Clinkers!!!

kstills · Post by **kstills** » Thu. Nov. 20, 2014 7:28 am

Ok, a recurring problem, but one I'm determined to solve.

Bought coal in October, and it burned fine under the low demand for heat and DHW up until this cold snap. Now with the house calling for sustained burns out of the boiler, I'm getting clinker build up on the front of the grate which pushes the fire back towards the hopper and making it 'lazy', ie the flame does not reach the diffuser, recovery times suck, and on really cold nights I see a drop in the household temperature.

I can break up the clinkers and the boiler starts firing properly right away, but only until the ash fuses again and backs up the burn area.

Two things I'm going to try:

Decrease the draft over the flame. Currently running 1.5, I'm going to drop that down some. I don't particularly like this option, however when it's cold I'm pulling a pretty strong draft out the chimney.

Decrease the fan CFM. The new fan has that plate that allows for modification in the amount of underfed air to the grate, I'm hoping that by decreasing the air flow I decrease the temperature of the coal on the grate and can hit the sweet spot where I'm getting enough BTU to heat the house but not enough to fuse the ash.

Flyer5 · Post by **Flyer5** » Sat. Nov. 22, 2014 1:13 am

How low is the rheostat for comb set at idle. Too little air could also cause clinkers. Also if you cleaned under the grate make sure it is completely seated. That may be more likely. Dave

kstills · Post by **kstills** » Wed. Dec. 03, 2014 3:58 pm

Flyer5 wrote:How low is the rheostat for comb set at idle. Too little air could also cause clinkers. Also if you cleaned under the grate make sure it is completely seated. That may be more likely. Dave

Too little idle air could cause clinkers? That's something I hadn't thought about, but to be honest, this is the same coal I burned during October when it mostly went for hot water usage, meaning that it idled longer then it went into a full burn. I wasn't seeing clinkers then.

I do have the fan adjustment closed somewhat, I'll open that back up and see if it makes a difference.

I really think it's the coal, 2 years out of four I've not had a problem, the other 2 it's a constant battle with this crap.

Oh, well, it's still better then oil!

Post by **Rob R.** » Wed. Dec. 03, 2014 4:50 pm

Try reducing the combustion air.

Post by **Lightning** » Wed. Dec. 03, 2014 5:50 pm

kstills wrote:I really think it's the coal, 2 years out of four I've not had a problem, the other 2 it's a constant battle with this crap.

Perhaps you could try a couple bags of something else to see if it performs better. Are you using red ash coal? It tends to clinker easier than white ash coal..

kstills · Post by **kstills** » Tue. Jan. 06, 2015 10:42 am

I wanted to come back to this thread, as the issue has been (hopefully) resolved.

The new fan that LL had sent last year is adjustable, which is probably a bad thing to give a guy who likes to play around with variables. So I had got it in my head that my draft was better with less air flow through the grate, and was running it that way most of the summer.

Come colder weather, I suppose that wasn't the optimum setting, because when Dave suggested more air through the grate I opened it up all the way, and haven't had the same clinker issue that I had at the beginning of the season. I still get some smallish clinkers, but I no longer get a log jam in on the grate that kills the recovery time of the boiler because the fire becomes so low that it barely heats the water in the tank.

So, thanks Dave!

Flyer5 · Post by **Flyer5** » Tue. Jan. 06, 2015 11:31 am

kstills wrote:I wanted to come back to this thread, as the issue has been (hopefully) resolved.

The new fan that LL had sent last year is adjustable, which is probably a bad thing to give a guy who likes to play around with variables. So I had got it in my head that my draft was better with less air flow through the grate, and was running it that way most of the summer.

Come colder weather, I suppose that wasn't the optimum setting, because when Dave suggested more air through the grate I opened it up all the way, and haven't had the same clinker issue that I had at the beginning of the season. I still get some smallish clinkers, but I no longer get a log jam in on the grate that kills the recovery time of the boiler because the fire becomes so low that it barely heats the water in the tank.

So, thanks Dave!

I am from Leisure Line and I am here to help.