Hotblast 1500. Shop use Blower cycle

[solar07]

Hello all,

I have used this forum for good reads for some time however, decided to finally join today. I finished building my pole barn a couple years back and chose wood/coal as my heating source. I got a great deal on a hotblast 1500 at rural king last year for black Friday so I snagged it. 800 bucks. From the reviews I've read on here it is far from perfect but I'm hoping it will do in my shop. I'm just getting into the insulation process however, projects have demanded use of my shop in the meantime. obviously it takes everything the hotblast has and then some to keep my 40x60 barn warm on a nice 15 degree Ohio day. I know once the insulation is done (still deciding on the how), heating the barn will be a completely different story.

I am looking forward to making this stove the best it can be. I think I've come to the right place. this is for shop use, stand alone, so not inecessarily a home or hooked up to a furnace of sorts. I just utilize the two blowers that come with the hotblast 1500 to push air into the two plenums of the stove. I have round duct of one that goes over to anot insulated wood shop and man cave section of the barn and another ducted into the main barn splitting off into a ceiling high register pointing downward. I haven't decided if this is the best setup yet. when in the main shop I end up detaching the wood shop man cave route and just elbowing that heat directly into the barn.

My first noticeable issue is, blowing cycling. my blowers don't seem to want to come on at first until the stove reaches around 400 degrees (per the magnetic temp guage) in the fire box. once I get the blowers to finally kick on they will power cycle 20 plus times for 20 seconds or less each cycle. Once the stove has been on for around an hour they will finally stay on. If the temp.drops below 275/300 they will shut off and sometimes start to cycle again as mentioned above. I have to keep the box at pretty high temps and the chimney at even higher temps to get everything to function properly with wood.

From what I have seen and researched, this stove powers on the blowers based on the temp reading of a thermo disc in the back. This disc is not adjustable and I have not a clue what the settings of it are. I am guessing the cold air being returned from my shop is lowering the temp on this disc too quickly. This is just a guess. Thoughts?

I have been looking on line and seen there are fan and limiter switches as well as adjustable disc thermos. I do not however know which would be the best to go with and how to determine which would be the right temp specs for my stove. it seems they come with different ranges. I don't know if US stoves makes one for my specific application .

This should be a good start for my questions and hopefully this can evoke into a nice build thread to make this a nice shop stove.

Thank you all.

 

[laynes69]

The older units took a 5.5" probe limit/control and we're fully adjustable. Ours was set at 90 off and 135 or so on. It would almost run continuously with these settings. I modified ours in the end and added a 3rd 8" duct between the two and removed the 2 blowers for a large multispeed blower. The difference was night and day. I forgot to add, the colder the air going in, the more it will cycle.

 

[dozerdean]

The older units took a 5.5" probe limit/control and we're fully adjustable. Ours was set at 90 off and 135 or so on. It would almost run continuously with these settings. I modified ours in the end and added a 3rd 8" duct between the two and removed the 2 blowers for a large multispeed blower. The difference was night and day. I forgot to add, the colder the air going in, the more it will cycle.

When u added the 3rd 8" pipe did your unit cycle more? I added the bigger blower & added the limit control in the 8" pipe which makes it cycle more.so adding the 3rd pipe pushed more air into duct work? Did it cool off the unit faster?

 

[laynes69]

When u added the 3rd 8" pipe did your unit cycle more? I added the bigger blower & added the limit control in the 8" pipe which makes it cycle more.so adding the 3rd pipe pushed more air into duct work? Did it cool off the unit faster?

No, but I kept the off temp lower on the limit, if it was too high, it would shut off quicker. With a good hot fire, I could have the house to 80 in no time. It didn't cycle until coaling stage.

 

[solar07]

The older units took a 5.5" probe limit/control and we're fully adjustable. Ours was set at 90 off and 135 or so on. It would almost run continuously with these settings. I modified ours in the end and added a 3rd 8" duct between the two and removed the 2 blowers for a large multispeed blower. The difference was night and day. I forgot to add, the colder the air going in, the more it will cycle.

Hey I see you are in Ohio too?

I have read about your setup here and there but all the attachments always say missing. Do you have some pics and explanations of your setup? I'm curious of your third duct model and I saw menation of the removal of the rear plug?

Would it be your suggestion to move to a limit switch ?

It sounds like dozerdean relocated to the heating duct?

Thank you kindly for your time to reply.

 

[laynes69]

I put my old hotblast out of commission in 2007 when I upgraded, and sold it a few years ago. I do remember it was a 5.5" Honeywell limit switch which was mounted on the left rear if you were looking at the back of the furnace. I didn't use the door damper, and the rear plug was removed and I had a forced draft fan installed which was worthless. However, having the rear plug out allowed for some air above the baffle which did help burn a little hotter and cleaner.

 

[solar07]

So you just removed the plug and that was that? Is this something that would help in my shop?

Any pics of the 3rd duct? wondering if I should look into that as well.

 

[cantoo]

I used to use a wood burning Hotblast. I changed out the twin blower for a large squirrel fan. I also remove the disc and put a couple of washers behind it to limit the cycling on and off. Have you considered hanging tarps to section off the shop if you don't need to heat the whole thing?

 

[laynes69]

I had a blower where the plug was, however I didn't use the blower and it remained open for air. Sorry, I don't have any pictures of it anymore. Opening up the top helped quite a bit.

 

[Iaff113]

Try putting foil tap on all the holes on the switch housing. My fans kick on around 100 125


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[solar07]

Oh that's a good thought . there is a big hole on that housing. I thought about doing something like that but wasn't sure what with. I'll try that before investing in a new adjustable thermodisc .

I see a lot of talk of doing something with the cold air return on these or linking it to the blower some how. is that even worth exploring since I'm heating my shop?

 

[dave_dj1]

It sounds like a bad Honeywell switch to me. If I was only using this in my pole barn I would bypass the switch and have the blower run constantly while I was burning otherwise you may want a new switch.
The only one I ever saw short cycle like that was replaced and all was good.

 

[Iaff113]

When I had my hotblast set up at my other house i just put the blowers on a regular light switch to control them that way


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[solar07]

I have a thermodisc now that does not have adjustments . ....

 

[Rachel P]

I have a thermodisc now that does not have adjustments . ....

We just bought the hotblast and replaced the thermodisc for it was kicking on and off to much. We put in the honeywell adjustable limit control switch, now fan kicks on and off as it should. We were told be sure to get an 11inch one. We also removed the plug from the back and that seems to have helped with the draft. Now we want to replace the blower, The blower on it 550 cfm puts little air into the registers. I see people say get a 1/3hp but not sure what type or what size the shaft is I should look for. Anyone know? Thank You.

 

[Rachel P]

The older units took a 5.5" probe limit/control and we're fully adjustable. Ours was set at 90 off and 135 or so on. It would almost run continuously with these settings. I modified ours in the end and added a 3rd 8" duct between the two and removed the 2 blowers for a large multispeed blower. The difference was night and day. I forgot to add, the colder the air going in, the more it will cycle.

Wanting to also upgrade the blower on the Hot Blast furnace we just purchased. I have no idea where to start. I read get a 1/3hp. Will any blower work as long as the shaft is the same size? Also trying to figure out the size of the shaft. The unit we got is the smaller one with only one blower attached. Thank you.

 

[greenskeeper]

since you're heating a shop why not junk the thermostatic switch and just run an on/off switch for the blower when you are in the shop and burning?

 

[cantoo]

Rachael, do some searching on here for "hotblast' and you should be able to find some info. Most don't just replace the factory motor, we remove it completely and install a bigger fan. Most of us that replaced them just used furnace blowers and fans from other furnaces. I bought mine for $25 used from a changeover to propane unit. I have pictures on here somewhere of my fan and blower but not sure where now.
This is a good thread.
http://www.arboristsite.com/community/threads/hot-blast-enemy-or-friend.268178/

 

[Need2Saw]

the cold return air is absorbing heat from the firebox at a rate faster than the fire is burning, this causes the fan to cycle on and off more than normal. Once the barn is up to temp the fan will cycle regularly.
My hotblast also takes awhile for the fan to turn on if i start a fire in a cold stove, after that its cycle times are dependent on the size of the fire within.
Also, more air flow through the furnace will increase the fan cycle rate. A larger fan or larger ductwork will cycle the fan more if all other variables are the same (firing rate, air temperature)

 

[Rachel P]

Rachael, do some searching on here for "hotblast' and you should be able to find some info. Most don't just replace the factory motor, we remove it completely and install a bigger fan. Most of us that replaced them just used furnace blowers and fans from other furnaces. I bought mine for $25 used from a changeover to propane unit. I have pictures on here somewhere of my fan and blower but not sure where now.
This is a good thread.
http://www.arboristsite.com/community/threads/hot-blast-enemy-or-friend.268178/

Thanks for your reply.