OWB Owners, what's your set point?

[Scootermsp]

Moved the set point on the 5036 from 175F to 180F yesterday. Just starting to get cold enough to notice I'm using more wood now. When night temps go to low 20s then I will move the set point up to the 185F factory setting. Does anyone run it higher on a regular basis? The CB owners manual states you can safely set it up to 195F. I find that lowering the set point in Fall and Spring can add up to some significant wood savings.

 

[Slick]

5036 at 175 right now all day long, easily keeps up and has on/off cycles so I'll keep it there until it's really cold and furnace has to run a long time. I judge it by the house furnace, if it runs a long time it's time to raise it but it's barely running now.

 

[nathandrews]

I have the same model. I find lowering it when temps are higher saves wood as well. I use 185 as my upper limit to minimize the chance of a boil over if the temp continues to climb after the damper closes. I've seen mine hit 190+ when I've got a big fire going. I'm familiar with programming this thermostat from another industrial application. I've been considering increasing the differential to see what effect it has. I suspect it might dramatically increase the chance of the fire going out between cycles, but can't decide what it might do to wood usage.

 

[AIM]

I run mine at 140°
My house can even be heated at 120° but my garage needs the higher temp. I play with it quite often and have observed that the higher temp simply equals more wood.
I don't mind the fact that the furnace blower runs longer and more often. Seems to even out the heat.

 

[Windwalker7]

Setpoint at 150* on the Shaver right now.



I may go up to 160* when it gets colder, then again, maybe not.

 

[eyolf]

I favor lower settings: a physics teacher explained to me, but I didn't retain it well, except that the system is more efficient at a little lower temps.

A lot of older OWB's with non-adjustable aquastats were on at 140-145, off at 165-170.

 

[Scrapiron]

My Taylor is set to come on at 160. Turns off around 170.

 

[Blazin]

I'm at 185 right now, when it hits the teen's I'll kick it to 195. If it was just hooked to my house 175 would be fine, but the the other run goes to my 81 year old mother's house.....they like to twist the thermostat at that age I guess. LOL! Her house has hot water baseboard and the higher temp on the OWB makes for a quicker heat in the house I've found.

 

[builder1101]

winter time, on 165, off 195
summer time, on 165, off 170
winter is higher and longer as damper opens more often
summertime lower and shorter, keeps fire from snuffing out.

cb's are locked, can't change the deg difference, oem dywers you can change.
hold set for 8 seconds to see if you can change r0....

 

[Woodcutteranon]

My Hardy is set at 150 to 170. I am afraid to start playing with the settings as I would probably become obsessed with it just like everything else involving my OWB, saws, firewood etc. I need a break

 

[oneoldbanjo]

My Woodmaster came with a setting of blower off at 170 and blower on at 160. This small spread didn't seem to ever let the fire get burning very hot and I got a lot of creosote inside the furnace - so I changed the spread to 20 degrees and my temps were then 170-150. That seemed to work fine - but I did notice that sometimes I had 2 feet of flame going out the stack when the fire got going too well.

So far this year the temps have been really mild this year in the Cincinnati and Northern Kentucky area and I am trying my set points at 155-140. The furnace is using lots less wood and it spends a lot of time just smoldering.....and the inside of the firebox has a thick coat of creosote built up on the inside. This weekend it is supposed to get cold and I will probably let coals burn down and allow the fire go out, shovel out the ash, then change the set points back to 170-150 and build a new fire with well seasoned wood.....and burn out the creosote accumulation.

I don't see any reason not to change the set points as the weather changes and the heat demands change. I have never had a fire go out with dry wood, and I think that with well seasoned wood it is fine to have the on/off set points pretty close so as not to get too hot of a fire going which will send a lot of heat out the stack. With wet wood it may be necessary to spread the set points out a little bit to get some heat inside the furnace between cycles.

 

[ghitch75]

i have found that if i have the diff. any closer than 20f it is off and on like a yoyo and it eats wood......i keep mine at 150 on 185 off...it only takes mine about 15min's to climb 35 degrees.....face cord lasts about 10 to 12 days in the coldest weather.....

 

[fletcher0780]

Heating 4000 ft with radiant floor and 800 ft with baseboard in NE CT

When daytime temps are 35* and up I set it at:
140 on - 145 off

When the temp drops to below 30* for extended periods I bump it up to:
170 on - 175 off

I think my radiant would work at 145 regardless of the outside temp, but that one zone of baseboard in the apartment above my garage needs 160* supply when it stays below 20* for two or more days in a row.

I might look into a more advanced controller that will adjust my setpoint based on outside temperature, but for now I need to work on cutting wood and adding insulation to my boiler.

 

[jcappe]

Mine (Woodmaster) is set at 160 off and 150 on right now. We are just starting to get mid 30's during the day and low 20s at night so I will probably bump it to 170 off and 160 on. I think it definately makes a big difference if you change the water temp when the weather permits.

 

[Butch(OH)]

I have played around with the settings on my 4400 WM for now the 4th year and I think that I save some wood at lower temps. I have never played with the spead between off and on though. Right now I am running 150-160 same as it came from the factory as it got cold last night.

 

[oneoldbanjo]

I have played around with the settings on my 4400 WM for now the 4th year and I think that I save some wood at lower temps. I have never played with the spead between off and on though. Right now I am running 150-160 same as it came from the factory as it got cold last night.

I only changed the spread settings from 10 degrees to 20 degrees to help reduce the smoke output. When my OWB was first installed I was burning the wood that was cut and stacked when I cleared the land to build my house. The wood was cut and stacked onto pallets that were setting right next to each other - no room for air movement and the stack was not covered. The wood sat this way for 3 years and was not well seasoned and was starting to rot. When I first got my OWB the spread was only 10 degrees and when the blower came on the OWB would smoke like crazy.......and just about the time the fire got going and started to burn without smoking the water temp would hit the upper set point and shut down....and then the OWB woudl begin to smolder and smoke again. I reset the spread to 20 degrees and the OWB burned much cleaner as the fire would get hotter and burn clean for a while.

Now that I am burning wood that is well seasoned as it has been in my wood shed for 2 years - I will reset the spread to 10 degrees and see how it does. This dry wood burns much cleaner than the old wet wood and it may not need the large 20 spread anymore. I am sure it will burn much more efficiently with a 10 degree spread - as the 20 spread very often allows the fire to get so hot near the end of the burn cycle that the flame is coming out of my stack and the water inside the boiler can be heard to be popping occasionally as it is starting to boil (even though the water temp is only 170 there must be hot spots where the water reaches 212).

 

[toyfarm]

Burnrite... kicks on at 160 and kicks off at 185. That's where it was when i got it and haven't messed with it since!

 

[mtfallsmikey]

Right now: 160/150...will move it up to 180/170 when it gets good and cold out...never run it higher than that.
Makes a good case for oversizing your HX's....size it to carry your heat loads at 140 deg. or so.

 

[NC4AB]

I upgraded to a 2 stage Ranco controller on my Hardy, right now it is set to keep the water between 145 and 160 by doing the following:

Damper opens if the temp gets below 155, closes at 160.
If the damper can't keep up the fan comes on a 145 and turns of at 155 and the damper stays open until 160.

Seems to save on wood by not running the fan unless you really need it. I have a data logger on the computer that records the temperature data and it makes a nice sine wave type curve. When I get home I can take a quick look at it and can see how hard the stove is working. If it gets really cold and I see that the stove is keeping the damper open most of the time I raise the cutoff to 170 to give me a little more heat.

And as Mtfallsmikey said, it helps to have an oversized water to air HX in the ductwork to use the lower temperature water.

 

[fletcher0780]

I upgraded to a 2 stage Ranco controller on my Hardy, right now it is set to keep the water between 145 and 160 by doing the following:

Damper opens if the temp gets below 155, closes at 160.
If the damper can't keep up the fan comes on a 145 and turns of at 155 and the damper stays open until 160.

Seems to save on wood by not running the fan unless you really need it, I have a data logger that records the temperature data, it makes a nice sine wave type curve, and I can when I come home I take a quick look at it and can see how hard the stove is working. If It gets really cold and I can see the stove is keeping the damper open most of the time I raise the cutoff to 170 to give me a little more heat.

And as Mtfallsmikey said, it helps to have an oversized water to air HX in the ductwork to use the lower temperature water.

I was considering a similar setup, but also adding an ambient air temp setting to the mix. What model Ranco did you use?