Harmon Stoker - Smoke out the back of the coal hopper

As I posted earlier tonight, I pulled my stoker apart to fix a jammed push block. Put it all back together and fired it up. Now I have white smoke coming out the bottom of the hopper - coming out between the pusher motor cover and the hopper where the hopper fits into the back of the stove. Now, I did put some oil in the bearings and spilled some, but this is nowhere near the motor - smells like sulfur. CO monitor hit 30 so I shut it down.

What did I do wrong?

Probably burning oil from the spill. Does it smell like rotten agss or burning oil?

coalkirk wrote:Probably burning oil from the spill. Does it smell like rotten agss or burning oil?

Smells like rotten eggs - sulfur. My first thought was oil because it was visible white smoke, but when the CO monitor hit 30 on the first floor - the stove is in the basement - I got worried.

if you pulled the stoker assembly off the back of the stove I would guess it is not seated correctly on the gasket when re-assembled.

I didn't pull the assembly off the stove - I pulled the block out through the front of the stove, but I guess it still could have gotten moved. It seems to be coming out around the base of the hopper where it fits into the stoker unit.

did the baffle on the combustion fan get moved so that its more wide open than previously?

titleist1 wrote:did the baffle on the combustion fan get moved so that its more wide open than previously?

Looks to be about the same....I'll double check. Nope hasn't moved.

did some of that pasty stuff clog the holes in the grates? is the fire burning further back on the grates than previously? obviously the combustion air/exhaust is finding it easier to exit through the coal feed path rather than the exhaust port.

I did have to loosen the brace that holds the top of the hopper to get it off. Is there any adjustment in that brace?

if you mean that bracket with a lip that catches the top of the hopper, then no that should not have an effect on exhaust coming out the bottom where the hopper feeds the coal to the stove. You must have had the grate holder off to get the pusher block out, is it seated properly at the back and sitting flat on the stoker assembly?

titleist1 wrote:did some of that pasty stuff clog the holes in the grates? is the fire burning further back on the grates than previously? obviously the combustion air/exhaust is finding it easier to exit through the coal feed path rather than the exhaust port.

I made sure the grates were clean and the space under the grates was clean too. I vacuumed the horizontal section of the pipe to the chimney (pipe is new).

also there should be a gasket between the grate holder and stoker assembly that it sits on, maybe that gasket is not sitting as it should.

titleist1 wrote:if you mean that bracket with a lip that catches the top of the hopper, then no that should not have an effect on exhaust coming out the bottom where the hopper feeds the coal to the stove. You must have had the grate holder off to get the pusher block out, is it seated properly at the back and sitting flat on the stoker assembly?

I did not take the grate holder off. I unscrewed the threaded rod from the back of the push block. I was able to push the block over the grate holder without removing it.

how far back the grates was the fire burning? was it headed into the hopper? it doesn't sound like you moved anything that would change the combustion air flow path so the only thing i can think of is that you don't have it feeding new coal fast enough and the fire burns too far back the grates. how many dots are you pushing?

by the way, what draft is your flue pipe seeing and can you take a manometer reading on the firebox?

titleist1 wrote:how far back the grates was the fire burning? was it headed into the hopper? it doesn't sound like you moved anything that would change the combustion air flow path so the only thing i can think of is that you don't have it feeding new coal fast enough and the fire burns too far back the grates. how many dots are you pushing?

by the way, what draft is your flue pipe seeing and can you take a manometer reading on the firebox?

I was pushing 3 dots. Fire was close to the front of the stove like 2" from the front...but it may have gone close to the back. It was hard to get it started, but then it really took off. I don't have a manometer and don't know what my draft was, but the barometric was open - the chimney liner is 51/2 inches. It usually has a good draw.