Blower problem

Well, the past month or so, my smaller combustion blower has been acting up, rattling, slowing down, etc...
I have taken it off, cleaned, lubed and put back on...about 2 or 3 times. Okay, tonight I get home, the smaller burner in my Hyfire is out, open the door, black coal completely off the grate and into the ash pan....CRAP, must have seized up the motor.

Took it apart, cleaned it, put it back on, fired it up, not real hot, barely glowing. Let it run, while I work on a different one...

Okay, I had bought a similar one at a local surplus shop, no flange, no specs, a little bigger squirrel cage, So, I custom cut a flange out aluminum, drill some holes by measuring the flange on the stove...pretty close, bend it up, hammer the opening to fit....oops, the blower is rectangle, the stove is square...already drilled the holes, the blower now mounts sideways, but fits right up!!

1.5 hours laters messing around with the blower.

I shovel some coal from the other side, bury it good, flip the switch, wait.....something starts glowing....more....more!!!

Holy Crap it's getting HOT, HOT...this thing is like a blast furnace!! Getting hotter, 400 degrees....500 degrees....600 degrees.....exhaust almost 300 degrees... Never had it that high! You could smell hot metal....I was ready to unplug the stove, but it started to settle down slowly. okay, turn on the fans to 100% to kick the heat upstairs and wash the stove, put a box fan on to move the heat around the basement.....finally after about an hour...back down to 400 degrees and stabilizing.... phew

I think the blower has a bit more CFM and is burning a bit hotter and better! Will check it and see how the ash looks later.
Seems to be burning fine.

You have the fire extinguisher handy???
Just kidding. My only question is why did it get so hot and then settle down? Did you make any changes other then to start the blower?

Yes, extinguisher was handy...

Since the one side flamed out, I had to restart it, and the whole grate ignited, until it burned out to ash. So it had almost a full grate of hot coals burning for a bit..I knew it just had to settle down after a period of time..

update this morning, burning great! Actually, I think its even better than before, the ash seems much finer. I think I am feeding it a bit more air...I talked to Jerry @ LL previously, he said it only requires 31CFM, not even sure what this blower puts out. But it's working for now.!!

With only the 90K side working, I really need to keep it cranked to keep the house warm, with both sides running, I can run at 50% or so and it keeps it as warm and still have some more capacity when/if needed when it gets cold.

Thanks..

Sounds good. On the Alaska I keep the combustion fan running full speed as well and adjust the feed to control the burn. I feel the higher combustion air flow results in a better and more complete burn.

With a larger combustion blower it may be a good idea using a manometer to compare stove draft to flue draft to be sure the stove isn't going positive .

Yes, already keeping an eye on it. Draft's Good! I think with the hotter burning temps, it is actually drawing a bit more. It's around .04-.05 with the baro at least 1/2 open.

I can't even get it down to .02 with the baro completely open by hand. That's how good the chimney draws.

Thanks!

WNY wrote:Yes, already keeping an eye on it.

Just to make sure there is no confusion here, Dave I think coalstoves meant you need to check the static pressure in the stove, you can only check this by drilling a small hole in the stove body. I usually do this just below the door and above the ash door. Then you can leave it or drill/tap for a 1/8" pipe plug and reinstall each time you check. The actual pressure in the stove can be positive which is not a good thing. A minimum for stove static pressure would be -.02"WC and you can adjust this by covering the combustion fan inlet or by using a rheostat to control it.

BTW an added bonus to properly adjusting combustion air is that the glass stays cleaner.

WNY wrote:Yes, already keeping an eye on it. Draft's Good! I think with the hotter burning temps, it is actually drawing a bit more. It's around .04-.05 with the baro at least 1/2 open.

I can't even get it down to .02 with the baro completely open by hand. That's how good the chimney draws.

Thanks!

The hotter the burn the more the chimney will draft. Hot air rises. The draft on the chimney will be very low with no fire in the appliance connected to it.
I've never checked the draft in the Alaska, I'll do that today. The pipe draft just before the baro is running around -.025" WC.

Matthaus wrote:

WNY wrote:Yes, already keeping an eye on it.

Just to make sure there is no confusion here, Dave I think coalstoves meant you need to check the static pressure in the stove, you can only check this by drilling a small hole in the stove body. I usually do this just below the door and above the ash door. Then you can leave it or drill/tap for a 1/8" pipe plug and reinstall each time you check. The actual pressure in the stove can be positive which is not a good thing. A minimum for stove static pressure would be -.02"WC and you can adjust this by covering the combustion fan inlet or by using a rheostat to control it.

It looks a little confusing.

There are three drafts, one is the air that is set by the blower and/or draft door. This is combustion air fed to the fire.

The second is the overfire draft, this is inside the unit above the coal fire. This is the draft mentioned in the above posts.

The third is the chimney itself which starts at the stovepipe after it has left the appliance. As we all know, this draft must be checked prior to the barometric damper as that breaks the chimney's draw and we only want to measure what is being pulled from the heating appliance.

I don't believe there is any chance of the overfire draft going positive unless there is a manual pipe damper in use. If one is used, do so only if there are no leaks or gasket issues. I use one and get a positive overfire draft in my boiler which would appear to me to increase its efficiency. Again, use caution and check everything over and over until you know exactly what is going on.

I would concurr with Matt on the rheostat, it will give you more control.

coaledsweat wrote:..I don't believe there is any chance of the overfire draft going positive unless there is a manual pipe damper in use.....

I agree with coaledsweat completely for hand fed units but am offering the following to slightly qualify that:

For a stoker the underfire is always positive because that is where the combustion fan is applying it's air and it is in a closed plenum with the resistance of the air holes in the grate and the coal/ash covering them. The overfire draft is the entire firebox, and I have seen that number go to zero or + .01" WC which on a stoker is a very bad deal considering the open path from the combustion area up through the hopper. Of course each stoker stove is different and this statement doesn't apply to all.

In my experience the Harman's are the one most prone to a positive pressure in the firebox, hence the number of units I have seen with rotted out hopper bottoms from fumes coming up through the coal.

In any event this is a good topic to delve into since most folks only concern themselves with the pipe and not the firebox. I'm sure WNY has already checked all of this and has the stove running exactly as it should.

Checked, the blower does seem to be blowing more than normal, I forgot i still had my rehostats, I put one on the blower, and tuned it down some, seemed a bit better now, it was burning pretty high up the grate due to the increased air flow...it is gradually moving down the grate a bit...Thanks all !

Hi Dave, this amount of heat from the small burner??? Can you imagine if both burners were run in 'blast furnace' mode??? Pretty amazing to get that amount of heat from about two cups of coal !!

Greg

NO, that was with both burners running, the small one light up quite a bit when I re-lit it and the larger one burning pretty good to keep up to the thermostat setpoint. All seems pretty good now.....with the rheostat slowing the new blower down a bit....

At least I know the stove can be cranked higher if needed. I try not to go over 450-500 when cranking or really cold.

So you had a full burn on the small burner.. how large was the fire on the large burner?? 75%? 90%?

Once you get a near-full enclosure bonnet on the Hyfire, I think you will be able to get several degrees more heat in the whole house with the same coal use as you have now..

It's nice to have heat in the computer room isn't it??

Greg

Say Hi ti Tammy, and give the cats a pat..

It's been very nice having heat everywhere, the stove in the garage heating the upstairs, last check on the Keystoker, I used 9 - 50#bags in 3 weeks.!! It mostly idles and keeps it 65 degrees.

Yes, Hyfire heat jacket and hot water loop for next winter's projects.

See ya Greg, Tammy & Cats say hi!