Confusion around stove temp and and blower control.

[stovetoohot]

Hello, and thanks for reading and your time to respond if you choose to.

I have an Englands Wood Stove (Model 13-NC) with a glass front. I am concerned because often after putting a large log in the stove, my thermostat often shoots up into the > 600-degree range, which I have been advised is an 'overburn' area and can cause a chimney fire. I have the chimney cleaned regularly, but still, it makes me nervous to put a log in and leave the house, or overnight.

The stove _does_ have a blower on it, that if I turn on, will cool the stove down to a better temperature range of, but it is a manual blower, meaning I would have to either always have the blower on while I am gone or all night long which isn't ideal.

So, I looked into installing a thermostat magnet switch for the blower that would turn the blower on when the stove got up to 55o degrees, lets say, but all the thermostat switches I can find will turn on at 110 degrees, and off at 90 degrees, which is so much lower than the temps I am dealing with, I am confused what I am missing.

Can anyone advise to me how to correctly rig up a temp sensor switch to my blower to have it come on at higher temperatures, or advise about some other solution that I have not considered?

Thanks again
J

 

[Ludlow]

Put a steel washer under the mounting screw. It will come on later and go off sooner in theory, or may not work at all. Worth a try.

 

[stovetoohot]

Put a steel washer under the mounting screw. It will come on later and go off sooner in theory, or may not work at all. Worth a try.

Thanks, but still confused why these products are designed for a temp so much lower than what my stove is running.

 

[bholler]

Hello, and thanks for reading and your time to respond if you choose to.

I have an Englands Wood Stove (Model 13-NC) with a glass front. I am concerned because often after putting a large log in the stove, my thermostat often shoots up into the > 600-degree range, which I have been advised is an 'overburn' area and can cause a chimney fire. I have the chimney cleaned regularly, but still, it makes me nervous to put a log in and leave the house, or overnight.

The stove _does_ have a blower on it, that if I turn on, will cool the stove down to a better temperature range of, but it is a manual blower, meaning I would have to either always have the blower on while I am gone or all night long which isn't ideal.

So, I looked into installing a thermostat magnet switch for the blower that would turn the blower on when the stove got up to 55o degrees, lets say, but all the thermostat switches I can find will turn on at 110 degrees, and off at 90 degrees, which is so much lower than the temps I am dealing with, I am confused what I am missing.

Can anyone advise to me how to correctly rig up a temp sensor switch to my blower to have it come on at higher temperatures, or advise about some other solution that I have not considered?

Thanks again
J

Where are you measuring that 600 degrees?

 

[Hogwildz]

600 degrees stove top is fine, normal temp.
As far as the fan, yes is auto turns on at 110, and turns off at 90 so it isn't blowing cold air out when it hits 90 or below. So if you typically run 500-600, the fan comes on at 100 and runs the entire time the stove temp is over 110. Once the fuel load burns down and the stove temp dips below 90, it shuts off.

 

[stovetoohot]

Where are you measuring that 600 degrees?

On the top of the stove.

 

[stovetoohot]

600 degrees stove top is fine, normal temp.
As far as the fan, yes is auto turns on at 110, and turns off at 90 so it isn't blowing cold air out when it hits 90 or below. So if you typically run 500-600, the fan comes on at 100 and runs the entire time the stove temp is over 110. Once the fuel load burns down and the stove temp dips below 90, it shuts off.

Thanks. But then, the blower is basically always on - which isn't what supposed to happen is it?

 

[Hogwildz]

Thanks. But then, the blower is basically always on - which isn't what supposed to happen is it?

Yes, that is exactly what is supposed to happen. Fan doesn't run till certain temp, so it ain't blowing cold air around. Then stove hits certain temp, fan comes on, circulates heated air during the time the stove it hot/warm, then shuts back off when temp drops, so not to blow cold air. Make sense?

 

[stovetoohot]

Yes, that is exactly what is supposed to happen. Fan doesn't run till certain temp, so it ain't blowing cold air around. Then stove hits certain temp, fan comes on, circulates heated air during the time the stove it hot/warm, then shuts back off when temp drops, so not to blow cold air. Make sense?

Makes sense, but the fan is so loud, and I only want it to come on when the stove has reached a level that is too hot, not all the time. In this case, I could just switch the fan on and off manually. But your response makes sense, I just wish ther was a way to have the fan come on when the stove was too hot.

 

[Hogwildz]

The fan is primarily for heated air circulation/distribution around the room/home. The cooling effect on the stove is a byproduct of circulating the heated air away from the stove. The temps you are worried about is not a temp to worry about. At 600 your just achieving cruising temp, if not a little higher.

 

[Hogwildz]

Is too hot to you the stove temps worrying you, or is the house too hot?

 

[stovetoohot]

Is too hot to you the stove temps worrying you, or is the house too hot?

The house is not too hot, I am just worried the stove temp is too hot and coul cause a chimney fire. (The thermostat says over 600 is 'overburn'.

 

[Hogwildz]

In that size of a place, you don't even need a fan. If you want cooler burn temps, which I don't know why you would. Put larger splits of wood in, or smaller total loads. If you are worried about 600 degrees, there is no need to be.

 

[bholler]

On the top of the stove.

In that case 600 is not to hot

 

[bholler]

The house is not too hot, I am just worried the stove temp is too hot and coul cause a chimney fire. (The thermostat says over 600 is 'overburn'.

That is because you are using a stove pipe thermometer on your stove top. The ranges are not right

 

[Hogwildz]

The house is not too hot, I am just worried the stove temp is too hot and coul cause a chimney fire. (The thermostat says over 600 is 'overburn'.

Ahhhhh ok. Let me offer you some soothing words to that worry.
I assume you are using a a magnetic stove pipe thermometer? You are using it on the stove top?
You can't have a chimney fire unless: 1. you are burning wet wood that is not ready to be burnt. Think anything over 20-25% moisture content. 2. Your draft sucks, and your smoldering the wood while it burns, or actually doesn't burn real great. 3. You don't regularly inspect and sweep your stack, even a few times a season till you get a feel for if your burning habits are good or not, will dictate whether a build up or not to catch fire.

Burn good dry wood. 600-650 with some peaks at 700 is not un-normal for that stove. If you are at 600 you are golden. You can't go by the magnetic thermo, just use that as a reference only.

You are achieving a temp, that you should be shooting for.

 

[stovetoohot]

Ahhhhh ok. Let me offer you some soothing words to that worry.
I assume you are using a a magnetic stove pipe thermometer? You are using it on the stove top?
You can't have a chimney fire unless: 1. you are burning wet wood that is not ready to be burnt. Think anything over 20-25% moisture content. 2. Your draft sucks, and your smoldering the wood while it burns, or actually doesn't burn real great. 3. You don't regularly inspect and sweep your stack, even a few times a season till you get a feel for if your burning habits are good or not, will dictate whether a build up or not to catch fire.

Get two 45s and a diagonal section of pipe where you the the 90's and horizontal run. Burn good dry wood. 600-650 with some peaks at 700 is not un-normal for that stove. If you are at 600 you are golden. You can't go by the magnetic thermo, just use that as a reference only.

You are achieving a temp, that you should be shooting for.

Awesome, thanks so much for all the advice and feedback. I really appreciate it! Do you recommend a do-it-yourself chimney sweet device?

 

[wooduser]

Your manual on operating the wood stove makes the following guidance, in part:

<<BUILDING A FIRE 1. Open the air inlet control fully (See Illustration 6). 2. Place a small amount of crumpled paper or approved starter material in the stove. 3. Cover the paper or approved starter material with a generous amount of kindling in a “teepee” shape, and a few small pieces of wood. 4. Ignite this fuel and close the door most of the way (leave it open slightly). 5. Add larger pieces of wood as the fire progresses, being careful not to overload. Do not fill the firebox beyond the firebrick area. A coal bed of (ideally) 1” to 2” should be established to achieve optimum performance. 6. This unit is designed to function most effectively when air is allowed to circulate to all areas of the firebox. A good way of achieving this is to rake a small (1” to 2” wide) “trough” in the center of the coal bed, from front to back, prior to loading the fuel. 7. Once fuel has been loaded, close the door and fully open the air inlet control, until the fire is well established (approximately 20 minutes), being careful not to over-fire.

Notice they say here and in other locations, not to over fire the wood stove, but no where that I see is that defined.

The best I see is:
<<5. Add larger pieces of wood as the fire progresses, being careful not to overload. Do not fill the firebox beyond the firebrick area.

So how would following that direction affect your use of the stove?


Overfiring is a real concern. Not only could it start a fire, but it can cause warping or damage to steel parts, firebrick or whatever.

In general I'm a big fan of following the manufacturer's instructions and directions.

Where did you get the 600 degree maximum operating temperature guidance? And where was that temperature supposed to be measured? And where are you measuring the temperature, and with what?

Personally, in my 30 year old steel wood stove, I use a Bacharach "Tempoint" thermometer inserted through a hole in the flue pipe. This is an excellent thermometer left over from my days as a furnace and gas fireplace repairman --- it measures temperatures up to 1000 degrees. I'll operate my wood stove with temperatures up to 700 degrees, 600 being my preferred upper range.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=bacharach++tempoint&_sacat=0


Most fan switches are designed to turn on a fan at the modest temperatures you have found. Limit switches can be found that turn power OFF at much higher temperatures. You COULD conect a 600 degree limit switch up to a low voltage (24 VAC) single pole, double throw relay. That way, you'd only have low voltage going to the limit switch attached to your wood stove. If the temperature gets to the 600 degrees, the limit switch would open, shutting off the low voltage relay, and you'd have the fan connected to the normally open pole of the relay, so it would then turn on.

 

[Hogwildz]

I'm thinking you meant sweeping device.
You basically have two options. A brush & rods. Many hear preach poly brushes, I have both poly & steel, both work. You can do from top down or bottom up if you go through the T. Just make sure to inspect the cap & top real well, as that is where a lot of build up starts.

Or you can buy a sooteater with rods for it and go bottom up or top down with that.
All the above is a matter of preference.

 

[wooduser]

Thanks, but still confused why these products are designed for a temp so much lower than what my stove is running.

FAN switches are typically used to turn fans ON when a heat exchanger warms up to an acceptable minimum temperature so that cold air isn't circulated, and designed to turn OFF when the heat exchanger has cooled off, so that the maximum heat has been extracted without circulating cool air. To dom that the fan switch turns ON at some temperature like 120 degree and to turn off at some temperature like 100 degrees.

A LIMIT SWITCH is a safety switch designed to protect the stove and property from an excessive or dangerous temperature. They are designed to turn power through the switch OFF if the temperatures reaches that dangerous point, and usually to turn the power back ON when the temperature declines to a safe level.

You want to operate your fan like it was a limit switch.

 

[wooduser]

Ahhhhh ok. Let me offer you some soothing words to that worry.
I assume you are using a a magnetic stove pipe thermometer? You are using it on the stove top?
You can't have a chimney fire unless: 1. you are burning wet wood that is not ready to be burnt. Think anything over 20-25% moisture content. 2. Your draft sucks, and your smoldering the wood while it burns, or actually doesn't burn real great. 3. You don't regularly inspect and sweep your stack, even a few times a season till you get a feel for if your burning habits are good or not, will dictate whether a build up or not to catch fire.

Burn good dry wood. 600-650 with some peaks at 700 is not un-normal for that stove. If you are at 600 you are golden. You can't go by the magnetic thermo, just use that as a reference only.

You are achieving a temp, that you should be shooting for.

I follow your advice in general, and in general it's reasonable advice.

In reviewing the operating manual for that fireplace, the manufacturer's appear to recommend not loading the firebox beyond the level of the firebrick. I'm guessing that if you follow that guidance you wont't be "overfiring" the stove as defined by the manufacturer. And a chimney fire isn't the only hazard from overfiring a stove. Damaging the parts on a woodstove by overfiring is easy enough to do, especially with temperatures above 600 degrees.

Personally, I find 600 degrees as a stack temperature a useful maximum temperature to aim for, although I'll go to 700 degrees if I'm watching the stove.

I wouldn't want to leave a totally untended stove operating at 600 degrees when people are asleep. You can't really know how high temperatures may spike.

I suggest that the objectively safe thing to do is to follow the manufacturer's recommendation which appears to be to not load the firebox above the level of the firebrick. That would appear to conform with the manufacturer's recommendation not to "overfire" the stove. I'd be interested to know the stack temperature that results when that guidance is followed.

 

[Hogwildz]

I follow your advice in general, and in general it's reasonable advice.

In reviewing the operating manual for that fireplace, the manufacturer's appear to recommend not loading the firebox beyond the level of the firebrick. I'm guessing that if you follow that guidance you wont't be "overfiring" the stove as defined by the manufacturer. And a chimney fire isn't the only hazard from overfiring a stove. Damaging the parts on a woodstove by overfiring is easy enough to do, especially with temperatures above 600 degrees.

Personally, I find 600 degrees as a stack temperature a useful maximum temperature to aim for, although I'll go to 700 degrees if I'm watching the stove.

I wouldn't want to leave a totally untended stove operating at 600 degrees when people are asleep. You can't really know how high temperatures may spike.

I suggest that the objectively safe thing to do is to follow the manufacturer's recommendation which appears to be to not load the firebox above the level of the firebrick. That would appear to conform with the manufacturer's recommendation not to "overfire" the stove. I'd be interested to know the stack temperature that results when that guidance is followed.

We are talking 600 degree stove top temp, not stack temp. Loading to firebricks is suggested as some overzealous owners can bang the splits into the burn tubes or break the baffle board. We are talking about a wood stove here, not a fireplace. My insert peaks to 700ish every night during 24/7 burning season, settling at a 600-650 cruising temp, and that does not harm the stove. If the stack temp was that high, then I might be concerned, but again we are talking stove temp, not stack temp. Very few manufacturers list an "overfire" stack or stove top temp, and they do that on purpose.
No where in his manual will you find an overfire temp. 600 degrees stove top temp is prime running temp, and no where near an overfire, nor hurting the stove.

 

[wooduser]

We are talking 600 degree stove top temp, not stack temp. Loading to firebricks is suggested as some overzealous owners can bang the splits into the burn tubes or break the baffle board. We are talking about a wood stove here, not a fireplace. My insert peaks to 700ish every night during 24/7 burning season, settling at a 600-650 cruising temp, and that does not harm the stove. If the stack temp was that high, then I might be concerned, but again we are talking stove temp, not stack temp. Very few manufacturers list an "overfire" stack or stove top temp, and they do that on purpose.
No where in his manual will you find an overfire temp. 600 degrees stove top temp is prime running temp, and no where near an overfire, nor hurting the stove.

You are making assumptions about how the manufacturer specifies the operation of the stove. I don't know how the operation of the stove will be affected by keeping the fuel load from rising above the firebrick. They may, and they APPEAR to be defining a fuel load above that level as an overfiring condition.

Your stove is your stove, and someone else's stove perhaps should be operated to a different standard. I suggest that this stove appears to be designed to operate with a limited fuel load, perhaps to avoid an overfiring condition. I have quoted the words of the manufacturer's operating manual as a reference.

And frankly I can't comment of the difference between "stove top temperature" and stack temperature, because I've only been measuring stack temperature for the last thirty years! Don't know from stove top temperature!

 

[Hogwildz]

I follow your advice in general, and in general it's reasonable advice.

In reviewing the operating manual for that fireplace, the manufacturer's appear to recommend not loading the firebox beyond the level of the firebrick. I'm guessing that if you follow that guidance you wont't be "overfiring" the stove as defined by the manufacturer. And a chimney fire isn't the only hazard from overfiring a stove. Damaging the parts on a woodstove by overfiring is easy enough to do, especially with temperatures above 600 degrees.

Personally, I find 600 degrees as a stack temperature a useful maximum temperature to aim for, although I'll go to 700 degrees if I'm watching the stove.

I wouldn't want to leave a totally untended stove operating at 600 degrees when people are asleep. You can't really know how high temperatures may spike.

I suggest that the objectively safe thing to do is to follow the manufacturer's recommendation which appears to be to not load the firebox above the level of the firebrick. That would appear to conform with the manufacturer's recommendation not to "overfire" the stove. I'd be interested to know the stack temperature that results when that guidance is followed.

We are talking 600 degree stove top temp, not stack temp. Loading to firebricks is suggested as some overzealous owners can bang the splits into the burn tubes or break the baffle board. We are talking about a wood stove here, not a fireplace. My insert peak to 700ish every night during 24/7 burning season, settling at a 600-650 cruising temp, and that does not harm the stove. If the stack temp was that high, then I might be concerned, but again we are talking stove temp, not stack temp. Very few manufacturers list an "overfire" stack or stove top temp, and they do that on purpose.
No where in he manual will you find an overfire temp. 600degrees stove top temp is prime running temp, and no where near an overfire, nor hurting the stove.

You are making assumptions about how the manufacturer specifies the operation of the stove. I don't know how the operation of the stove will be affected by keeping the fuel load from rising above the firebrick. They may, and they APPEAR to be defining a fuel load above that level as an overfiring condition.

Your stove is your stove, and someone else's stove perhaps should be operated to a different standard. I suggest that this stove appears to be designed to operate with a limited fuel load, perhaps to avoid an overfiring condition. I have quoted the words of the manufacturer's operating manual as a reference.

And frankly I can't comment of the difference between "stove top temperature" and stack temperature, because I've only been measuring stack temperature for the last thirty years! Don't know from stove top temperature!

No where in the manual does it say loading above the fire brick line is an overfiring condition. It merely says do not overfire the stove. A load level does not indicate an overfiring condition.

Congratulations on measuring stack temps for the last 30 years, and not knowing the difference between stack temp & stove top temp. That is truly something to boast about. There is a big difference, and if your stack temp is 600-700 degrees, your stove top temp may be a couple hundred degrees hotter than that, and you may be very well overfiring your stove. Yes, there is a big difference. The manual is a reference, and not a wood burning bible. They keep it vague because every application & system is different. Yes there is some common ground between all stoves, but the manual is kept limited in info for a reason.

As has been said many times, just because a person claims to have burning for 20,30,40,50 years, does not necessarily mean they have been using the best burning practices. At 600 degree stack temp, you have a bunch of heat going up and out, that is fact.

 

[wooduser]

We are talking 600 degree stove top temp, not stack temp. Loading to firebricks is suggested as some overzealous owners can bang the splits into the burn tubes or break the baffle board. We are talking about a wood stove here, not a fireplace. My insert peak to 700ish every night during 24/7 burning season, settling at a 600-650 cruising temp, and that does not harm the stove. If the stack temp was that high, then I might be concerned, but again we are talking stove temp, not stack temp. Very few manufacturers list an "overfire" stack or stove top temp, and they do that on purpose.
No where in he manual will you find an overfire temp. 600degrees stove top temp is prime running temp, and no where near an overfire, nor hurting the stove.

No where in the manual does it say loading above the fire brick line is an overfiring condition. It merely says do not overfire the stove. A load level does not indicate an overfiring condition.

Congratulations on measuring stack temps for the last 30 years, and not knowing the difference between stack temp & stove top temp. That is truly something to boast about. There is a big difference, and if your stack temp is 600-700 degrees, your stove top temp may be a couple hundred degrees hotter than that, and you may be very well overfiring your stove. Yes, there is a big difference. The manual is a reference, and not a wood burning bible. They keep it vague because every application & system is different. Yes there is some common ground between all stoves, but the manual is kept limited in info for a reason.

As has been said many times, just because a person claims to have burning for 20,30,40,50 years, does not necessarily mean they have been using the best burning practices. At 600 degree stack temp, you have a bunch of heat going up and out, that is fact.

Thanks for your comments.

Recommending that the firebox be loaded to a limited level is the only objective guidance on how big a fire to build. We agree that there is no specific objective guidance as to what an overfired condition is. So I continue to suggest that the recommended amount of fuel is the best guide available.

You are happy firing your stove to a temperature of 600-700 degrees by measuring the surface temperature of the stove. My stove manufacturer provided me with no such guidance, so I decided for myself what was reasonable. A stack temperature of 600 degrees is a good maximum that I aim for. If a fire boosts the stack temperature to 700 degrees I'm looking to cut that down.

You seem to have great confidence in your recommendations, having never seen either stove. I suggest that may be misplaced in both cases.

I used to analyze the combustion of gas furnaces and boilers after conversion burners were installed. A conversion burner allows a very wide range of fuel and combustion air to be directed into the equipment, making it necessary to use instruments to test the combustion for satisfactory levels of CO2, oxygen, stack temperature and carbon monoxide. All of these characteristics can vary widely, and usually the combustion air and gas input can be adjusted to bring about a safe and efficient operating condition. So for me, using a stack temperature as a guide to operation is natural, and I happen to have a good thermometer to use for that purpose.

Perhaps I'll buy a thermometer for measuring the stove surface temperature and compare that with the stack temperature. It sounds like your time spent using a wood stove has been spent knowing the stove surface temperature but not the stack temperature of the actual combustion products.


<<The manual is a reference, and not a wood burning bible. They keep it vague because every application & system is different. Yes there is some common ground between all stoves, but the manual is kept limited in info for a reason.

I usually hear comments like that from people who are substituting their own judgement for that of the people who designed their equipment.

<<As has been said many times, just because a person claims to have burning for 20,30,40,50 years, does not necessarily mean they have been using the best burning practices. At 600 degree stack temp, you have a bunch of heat going up and out, that is fact.


Well, I'l agree that that is an OPINION. A fact would be to do a combustion analysis of the flue gasses and stack temperature, which you have never done and which I haven't done with my stove. Actually, running 600 degrees is hotter than I prefer to do. It's really the maximum I'd see before taking active measures to reduce the stack temperature. My main concern is overfiring the stove. At 700 degrees I'd take positive action to cut down the temperature, at 600 degrees I'd typically let it burn down further on its own.

I don't suppose you have a reference to someone who has done that kind of combustion analysis on different stoves, allowing the actual efficiency to be determined? That's the practical real way to test and determine efficiency that I know about. My opinion and experience is my opinion and experience, and the same for you, my friend.

Do you have any references to recommended stack or stove surface temperatures? I've never seen any guidance on that, but perhaps it's out there somewhere. Comparisons between stove surface temperature and stack temperatures and recommendations on either or both of those I'd be glad to see as well, if you can refer me to that kind of information.

I'll look around and see if I can find information on recommended stack temperatures for gas, oil, coal and wood fired equipment. Perhaps there's some useful guidance out there somewhere.

I suggest that with most fuel burning equipment, measuring surface temperature isn't of much use, since appliance surface temperatures usually aren't exposed to the fire. Stack temperature is, I suggest, a far more widely used way to understand the heat being produced by the appliance.

But surface temperature on a typical wood stove may indeed be useful, since if you choose a suitable place to measure the temperature it ought to reflect .the combustion that is taking place. Even so, measuring the surface stack temperature would seem to me to be a more sensitive guide to what is happening.

Thanks again for your interesting and useful comments, bringing up ideas I hadn't considered in detail before.