Secondary burn furnace temps/limit switch settings

[Ozark Woodburner]

I have a secondary burn wood furnace that is installed as a stand alone unit. I'm wondering if my register temps of 100 degrees is common or kind of low? The furthest duct from the furnace is only 2 degrees lower than the first one, so I feel that's good. Looks like I'm losing about 30-40 degrees from the plenum of the furnace to the registers. Is this on par with others?

I'm also curious as to what the limit switch adjustment others are using and having best luck with. Mine is on at 160 degrees, off at 115 degrees. Factory setting was 150 on/115 off. The ductwork is insulated once it hits the crawl space of my home, but from the furnace to that point is 12 feet of un-insulated ductwork. The blower speed was set to medium. When it was set to high, the register temp was rarely over 90 degrees, so I picked up 10 degrees roughly by slowing the blower down.

It is keeping my home quite comfortable, just tinkering with the fine tuning of this.

Thanks.

 

[laynes69]

Sounds about right to me. I've seen up to 120 and as low as 90 from the registers. All depends on where the cycle is at.

You have the Napoleon right? Did you finally get your problems take care of? That furnace has many characteristics of the Caddy, the only other thing that will help is keeping that heat exchanger clean.

 

[Ozark Woodburner]

Yes, the HMF150. And yes, I finally got Napoleon to send me a back panel (where the air damper slides open and closed). I installed it this summer and it has performed flawlessly on a very reasonable amount of 2 year old hardwood.

 

[Ozark Woodburner]

Laynes, don't you have your limit switch on/off setting adjusted quite a bit lower?

 

[STIHLY DAN]

Mid winter I have mine on @ 105 off at 90. Shoulder season its 120 and105. But that's for low speed, on a call for heat the furnace turns itself on high. Which is not very often. The lower temps lets me squeeze every last bit of heat out of the coal bed.

 

[laynes69]

Yeah, I lowered ours to 125 on and around 100 off. I get much more heat this way, and I find it doesn't make a difference whether it's higher or lower as far as operation.

 

[Ozark Woodburner]

I've been thinking about lowering mine too. The manual says to leave it at 150/115 for best efficiency. I could always reset to factory settings if I don't like it.

 

[Ozark Woodburner]

Well, I lowered it to 135on/100off last night. Register temps maxed out at 110 degrees, blower ran a lot more, a few degrees warmer than normal this morning though.