Keeping coal burning all day and night.

I have a New Yorker WC 130 multi fuel boiler that was in the house when I bought it last fall. I burned wood all last winter mainly because there was 6 cords of wood in the basement when house was bought. This winter trying coal. I have an old two story house roughly about 2200 sq ft. Thermostats on each floor, (two zones).
The issue is when both zones are satisfied and nothing is calling for heat the coal burns out over time unless I mess with it like open the ash door or turn the thermostat up to get the blower to turn on. The coal stays hotter than wood and longer which keeps the boiler at the set temp for such a long time that the blower does not turn on enough ti give the coal the air needed. At least that’s what I think. I have adjusted the aqua-stat from 160 to 170 and even 180 degrees to see if that makes a difference and doesn’t seem to. Overheat set at 200 degrees. The house is not insulated that well and this is when temps are between 10 to 20 degrees. It does have a barometric damper on the flue.
Not sure what else to do. Any help would be greatly appreciated!

Good Morning Nor'easter,I know little about boilers ,and my comment will probably prove that,but could you somehow create a small,probably very small,opening below the fire that would let a very limited amount of air to always be fed to the fire therefore keeping it alive ?Or is this a no-no.

Thanks for the response. I have wondered the same thing and am looking into it to see what I can do. I am going to look at the blower to see if there is a flap or something that blocks the air flow when it’s not on. Might be a way to alter that to let some air in. Does coal require constant air from underneath the bed? I wasn’t even sure about that. I believe from the damper and the air shutter in the door it has constant air over the top. Still learning how coal burns. Very new to burning coal. I believe my bed depth is deep enough so assuming it’s something else. Yesterday in one filling it burned or about 10 hours. Then before bed I shaked it and added a little more fresh coal and made sure it was burning good before going to bed. Then in the morning the coals wet completely out. It is a multi fuel boiler so may not be the best design for coal.

Coniglio wrote: ↑

Sun. Dec. 19, 2021 9:55 am

small,opening below the fire that would let a very limited amount of air to always be fed to the fire therefore keeping it alive ?

The WC-130 should have a sliding damper over the fan opening, at least the WC-90 does. There is a spec for the distance that it should be set open so that some air can flow to keep the fire alive when there is no heat call. Not that I have the answer to your issue but the setting of that damper will be part of the question to deducing the problem. If it is too small I would suspect that not enough air is getting to the fire. Quality of draft will be another question to determine, the fan may over come the lack of draft but there is not enough to maintain the fire. Ash blocked flue maybe?

link to manual for New Yorker WC-90/130

Scroll to page 12 for the damper settings.

Yes coal requires bottom air to burn, back your top air damper down and set the fan damper to spec and see what happens.

Appreciate the info. I have read the manual multiple times, ha ha. I have tried the setting recommended in the manual and I have tried having the shutter on the blower wide open and still the same results. I think the issue with the blower might be that it shuts air off completely when not it’s not running. When the boiler is to temp it shuts the fan off and circulates the heat until the temp drops then turns the fan back on. I’ll need to look into that to figure out what’s going on there.
Also, I am thinking my depth may not be deep enough and the ash build up this morning was a lot. That in combination with the air flow is probably the reasons it’s going out.

Thanks BunkerdCaddis. I will try to back the top air down as well.

On further investigation the blower does not shut air flow off when it turns off. So the coal is getting some air flow even when the blower is not running. I will try again and set at the recommended setting. I am going to try and damper down the over the top air flow as well.

Nor’easter wrote: ↑

Sun. Dec. 19, 2021 11:23 am

Also, I am thinking my depth may not be deep enough and the ash build up this morning was a lot. That in combination with the air flow is probably the reasons it’s going out.

Very possible, coal likes a deep bed with air from below. Wood fire is like a frat party, it likes to run wide open. Coal fire is like a group of deep thinkers who like to huddle around talking quietly amounst themselves. It's one of the big changes from burning wood that takes some time to wrap your head around. Fill it up with coal to the level that it has on the label, keep the ash knocked down to a point where it it just protects the grates, you will learn how much ash you can tolerate before it chokes the fire. I use ash to my advantage to close off the sides of my firebox in warmer weather to keep a small fire deeper.

BunkerdCaddis wrote: ↑

Sun. Dec. 19, 2021 12:11 pm

Very possible, coal likes a deep bed with air from below. Wood fire is like a frat party, it likes to run wide open. Coal fire is like a group of deep thinkers who like to huddle around talking quietly amounst themselves. It's one of the big changes from burning wood that takes some time to wrap your head around. Fill it up with coal to the level that it has on the label, keep the ash knocked down to a point where it it just protects the grates, you will learn how much ash you can tolerate before it chokes the fire. I use ash to my advantage to close off the sides of my firebox in warmer weather to keep a small fire deeper.

The line it says to fill the coal up to would only make it about 6 inches deep, is that enough? I had it at about 7 inches last night. I have a read a lot of people say 8 or 9 inches deep. Also, the edges/corners of the fire box have angled bricks. So the coal that sets on the edges probably isn’t getting much air, if any. I think I need to put firebrick in the sides so the coal is only over the grates and just fill it deeper. And yes I need to figure the ash part out.

You could go higher than 6, I was thinking it was closer to 8 inches but heap it up in the center more so. Member Hotblast had a good thread here > New Yorker WC 90 on his WC-90. My son has our WC-90 set up in an outdoor shed (it's not the best setup but it's kinda short term).

There should be cast iron plates in the lower corners that are angled you shouldn't have to modify that at all it should work fine. As we are chatting I'm thinking it's just the learning curve in the change to coal from wood that's the issue here but do check your flue for any clogging from creosote, the new yorkers are creosote monsters on wood so that is a possibility also. So to summarize... clean chimney/flue, deep bed/light layer of ash and good bottom air supply makes a happy heater.

Thank you! I did just have my chimney cleaned a few weeks ago. The guy said it was pretty dry and no creosote buildup. I know there is a learning curve. Just have to figure it out I guess.thanks again.

Nor’easter wrote: ↑

Sun. Dec. 19, 2021 12:38 pm

The line it says to fill the coal up to would only make it about 6 inches deep, is that enough? I had it at about 7 inches last night. I have a read a lot of people say 8 or 9 inches deep. Also, the edges/corners of the fire box have angled bricks. So the coal that sets on the edges probably isn’t getting much air, if any. I think I need to put firebrick in the sides so the coal is only over the grates and just fill it deeper. And yes I need to figure the ash part out.

Fill it up as far as you safely can. I burn a hand fired stove and I bank my coal up far above the pot.

BunkerdCaddis wrote: ↑

Sun. Dec. 19, 2021 1:25 pm

There should be cast iron plates in the lower corners that are angled you shouldn't have to modify that at all it should work fine. As we are chatting I'm thinking it's just the learning curve in the change to coal from wood that's the issue here but do check your flue for any clogging from creosote, the new yorkers are creosote monsters on wood so that is a possibility also. So to summarize... clean chimney/flue, deep bed/light layer of ash and good bottom air supply makes a happy heater.

There are angles cast iron plates. I guess I shouldn’t have bought $100 of firebricks today then….

My stove has manual controls and I know little about other stove configs but I think the process of adding coal is about the same in all stoves.I agree 100 % with Bunkerd Caddis-Keep your coal level as deep as you can.To the top of the bricks at least.Also,do not add small amounts of coal at a time.Wait until your previous load of coal is mostly burned up and then shake till you get a bright ,red glow on the top of your ash in the ash pan and add your next batch of coal in 3 or 4 applications giving it enough air to have it catch well each time before adding more.Be sure to shake out enough ash to get a GOOD draft.You should be able to hear the air being drawn in and sparks and bits of ash and dust should fly up from the fire,Do not completely cover the existing bed each time but leave space between the pieces of coal to let air through.Give the first application air and give it 5 minutes of so to catch well,then add more.Build the pile of coal up higher in the back of the stove than in the front.Coal seems to like to burn uphill.When full give it air for a few minutes,possibly up to 15 minutes or so to get going well and then close down the draft air in increments until you get the draft set how you want it.As B.K. said there is definitely a learning curve to transition from wood to coal.You should get 12 hours at least between fillings. More or less forget all you know about burning wood and start off fresh learning about coal.---Frank