2 Teeth?

Has anyone had success running 2 teeth? Im currently running 3 teeth and 3 1/2 air. Seems to be holding up fine, no outfires yet. Thinking about turning it down another and save some more coal.

Running at very low feed rates tends to keep the fire deep in the pot, and is harder on the burn plates. With good coal 3 teeth should be fine, but I would not go any less.

If it runs fine on 3 teeth with the timer at 2 minutes every half hour, it would probably also run fine on 4 teeth with the timer at 1.5 minutes every half hour. Both combinations consume 12 lbs of coal in 24 hours, which is what I have found to be the "floor" for a reliable fire.

Depending on your domestic hot water consumption, you may or may not see a decrease in coal consumption from 4 to 3 teeth.

let us know how it works out.

I was planning on leaving it on 3 for a couple weeks to gauge usage before making any more adjustments. I think if I was going to have an outfire, it would have been sunday or yesterday. Just about 90 out with very high humidity. Monitoring my draft, it was close to noth8ng the last 5 minutes before another timer cycle. You're comment about the fire burning low in the pot makes sense now. I have noticed that at 3 teeth the auger tube is now warm.

I initially thought that this thread was about the girl I picked up the other night

plumber wrote:I have noticed that at 3 teeth the auger tube is now warm.

"If excessive heat is detected on the surface of the aluminum coal pipe outward of the boiler jacket, the rate of feed should be increased immediately to keep from damaging this pipe, worm, or other components of the pot assembly." EFM manual (http://efmheating.com/index.php/efm-online-manuals) at page 7. Cutting the air a bit could also help.

FWIW, 3 teeth is the lowest feed setting shown in Table 1 on p24 of the manual. It gives pretty limited output - enough BTU's for around 1.5 gpm of DHW in real time. I wouldn't bother with trying to go lower than that.

Mike

If you're not careful to check for a very overheated coal pipe at 3 clicks, this is what can happen.

What is too hot? I currently have an aquastat on the tube set at 150.

At efm, we ran at 10 teeth and the pipe was always cool enough to lay your hand on it. I don't know what is too hot.

At 4 teeth tbe pipe was a little warmer than room temperature, at 3 teeth its warm. Its not hot, like crap I just burned myself hot, but its definitely warm. Forgot I have a IR gun. Its 130 right now.

A relative runs at 1 tooth in the summer and can do it. Unless you're constantly overheating and shutting down because of missed timer cycles, why not leave it at 4?

It runs fantastic at 4 teeth, im just trying to be cheap and save coal.

Well surprising to me I burned exactly the same amount of coal on 3 teeth than I did on 4 teeth! ?!
I'm averaging 17 lbs per day, and doesn't seem like I'm going to get any lower on that. Well, I set it back to 4 teeth as the boiler seemed cooler there. Less wear and tear and simplicity. Oh well!

Sometimes you just can't get any better than good , then good is good enough !

It takes so many BTU to heat the water. As I see it, you will take twice as long at 2 teeth as at 4 teeth. Maybe more stack loss at 4 and maybe not enough BTU at 2 and just warm air going up the flue. I'm sure it's close, as you said.

Rob R. wrote:Depending on your domestic hot water consumption, you may or may not see a decrease in coal consumption from 4 to 3 teeth.

plumber wrote:Well surprising to me I burned exactly the same amount of coal on 3 teeth than I did on 4 teeth! ?!