Coal Usage and Timers

I,m using to much coal in my Van wert stoker set up in a National 4 section cast boiler. I have it all set with a single aquastat set on 180 deg. That has me stuck at high limit for the burn, the dif is set for 15 deg. I recently did a lot of insulation to my house and I still use the same amount of coal, (55 gal/day).
I have 5 zones in the house and garage using separate pumps and flow controls for each. I'm thinking I need to set it up so that the stoker only burns when a pump is running and not to maintain a set boiler temp, with a timer to keep the fire burning. Is this right? What controls do I need? Where do I get them? Part #'s would help. I'm heating 2206sf.

Some pix of your set-up would be real helpful.

Is this a conversion stoker?

What is the stack temperature?

It is a conversion and works great, with no fire out cases even when it gets warm out, but uses to much coal because it is always burning to maintain boiler temp. In warmer weather I do turn the temp down. I've seen it not run for 8 hrs at time and still be burning, but it does run while my house is not calling for heat.

WHOA...55 gallons of coal is 400 pounds per day.

PatT15 wrote:II'm thinking I need to set it up so that the stoker only burns when a pump is running and not to maintain a set boiler temp, with a timer to keep the fire burning. Is this right?.

as long as the vessel doesn't drop below condensing temperatures - but chucking that much black rock - I doubt it ever idle fires

Like I said, in warmer temps when I turn it down to say 135, it will go almost all day and not run. Thats what makes me think I need to control it differently.

You need to figure out where all the heat is going. 400 lbs per day is NUTS for a 2200 sq. ft house in this weather.

Keeping the boiler at 180 all the time is not ideal, but it doesn't account for the amount of coal you are burning compared to most homes of that size.

What kind of feed rate is the stoker running?
Have you adjusted the air to optimize the fire?
Draft?
Stack temperature?
Where is the boiler located?
Is the boiler insulated?

Like I said earlier--some pix would really help--of course so would fillin out your profile--might be someone close that could really help--Really, nobody's gonna steal ya.

The feed is not adjustable and is set at 18lbs per hr and the air is set good with almost no unburned coal in the ash. The draft is good with a baro and while the stack temp is hot I have not checked the actual temp. The boiler is in my basement and is well insulated with a metal jacket covering it. It is burning well with no over fire pressure.

freetown fred wrote:Like I said earlier--some pix would really help--of course so would fillin out your profile--might be someone close that could really help--Really, nobody's gonna steal ya.

I don't have the capabilities to put pics up right now so sorry, and I'm in Morrisdale pa. (central pa. near state college). I'll have to get after that profile.
I believe that this is a controls problem cause my oil furnace is the same way, burning a tank a month.

I'll leave the controls issues to those who have more expertise.

With a conversion stoker you might want to take a close look at the integrity of the seal where the stoker enters the boiler. If your draft is pulling room air into the combustion chamber, that could waste a lot of btu's. Similarly, it probably would be good to check the seal between the boiler and the floor, between the cast iron sections, around the fire door, etc.

The air should be set to produce about a 2" ash ring around the fire after a long (30-45 minute) burn. The presence of some amount of unburned coal is normal, and it is inefficient to supply excess air to try to get rid of it (blows cooling air through dead ash into combustion chamber).

Do you clean the heat exchange surfaces regularly?

Mike

Gottcha--good on your location, hopefully some knowledgeable person is close by--words are great but ya can't beat the final touches with a visual hands on

PatT15 wrote: I have it all set with a single aquastat set on 180 deg.

I think you need a triple aquastat or additional singles and some logic to simulate a triple. I think that would significantly help your case. When the house is not calling for heat the boiler should be let to idle down to say 160 or so unless there is another call for heat. Then have your high set to 180 or to your desired radiation temp. It sounds like your manually adjusting your temperature of the boiler based on outdoor temps. Typically they are let to idle lower then desired output during a call for heat.

PatT15 wrote: I have it all set with a single aquastat set on 180 deg.

Good for you - that's the start of good controls on a solid fuel appliance

Mikeeg02 wrote: I think you need a triple aquastat

Worst advice ever - these are cheep alternatives to correct operation - installed by manufactures to cover all applications - best used on oil or gas appliances

Mikeeg02 wrote: or additional singles

well now your smoking
but suggest an Outdoor Reset to control boiler temperature in relationship to the degree day load on the dwelling

Kind Regards
Sting