craigslist as a small backup heat source in case of power outages. I found myself firing the Suburban up when really cold temps made the geothermal want to jump into auxiliary mode to save electric.
Jump to 17 years later and my thirty year old geothermal system needs a $3500.00 part which is a whole other story. So as a quick fix, looking at single digit temps coming in a few weeks, I went on the hunt for a wood furnace to get us by. Started looking for used without much luck. Not much new out there either due to EPA in the end months of 2020 and the few nice ones I found, sadly, were out of my price range.
So in my low budget search for used furnaces and stoves I stumbled upon a refurbished CF700M, which I believe was also marketed as an Ashley AF700, built by US Stoves but has been discontinued like many wood furnaces in the recent years. After doing what reading I could, I found that they were sold at Tractor Supply retailers and the like, so this led me to believe that this was and entry level furnace. The furnace that I purchased was off Ebay! One left as I am writing this post.
(broken link removed to https://www.ebay.com/itm/US-Stove-Wood-Furnace-2750-sf-w-Dual-550-CFM-Blowers-CF700M-Clayton-Refurbished/153852542362?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649)
I purchase it for $1350 and free shipping so I was not real worried if it failed to work well in my situation. I received it in roughly two weeks (which if pretty good shipping time in Montana) with only some minor wrinkling/bending of outer rear shell around blowing mounting area and upon removing most of the fire brick found the fire blanket slightly torn and bunched up at one side. A heads up here there is conflicting info from the manufacturer in the literature as to weather or not burn fires in it outside to burn off fumes. I attempted to do this twice with little effect partially due to no chimney/draft hooked up. I then got it in the house, assembled it, hooked it up to the chimney, and plugged it in. As I am writing this it is still not plumbed into the duct work.
First impressions were that it really didn't feel quite 550 lbs. the shipper told me it was. The blowers are made in China but seem to be fine with quiet, super smooth bearings that spin for quite a while once shut off. The fire brick, which I removed all but back wall and ceiling to help loose some weight for moving, was typical. So other than maybe being built beefier and having a larger fire box, I thought it may work.
I fired it up and in the process of figuring out my new purchase almost fumigated us all. Fumes were extreme. Upper floors were hazy looking accross the rooms. Headaches and sore throats all around and of course a lot of open doors and windows. I assume this is something all new wood burners need to be aware of, I was just not ready for the extremity especially after running a couple of burns in outside.
Once seasoned so we could stay in the house I found that I had purchased a stove that did not have any way of automatically adjusting the air intake like my prior stoves did with either a bi-metallic controlled door or blower fan. Also found I had to get this furnace super hot in order to get the blowers for the duct work to even kick on. I'm sure all of this has to do with attempting to meet EPA requirements.
I started brain storming and pulled the thermo snap switch and researched it, finding that it was set for 302 degrees! I went in town and purchased a 110 degree switch. I was recommended not to go lower in case summer temps were hot enough to make the blowers come on without the furnace being fired up. Not and issue in my cool lower level in NW Montana but something to keep in mind for those who may have a warmer environment. So now I have the blowers coming on at a more reasonable temp but I wanted to be able to shut off the blowers if I reached the called for temp in our main living area. Originally I was trying to fiqure out how to hook a typical furnace thermostate into the mix as a cut off but things get complicated switching voltages. Then with help from a electrical specialty store (Platt Electric) I figured out a good old fashioned baseboard heater thermostate would do the trick nicely and oddly enough I had a few! So now I have blowers coming on around 110 degrees and off at whatever temp I have the baseboard heater set at which will probably be the 72-73 mark.
Next I wanted to have more control over the chimney draft. Originally there was a biometric pressure damper in the chimney which I verified is still ok to do with Montana code but I decided to put a manual damper in for more control of my two plus story chimney which is located right at the base of the Rocky Mountains which can create some odd drafts believe it or not. While I had the chimney back apart I also add some cement blocks under the unit to make a little higher for slightly easier tending.
On to the next issue. Incoming air.... This unit has a manual draft door that is opened and closed by a crude turn handle. Below this adjustable door is three air openings. This door also has a small metered hole in it that is over the center opening so if the door is complete close air still enters here. Doing some research some people are putting magnets over this hole to cut of this air supply as another way to have further air control. This stove also has no grate. You build your fire directly on bricks, building your fire upside down from what I'm used to when starting one. This fire box also has a metered hole centered below the glass fire box door to, I believe, aid in keeping the glass door clean and help the burn. Then down lower yet on the unit there are two more openings of around and inch square that I believe sends air to the three air tubes on the ceiling of the burn box. These tubes look like propane grill burner tubes. So with the damper shut all the way there are four openings taking in air all the time. This being said when the damper is in the closed possition it certainly cuts back the air noticeably to the fire. I have started playing with the chimney damper and a magnet covering the damper door hole on warm days to cut things back. Above the burn box is a cavity housing three sections of large cast pipe that the smoke and heat are winding it's way through to reach the chimney. I still have not been able to figure out where the smoke actually exits the burn box to enter this area or the exact route it travels in this upper chamber.
So as to how it's working so far... It's been two weeks running, not hooked up to the duct system, burning a mix of dry, larch, birch, fir, and such. We've seen 7 degrees here at night and I'm still able to keep the central part of the middle floor in the 73 degree range. Now this it's a given, my lower level is much warmer because it's coming through a downstairs doorway and up the main hall steps and the outer middle floor bedrooms are cooler especially if doors are closed for sleeping. In warmer temps, 25-40 degrees, I'm getting up to twelve hours burn time to coals so my concern of the fire box being too small seems to be negated. Getting down to single digits it's closer to eight hour burn times. For a furnace rated for 2750 sqft, not hooked up to duct work yet, in a 3400 sqft home, I couldn't be happier!
I now have a bi-metallic thermo control assembly on order from Hitzer I plan on attempting to install to the incoming air damper door for a little further automatic control, as well as a chimney thermometer, and Koal saver shovel. I also already have the optional air return box that excepts an air filter and also aids in the hook up to my retune air trunk portion of the house duct work.
Needless to say, I'm anxous to see how much better she'll do once fully plumed in. Hope this helps anyone considering one of these units.
![[Hearth.com] Clayton CF700M](https://www.hearth.com/talk/attachments/20201016_094513-webp.265658/ "[Hearth.com] Clayton CF700M")
![[Hearth.com] Clayton CF700M](https://www.hearth.com/talk/attachments/20201016_094529-webp.265659/ "[Hearth.com] Clayton CF700M")
![[Hearth.com] Clayton CF700M](https://www.hearth.com/talk/attachments/20201013_141459-webp.265660/ "[Hearth.com] Clayton CF700M")
![[Hearth.com] Clayton CF700M](https://www.hearth.com/talk/attachments/20201014_102854-webp.265661/ "[Hearth.com] Clayton CF700M")
As far as reference, I grew up in southern Ohio and we heated primarily with the local hard woods and Riteway stoves and the like. Many years later I now live in NW Montana and the wood of course is quite a bit different.
My house is a '79, three level, 3400 sqft home, with 2x6 on 2' centers. Not super efficient but pretty good over all. The house originally had a wood furnace and base board electric but a previous owner removed the furnace and installed a ground source heat pump. Upon purchasing the home I slowly started removing the baseboard heaters in the upper two levels and since I already had a concrete block chimney not being used, I bought a cheap, used, Suburban wood stove off Craigslist as a small backup heat source in case of power outages. I found myself firing the Suburban up when really cold temps made the geothermal want to jump into auxiliary mode to save electric.
Jump to 17 years later and my thirty year old geothermal system needs a $3500.00 part which is a whole other story. So as a quick fix, looking at single digit temps coming in a few weeks, I went on the hunt for a wood furnace to get us by. Started looking for used without much luck. Not much new out there either due to EPA in the end months of 2020 and the few nice ones I found, sadly, were out of my price range.
So in my low budget search for used furnaces and stoves I stumbled upon a refurbished CF700M, which I believe was also marketed as an Ashley AF700, built by US Stoves but has been discontinued like many wood furnaces in the recent years. After doing what reading I could, I found that they were sold at Tractor Supply retailers and the like, so this led me to believe that this was and entry level furnace. The furnace that I purchased was off Ebay! One left as I am writing this post.
(broken link removed to https://www.ebay.com/itm/US-Stove-Wood-Furnace-2750-sf-w-Dual-550-CFM-Blowers-CF700M-Clayton-Refurbished/153852542362?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649)
I purchase it for $1350 and free shipping so I was not real worried if it failed to work well in my situation. I received it in roughly two weeks (which if pretty good shipping time in Montana) with only some minor wrinkling/bending of outer rear shell around blowing mounting area and upon removing most of the fire brick found the fire blanket slightly torn and bunched up at one side. A heads up here there is conflicting info from the manufacturer in the literature as to weather or not burn fires in it outside to burn off fumes. I attempted to do this twice with little effect partially due to no chimney/draft hooked up. I then got it in the house, assembled it, hooked it up to the chimney, and plugged it in. As I am writing this it is still not plumbed into the duct work.
First impressions were that it really didn't feel quite 550 lbs. the shipper told me it was. The blowers are made in China but seem to be fine with quiet, super smooth bearings that spin for quite a while once shut off. The fire brick, which I removed all but back wall and ceiling to help loose some weight for moving, was typical. So other than maybe being built beefier and having a larger fire box, I thought it may work.
I fired it up and in the process of figuring out my new purchase almost fumigated us all. Fumes were extreme. Upper floors were hazy looking accross the rooms. Headaches and sore throats all around and of course a lot of open doors and windows. I assume this is something all new wood burners need to be aware of, I was just not ready for the extremity especially after running a couple of burns in outside.
Once seasoned so we could stay in the house I found that I had purchased a stove that did not have any way of automatically adjusting the air intake like my prior stoves did with either a bi-metallic controlled door or blower fan. Also found I had to get this furnace super hot in order to get the blowers for the duct work to even kick on. I'm sure all of this has to do with attempting to meet EPA requirements.
I started brain storming and pulled the thermo snap switch and researched it, finding that it was set for 302 degrees! I went in town and purchased a 110 degree switch. I was recommended not to go lower in case summer temps were hot enough to make the blowers come on without the furnace being fired up. Not and issue in my cool lower level in NW Montana but something to keep in mind for those who may have a warmer environment. So now I have the blowers coming on at a more reasonable temp but I wanted to be able to shut off the blowers if I reached the called for temp in our main living area. Originally I was trying to fiqure out how to hook a typical furnace thermostate into the mix as a cut off but things get complicated switching voltages. Then with help from a electrical specialty store (Platt Electric) I figured out a good old fashioned baseboard heater thermostate would do the trick nicely and oddly enough I had a few! So now I have blowers coming on around 110 degrees and off at whatever temp I have the baseboard heater set at which will probably be the 72-73 mark.
Next I wanted to have more control over the chimney draft. Originally there was a biometric pressure damper in the chimney which I verified is still ok to do with Montana code but I decided to put a manual damper in for more control of my two plus story chimney which is located right at the base of the Rocky Mountains which can create some odd drafts believe it or not. While I had the chimney back apart I also add some cement blocks under the unit to make a little higher for slightly easier tending.
On to the next issue. Incoming air.... This unit has a manual draft door that is opened and closed by a crude turn handle. Below this adjustable door is three air openings. This door also has a small metered hole in it that is over the center opening so if the door is complete close air still enters here. Doing some research some people are putting magnets over this hole to cut of this air supply as another way to have further air control. This stove also has no grate. You build your fire directly on bricks, building your fire upside down from what I'm used to when starting one. This fire box also has a metered hole centered below the glass fire box door to, I believe, aid in keeping the glass door clean and help the burn. Then down lower yet on the unit there are two more openings of around and inch square that I believe sends air to the three air tubes on the ceiling of the burn box. These tubes look like propane grill burner tubes. So with the damper shut all the way there are four openings taking in air all the time. This being said when the damper is in the closed possition it certainly cuts back the air noticeably to the fire. I have started playing with the chimney damper and a magnet covering the damper door hole on warm days to cut things back. Above the burn box is a cavity housing three sections of large cast pipe that the smoke and heat are winding it's way through to reach the chimney. I still have not been able to figure out where the smoke actually exits the burn box to enter this area or the exact route it travels in this upper chamber.
So as to how it's working so far... It's been two weeks running, not hooked up to the duct system, burning a mix of dry, larch, birch, fir, and such. We've seen 7 degrees here at night and I'm still able to keep the central part of the middle floor in the 73 degree range. Now this it's a given, my lower level is much warmer because it's coming through a downstairs doorway and up the main hall steps and the outer middle floor bedrooms are cooler especially if doors are closed for sleeping. In warmer temps, 25-40 degrees, I'm getting up to twelve hours burn time to coals so my concern of the fire box being too small seems to be negated. Getting down to single digits it's closer to eight hour burn times. For a furnace rated for 2750 sqft, not hooked up to duct work yet, in a 3400 sqft home, I couldn't be happier!
I now have a bi-metallic thermo control assembly on order from Hitzer I plan on attempting to install to the incoming air damper door for a little further automatic control, as well as a chimney thermometer, and Koal saver shovel. I also already have the optional air return box that excepts an air filter and also aids in the hook up to my retune air trunk portion of the house duct work.
Needless to say, I'm anxous to see how much better she'll do once fully plumed in. Hope this helps anyone considering one of these units.
