Blower problem on a SF3100

backwoods

New Member
Jan 16, 2020
4
ohio
New guy here ……. I have a new (still on the pallet) Shelter SF3100, that I bought and installed about 4 months ago. I bought it at an online auction, (local to me), unfortunately not knowing I was making a big mistake after the problems I am having with it in about 2month usage, cracks around the door, seeing warpage on the inside panels and now this.
My main problem "currently" is that the blower on the dang thing runs (blows heat) for a minute, if I am lucky, then off for about 30 seconds then back on for a minute and so on . I installed the factory thermostat that came with it and have tried everything from having it as hot as I can get it loaded with plenty of wood , to just a normal bed of coals and a few pieces of wood and still NO change …… What am I doing wrong ? Please, any help is appreciated .
 

brenndatomu

Minister of Fire
Aug 21, 2013
5,340
NE Ohio
Yeah that sucks that you got stuck with one of those POS.
Did the blower run longer before?
Is it wired to run on low speed?
Is the blower control switch working right?
What is your static pressure like?
Does it have an air filter, if so, what kind/type?
 

backwoods

New Member
Jan 16, 2020
4
ohio
Yeah that sucks that you got stuck with one of those POS.
Did the blower run longer before?
Is it wired to run on low speed?
Is the blower control switch working right?
What is your static pressure like?
Does it have an air filter, if so, what kind/type?
Yes it is a POS ! I do NOT recommend this stove to anyone and I never will. These stoves should ALL be recalled and sent to the scrap yard!! My old TSC Hot Blast was way better and I had it in use for 8 years and I used her hard during those 8 years !
The blower has not changed since the first day I started using it, a minute running and off about the same .
Not sure what you mean by low speed... I wired it (2 wires) according to what the so called "instructions" called for . I even bought another thermostat to see if it would make any difference and it gave me the exact same results .
It has a Hi and low setting (toggle) for the blower motor, with little difference between hi or low when switched between the two.
Static pressure ? Uh oh, now I am feeling lost, in other words I am not sure what you are talking about .
It has a 20x25x 1" Honeywell micro defense merv 8 filter installed
 

brenndatomu

Minister of Fire
Aug 21, 2013
5,340
NE Ohio
Static pressure is the tiny little bit of back-pressure that your ductwork causes...it can slow the air down as it passes through the furnace, which allows enough time for heat to transfer, which will keep the blower running and your house warm. A higher MERV air filter like you already have can help too.
If you have dampers on the ductwork try closing them down some...there is a delicate balance between closed enough to keep the blower running, and enough air flow to heat the house. Or you may be able to close the heat registers down some to accomplish the same thing.
The exact number of your static pressure isn't that important IMO, (+.2" WC is common) in my experience if you can pick up 40-50* as the air passes through the furnace, it will work. If you want to actually check the SP, buy a Dwyer Mark II model 25 manometer...it will check SP, and then you can use it to check the chimney draft too...which very well may be part of your issue also. "Too high" draft causes the stove to overfire (not that those units need any help!) and all your heat to go up the chimney. A common normal wood furnace draft reading would be -0.04" to -0.06" WC on the manometer.
Those Dwyers can often be bought on fleabay for $25-$40 or so...just make sure they are complete with the hoses, fittings, and the red gauge oil...that oil is a little spendy to buy separately.
 

SidecarFlip

Minister of Fire
Is there a thermal breaker on the fan motor???
 

3fordasho

Minister of Fire
Jul 20, 2007
901
South Central Minnesota
Can you get us a pic of the fan switch? Is it one that sticks through the plenum and hangs in the air stream or one that just contacts the plenum sheet metal? I've found ones hand in the air stream don't have any thermal mass and are subject to cooling too quick when the fan kicks on and if there is not a significant differental they will short cycle. Most of these will have a fixed 20F differential. Some have adjustable on/off points but probably not one that Shelter would provide. Ones mounted to the outside of the plenum sheet metal have worked better for me. YMMV. I've used a few adjustable units from Zoro.com that I've had good luck with - adjustable on point with 20F less off point.
 

backwoods

New Member
Jan 16, 2020
4
ohio
Static pressure is the tiny little bit of back-pressure that your ductwork causes...it can slow the air down as it passes through the furnace, which allows enough time for heat to transfer, which will keep the blower running and your house warm. A higher MERV air filter like you already have can help too.
If you have dampers on the ductwork try closing them down some...there is a delicate balance between closed enough to keep the blower running, and enough air flow to heat the house. Or you may be able to close the heat registers down some to accomplish the same thing.
The exact number of your static pressure isn't that important IMO, (+.2" WC is common) in my experience if you can pick up 40-50* as the air passes through the furnace, it will work. If you want to actually check the SP, buy a Dwyer Mark II model 25 manometer...it will check SP, and then you can use it to check the chimney draft too...which very well may be part of your issue also. "Too high" draft causes the stove to overfire (not that those units need any help!) and all your heat to go up the chimney. A common normal wood furnace draft reading would be -0.04" to -0.06" WC on the manometer.
Those Dwyers can often be bought on fleabay for $25-$40 or so...just make sure they are complete with the hoses, fittings, and the red gauge oil...that oil is a little spendy to buy separately.
No dampers installed .
I will try to measure the total length and diameter of the duct work that is in the house prior to the chimney ….. and chimney length as well.
Is it possible that not having enough distance/length of duct inside , before the chimney, cause poor static pressure? 90 degree elbows or should I have installed 45s ?
I will look online this weekend at your recommendation of the Dwyer systems.

thank you for the quick responses and you valued imput !
 

brenndatomu

Minister of Fire
Aug 21, 2013
5,340
NE Ohio
No dampers installed .
I will try to measure the total length and diameter of the duct work that is in the house prior to the chimney ….. and chimney length as well.
Is it possible that not having enough distance/length of duct inside , before the chimney, cause poor static pressure? 90 degree elbows or should I have installed 45s ?
I will look online this weekend at your recommendation of the Dwyer systems.
thank you for the quick responses and you valued imput !
Seems there is some confusion of terms here...ductwork is what carries the warm air to your house.
The pipe connecting to your chimney is stovepipe.
Static pressure is positive pressure related to the ductwork..."draft" is the negative pressure that makes the chimney and therefore the firebox work.
The Dwyer can measure both.
Once you know the specs on your chimney system, or even better, an actual draft reading, it can be determined if you need to worry about changing your stovepipe and/or elbows setup.
 
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