EFM - Efficiency

I just retired my stoker stove and bought a refurbished EFM 520. I understand that there are a lot of factors that play into how efficient the unit runs like how well you home is insulated, the temperature outside, type of coal, how much square footage you are heating, etc. I am interested to find out from long time users of EFM boilers what they have found out through trial and error, the most efficient settings are. My example would be, just turning the feed rate down to a 2 or 3 may not necessarily use up less coal because it has to run more just to keep the boiler at temperature. I don't know if that is a good example but I am just throwing it out there trying to let everyone know what kind of feedback I am looking for. I know there is a thread already that talks about some of this but I guess I am trying to get my mindset thinking correctly about boiler temperature, feed rate, air adjustments, etc. I have a ranch home with a semi finished basement.
I am not in the basement much so I keep the therm down to about 54 to 58. The boiler itself is in a enclosed furnace room in the basement with a door that I leave open. My main level is approx. 1400 -1600 square feet. The last couple days since the temperature has been in the 20's and 30's I have been going through almost 2 - 5 gallon buckets a day which seems high to me. Any feedback, suggesions, information you can share would be greatly appreciated.
Thank you!

That seems high to me too.

Any central heating system also has losses in uninsulated piping and losses to the basement from the boiler. Turn down the basement thermostat as low as it will go. I believe you are heating much more than your upstairs.

The basement radiators feel cool. I will turn the thermostat down all the way to be safe.
Thank you.

A few questions to help figure out what's happening:

1. Was the unit installed with a barometric damper and a hanging baffle in the combustion chamber area?

2. Are the gaskets good (and the fit tight) on the ash and fire doors?

3. Have the spaces between the base plates and the base been sealed? How about the visible part of the "channel" where the boiler head is sitting in the base?

4. Is there insulation on the boiler head?

5. When the stoker has been running for at least 30 minutes, is the ring of ash around the outside between 1-2" wide? You don't want to have either hot coals going over the edge or an excessively wide ring of ash - need to adjust feed and air settings to achieve this.

6. Are you making DHW with btu's from the boiler?

7. Where did the coal come from?

8. What are the timer settings?

Mike

1. Was the unit installed with a barometric damper and a hanging baffle in the combustion chamber area? - No to barometric, yes to baffle.

2. Are the gaskets good (and the fit tight) on the ash and fire doors? - Brand new, tight gaskets

3. Have the spaces between the base plates and the base been sealed? How about the visible part of the "channel" where the boiler head is sitting in the base? - Boiler sealed around base. Not sure about spaces between base plates.

4. Is there insulation on the boiler head? - No insulation or cover on boiler. Plain steel exposed

5. When the stoker has been running for at least 30 minutes, is the ring of ash around the outside between 1-2" wide? You don't want to have either hot coals going over the edge or an excessively wide ring of ash - need to adjust feed and air settings to achieve this. - The ash ring is 2 to 3 inches.

6. Are you making DHW with btu's from the boiler? - Yes unit is used for DHW. 2 adults and one teenager.

7. Where did the coal come from? Hazleton are - supposedly around 400 feet down not strip.

8. What are the timer settings? - Timer is set to run for 3 minutes every 1 1/2 hours.

Thank you

I'm pretty sure the manual says it should have a barometric damper. Without it too much heat goes up the chimney.

Sealing the panels to the base couldn't hurt.

If there is no insulation on the boiler head it will function as a big radiator that is always giving off heat. It adds comfort but uses some coal to do it.

I would increase the feed a bit to make the ash ring a little smaller.

Making DHW for 3 people and heating the house with no baro, no boiler insulation and a slightly oversized ash ring seems like it goes along with the coal use you described. With a baro, tuning the ash ring and maybe putting a blanket of foil-faced insulation on the boiler head your usage should go down.

Mike

Seal up the base. The only air going into the combustion area should come through the blower housing. Of course as you tighten the base up, the draft becomes more critical. Install a Baro, otherwise you are wasting coal and could have outfires on windy days.

What feed/air and aquastat settings are you running?

I appreciate all the help.

I am currently running a 4 feed and a 4 air.

My high is set at 180/low 150 and the differential is 15.

4/4 is a common setting for your stoker, but a little more or less air is sometimes needed to accommodate different coal sizing/characteristics. Like Mike explained, it is best to judge the ash ring after a steady 30 minute burn. As for the heat load, do not underestimate the amount of coal required to produce domestic hot water...especially when a teenager is involved. Your stoker stove never had to power a 20 minute shower, or heat the house from corner to corner with an 80 degree boiler room.

The last time I installed an Efm I used foil face hard foam board insulation. I cut the pieces out to fit around the pipe fittings and door on the boiler, and sealed the seams with foil tape. I was very impressed with how well it held the heat in the boiler.

Beat me to it Rob!!!!!

I wonder where I got the idea for the foil-faced foam?

Thanks for posting the pictures, I didn't take any when I insulated mine.

Thank you both for the information and pictures. I actually have a couple pieces of the foil insulation laying around from another project. I will give that a whirl. I'm a little confused about how to seal off the base. I have the base on blocks on the four corners similar to the pictures but not as high.

OH, by the way. I was talking to an 'old timer' plumber the other day. He asked a strange question to me, at least I thought it was strange. He said years ago there used to be a debate on which way was best for your outlets and returns. He asked me which way mine were set up. I told him as per EFM's manual with the circulator pumps mounted in the back on the return line pumping into the boiler and the outlet being at the top. Is that how you all have or had yours set up?

AKHEARTH wrote:OH, by the way. I was talking to an 'old timer' plumber the other day. He asked a strange question to me, at least I thought it was strange. He said years ago there used to be a debate on which way was best for your outlets and returns. He asked me which way mine were set up. I told him as per EFM's manual with the circulator pumps mounted in the back on the return line pumping into the boiler and the outlet being at the top. Is that how you all have or had yours set up?

You can do it either way. New school of thought says to put them on supply as not to pressurize boiler. Second school of thought seems to think there are a bazillion all ready mounted on the return. What I can tell you, they don't work so well if they are in the highest point in your system.

Good evening. Should the return always be in the back of the boiler? A guy I work with told me his return is coming in the top of the boiler. I don't think that is correct is it?
TY