Safety Precautions

For those of you who don't know, this is my first year burning coal and I have a hand fired hot blast furnace. So far I'm loving it. Estimated that I have already saved about $150 in oil and its only been a month. Anywho, I have a concern regarding power outages. I understand that generators and power inverters can be used and work great....if someone is home. However, what safety precautions, if any, do you guys have if they power goes out and nobody is home to hook one of these up to keep the blowers running. My fear this that without the blowers transferring heat away from the furnace that it will overheat quickly. For instance the other day, it got down to 10 deg at night and I had the fire blazing. The over the load door temp got up to 450-500 deg with the damper only open 1.5 turns and the baro starting to open at 0.025". Is this too hot for this type of stove? Burning at this temp it kept the house at a nice 73 all night long. I'm curious and fearful as to how fast that would rise if the blowers went out for more than a couple minutes. How much heat can a hand fired furnace handle since they are not made out of cast iron? How quickly would a mild (250 deg) fire climb if the blowers were not on for an extended period of time? If I knew I was going to be out for a while I might turn the damper down a little depending on the temp of the stove and the temp outside, but I'm still nervous about what might happen otherwise.

I agree with your concern and I don't really know of a fail safe way to keep the blowers running in a power outage OR what would happen if the blowers weren't operational at those temperatures. Best case scenario would be to have a battery backup up, or a generator that could automatically engage if there is a power failure.

My only defense is to #1 pull the filter and slow down heat output.
#2 get my generator online as quickly as possible..

Muddyjeep:

I burned wood in a Hot Blast 1557 like your for years. If I remember correctly the instructions recommend not filling with coal or wood above the fire brick, without the blowers operating.

You are right, that stove can get blazing hot when running wide open. I would burn red elm in mine loaded as full as I could stack it ---nothing but blue flame for hours, toasty warm indeed. Had two light switches upstairs one to each blower, often ran with just one blower, with no ill effect to the stove.

Just my 2 cents ..
Regards: john

When I purchased my house last year, it already came supplied with a 1537. It had been overheated, paint burned off of it, burned out grate, warped firebox, and only had one blower motor on it. I'm guessing the previous owner has had it much hotter than I ever have! And I've seen the stovepipe glow cherry red, and the steel around the door start to glow. Yes I got nervous, but never really hurt anything.
I comfortably limped the stove through last winter with one blower motor. I've also dealt with a couple power outages before, and like already mentioned, as long as you aren't overfilling the stove with coal, I really wouldn't worry too much about things. If you are home, close the primary air down a little, remove the air filter from the filter box, and don't expect to heat the house with it.
As I'm away, I don't really stress too much about a power outage and melting my stove down. I've seen mine ridiculously stupidly hot, and no harm done, thankfully. I do not recommend such practices. Haha Although, I do wonder how hot the previous owner had her!!! And I do see a small generator purchase in the near future....

Wheelo

Lightning wrote:Best case scenario would be to have a battery backup up

I agree with this lightning, however the cost is what draws me away from one of these. In order to get one that can run the blowers for more than 15 min they are a couple hundred bucks. And when you have a fire blazing at 400+ deg 15 min won't do much if your out for a couple hrs.

Buck47 wrote:If I remember correctly the instructions recommend not filling with coal or wood above the fire brick, without the blowers operating.

You are correct. I never fill above the top of the fire brick.

Wheelo wrote:I've seen the stovepipe glow cherry red, and the steel around the door start to glow. Yes I got nervous, but never really hurt anything

Wow. I would get nervous too if I saw the door glowing lol.

One thing I have noticed is that even when the stove is running at 450+ deg, my flue pipe never read more than about 175. The duct work gets so hot you can't keep your hand on it for more than a couple seconds. I haven't got a thermometer for the ducts yet, but plan on getting one soon to monitor its temp. There is one device I have seen that interests me some and its called the Quirky Wink Spotter. I saw it at home depot and it is only $40. Its a wifi device that can detect temp changes, senses light and also noises. I'm not sure how high of a temperature this thing can handle, I'm guessing not much and not enough to mount on or near the stove. However I think it could come in handy by utilizing the light sensor. This way if I'm away from the house and it detects the light goes off near it, it will send an alert to my phone to tell me the power is out. I would still need a battery backup for the wireless router, but a cheap one would work long enough to allow the device to send me the alert. This won't function the blowers or do anything for the stove temp, but at least it will let me know I need to get home and start shutting down the stove. So $40 for the sensor and another $40 for a cheap battery backup brings the total to about $80. Fairly cheap insurance to alert you that your stove could possibly overheat.

Installing a bi-metal thermostat on the stove to control intake air would guard against over heating of the stove.

I have thought about this, as well, with my new DS kozy king furnace..... Of course, the draft inducer motor will shut off, and the draft will return to idle, but I am concerned about how hot the ductwork will get if I'm not home to remove the air filter to permit un-restricted airflow through the system.

I have fiberglass insulated ductwork and Im not sure how much heat it can withstand.

You can make a back up power supply for much less than buying a UPS. Get a deep cycle big boat battery and buy an inverter ONLY big enough to do the two fans. ( so you don't waste energy).( $130 bucks?) You just plug it in when needed and put a tender on that battery every couple weeks. Used this set up many years on a whole house wood stove. You can also just get an inverter and hook it to your car thats running and use an extension cord to your blowers if you don't think power will be out for that long. Also can switch to brushless DC motors and skip the inverter and get a lot more run time. The deep cycle battery group 24 ( 600-800 cca) should run those fans for a couple hours anyways.

LDPosse wrote:I have fiberglass insulated ductwork and Im not sure how much heat it can withstand.

Don't quote me on this, but I think it can withstand quite a bit of heat. Typical household fiberglass insulation can handle temps of around 2000 deg F if I'm not mistaken. Should double check that though.

Formulabruce wrote:You can make a back up power supply for much less than buying a UPS. Get a deep cycle big boat battery and buy an inverter ONLY big enough to do the two fans. ( so you don't waste energy).( $130 bucks?) You just plug it in when needed and put a tender on that battery every couple weeks.

I thought about this and glad to know someone else has tried it and has had success with it. Although it still doesn't help if nobody is home at the time which is my primary concern. I'm thinking an inverter or a small generator is in my near future....maybe Santa will bring me one lol.

Muddy Jeep wrote:

I thought about this and glad to know someone else has tried it and has had success with it. Although it still doesn't help if nobody is home at the time which is my primary concern. I'm thinking an inverter or a small generator is in my near future....maybe Santa will bring me one lol.

You can run the battery/inverter system all the time with a tender or a 2 amp very small charger on the battery. When the power goes off, the tender isnt working but your deep cycle battery has a good long reserve. This is how a UPS basically works, BUt they used expensive gell cell batteries and fancy meter on the front. An auto switch over generator is big $$, all you need is a Tiny Honda "quiet" generator for this mission.. Good luck!! Keep warm

Formulabruce wrote:You can run the battery/inverter system all the time with a tender or a 2 amp very small charger on the battery. When the power goes off, the tender isnt working but your deep cycle battery has a good long reserve.

Ah, ok I see. I already have a small trickle charger. It might only be a 1.5 amp charger. Either way, I may have to give this a shot. Thanks for the idea!

Formulabruce wrote:You can make a back up power supply for much less than buying a UPS. Get a deep cycle big boat battery and buy an inverter ONLY big enough to do the two fans. ( so you don't waste energy).( $130 bucks?) You just plug it in when needed and put a tender on that battery every couple weeks. Used this set up many years on a whole house wood stove. You can also just get an inverter and hook it to your car thats running and use an extension cord to your blowers if you don't think power will be out for that long. Also can switch to brushless DC motors and skip the inverter and get a lot more run time. The deep cycle battery group 24 ( 600-800 cca) should run those fans for a couple hours anyways.

Some Anabaptist friends call Deep-Cycle batteries "Amish Lightning"

Keeping an eye on weather forecasts and be willing to turn down the stove before you leave might be the smartest thing. Granted you can't predict a failed transformer or car accident but most are caused by downed wires from ice or wind.