Blower keeps running on the Wood/coal/oil newmac 86g furnce help soon

[gweedow]

Hello all.
New here to the forum. 30 years ago I changed from coal to oil furnace. Now just today (11/30/12) They installed a Newmac 86g oil/wood coal system. I have a I think maybe a dumb question. Sorry but here gos. I made a nice fire out of wood, not coal yet. The thing is, the fire is ok but the cold air blower fan keeps running won't shut off. Two thermostats on wall. I have the oil one set a 69 degrees. The wood coal thermostat is set at 70 degrees. The Wood coal thermostat shows the room temp getting upto 78 degrees and the fan won't shut off. so I keep going down to the basemement and shutting the whole furnace off to shut the fan off. There is no fan switch on any of the two thermostats. Just a system slide switch that has heat and off. I slid that off but the fan blower still kept running. Like I said above, I had to go down and turn the whole system switch off to shut the blower down. Now I guess I let it just run off the oil part of the furnace. Untill I can get a guy to check it. Late now and Sat. tomorrow. They have emergency people. Maybe will call soon. hope oil part will work o.k. I have to keep an eye on it to make sure fan works in oil mode. Just hopeing one of you guys can answer now. Thanks PS. in Western Pennsylvania.

 

[cantoo]

I have a Hotblast so it's different but my blowers runs until the stove cools down to below the sensor set temperature. It has nothing to do with the room temperature as I have no thermostats hooked up. I'm not sure how the Newmac works but maybe the wood burning part is the same way, only way to slow a woodfire down is to cut down the air?

 

[cantoo]

I just took a look at some of the newmac specs and it looks like it does have a forced draft ss all you have to do to slow it down is shut off the draft, of course the blowers won't shut down until the furnace cools down from the reduced fire, this could take some time. I know my hotblast blower seem to run a real long time but as long as the sensor temp is higher than the trip point it will stay running. I have temp gauges on my ducting and even when the outside of the furnace feels cold the air temp is still well over 20 Celcius in the ducting.

 

[gweedow]

I have a Hotblast so it's different but my blowers runs until the stove cools down to below the sensor set temperature. It has nothing to do with the room temperature as I have no thermostats hooked up. I'm not sure how the Newmac works but maybe the wood burning part is the same way, only way to slow a woodfire down is to cut down the air?

Hmmmm. Maybe my newmac is the same way. Because about an half hour ago.The fan blower did stop when I let the wood fire almost go out. But still seems odd. I mean the fan kept running all that time and getting way over the set room temp. If I would of had a big humped up coal fire going no doors or draft open just a good in control fire, would that fan run all night and hours on end? Like I said I havn't had a coal furnace for all most 25 years and that was the old big ones. Any others out there. Did my installer miss some thing? Allso I may be to frugal, but a fan running a long time like that is going to up my electric bill. ha.

 

[laynes69]

There's 2 types of blowers, a forced draft and a distribution blower. I would assume it's the distribution blower your talking about. As long as there's fuel in the furnace, the blower will run or cycle off and on. With a woodfurnace, you can control the amount of heat needed by the fuel load. If little heat is needed, you build a small hot fire and if a high demand is needed then a larger load. It sounds like its a possibility your furnace may be too large for the home. Just watch loading it full and letting it idle, smaller more frequent loads will help reduce creosote. Usually when dealing with multi fuel furnace you want your wood thermostat 3 to 5 degrees ahead of the oil. A woodfurnace will not operate like a central furnace, that is on and off based on heating demand.

 

[reaperman]

I think everyone is in agreement here. First off you cannot control a wood burning furnace/stove with a thermostat. No matter what the owners manual or a salesman may tell you. Like any wood fired device, you take all of the heat it is willing to put out. The plenum fan serves two purposes. First, when the furnace reaches the temperature that is set with the limit switch, normally around 150 degrees. The plenum fan kicks in and distributes the warm air throughout the home. The second purpose of the plenum fan is to keep the wood furnace from getting too hot and overheating. As long as your fire is hot, the fan will continue to run, for hours if necessary to keep the furnace from overheating. Regardless of what the thermostat says. What you are doing by shutting off your whole system may lead to your furnace to overheating, which you dont want. Its much like a radiator fan keeping your radiator from letting your car overheat. I'd let the fan plenum keep running like its suppose to and open a window if the house gets too hot.

If the draft blower fan on the front of the wood furnace is the one that is running all of the time feeding the fire. And doesnt have a manual switch on it to turn it on or off. You can use whichever thermostat controls it and set the thermostat way up. As high as it will go, so the only way that fan would automatically turn on is if the house got that hot, which wont happen. Thats how my draft blower fan on my wood furnace operates also. So I have that thermostat set as high as it will go because I dont want it to turn on. This allows me to use the manual switch to turn the draft blower on and off. The way the system is designed and wired is why I have to have the thermostat turned up, it must open a circuit somewhere which give power to the manual switch. But with all of that said, I dont use the draft blower fan to start a fire or keep it going. My furnace has a spin damper and a slider door on the draft fan that allow enough air to operate the furnace without the fan. Best of luck and welcome to a warm home with your new furnace

 

[gweedow]

I think everyone is in agreement here. First off you cannot control a wood burning furnace/stove with a thermostat. No matter what the owners manual or a salesman may tell you. Like any wood fired device, you take all of the heat it is willing to put out. The plenum fan serves two purposes. First, when the furnace reaches the temperature that is set with the limit switch, normally around 150 degrees. The plenum fan kicks in and distributes the warm air throughout the home. The second purpose of the plenum fan is to keep the wood furnace from getting too hot and overheating. As long as your fire is hot, the fan will continue to run, for hours if necessary to keep the furnace from overheating. Regardless of what the thermostat says. What you are doing by shutting off your whole system may lead to your furnace to overheating, which you dont want. Its much like a radiator fan keeping your radiator from letting your car overheat. I'd let the fan plenum keep running like its suppose to and open a window if the house gets too hot.

If the draft blower fan on the front of the wood furnace is the one that is running all of the time feeding the fire. And doesnt have a manual switch on it to turn it on or off. You can use whichever thermostat controls it and set the thermostat way up. As high as it will go, so the only way that fan would automatically turn on is if the house got that hot, which wont happen. Thats how my draft blower fan on my wood furnace operates also. So I have that thermostat set as high as it will go because I dont want it to turn on. This allows me to use the manual switch to turn the draft blower on and off. The way the system is designed and wired is why I have to have the thermostat turned up, it must open a circuit somewhere which give power to the manual switch. But with all of that said, I dont use the draft blower fan to start a fire or keep it going. My furnace has a spin damper and a slider door on the draft fan that allow enough air to operate the furnace without the fan. Best of luck and welcome to a warm home with your new furnace

Thank you very very much for the kind welcome and luck, thank you all. I fill much better. I do like the furnace. Very nice and warm. Trying to cut down on that liquid gold,oil.