Help with my Biomass boiler - Tarm HS 4.0

I am running my Tarm HS 4.0 for the first year this year. It heats extremely well. Running roughly 3k square feet. 5 zone system with 1 radiant floor heat zone. The rest are old cast iron radiators. It is a new install. Mostly copper from the boiler to the header system, and pex from there to the radiators. The radiant floor heat is running with a mixing valve.

I am plowing through about 1 ton of fuel a week...be it corn or pellets. To me that is an insanely high consumption rate....

I have propane forced air backup. It heats just fine. I'd run that 100% but really wanted this biomass to work.

Few observations, FWIW:
1.) metering valves are on the output side of the registers
2.) Radiant floor heat does not work well. That room will not get above 55 degrees. Its pex only with no other heat transfer mechanism in line.
3.) Burning corn might be the issue right now because of moisture content - it makes big clinkers and hurts the efficiency a bit because of it.
4.) Its running a flue dampener - Tarm called for it

Any suggestions? I can't afford $800 to $1000 per month in fuel. I'd be better off pulling it and putting a propane boiler in. I also have a Harman Accentra insert for the addition room (one with radiant floor heat) - it's just not installed yet.

Is there anything obvious I need to check? Any help or suggestions would be appreciated.

Video attached of the boiler. I'll dig up pics of the manifold as well

Correction - 1 ton a week.

Radiant floor heat is about 110F. Ive tried adjusting the mixing valve but it hasn't changed.

Pellets burn just about as fast as corn...corn is a bit cheaper however.

Going to go back to mixing corn/pellets together. Seems like a good combo. Doesn't produce much of a clinker issue.

This unit will burn anything. I guess I need to start collecting cow patties and mashing them up in the hopper lol...

Chris Hoskin said:

Nice looking set up, turbulator. I noticed that the boiler temp was showing only 40C and I did not see a Termovar mixing valve in the system. Had you just started the boiler? Do you have the mixing valve?

Lots of uninsulated pipe there - where does it go once it goes through the slab?

My parents ran a MH 4.0 for a few years and went through about 12 tons of bagged pellets a year to heat their old farm house. We used to burn about 20-ton per year here at the Tarm Biomass warehouse when we were heating it with a 4.0. My point is that boiler can put out a lot of heat and, when asking for it, will use a lot of fuel. That being said with "only" 3000 square feet, your fuel consumption is high. All that heat has to be going somewhere....

Are you heating a concrete slab from dead cold? Long run of uninsulated pipe between the pellet boiler and the distribution manifold? What are you seeing for stack temps? Does the boiler ever cycle into low or pilot, or is it running flat out all the time?

Tom is right, you will need higher temps in the staple up to heat that room.

looking forward to hearing more.

Chris

Click to expand...

Thanks Chris. The manifold system is about 20' away, it runs under a crawl space. The lines are uninsulated. What would you recommend to insulate them? The crawl space isn't "cold" but I have no issue putting some insulation on them.

There is a mixing valve for the radiant floor heat. I just adjusted it when I raised the water temp in the boiler to 85c. It's now about 140F.
Correct that video was shot at first fire up, so the water temp on the display is sort of irrelevant.

I'll try insulating the main lines to the manifold and see if that helps, also the lines in the boiler room itself.

As far as heat loss in the house. It is an 1800's house but was fully remodeled 20 years ago.. New insulation, all new Certainteed vinyl replacement windows. They are floor-to-ceiling windows however. I'd imagine there is some loss going on with them...but again when running the propane forced air, I don't use that much fuel really.

I guess I could supplement the system and run the propane and the boiler....but the boiler heats the room to 73-74 degrees even when the thermo is at 68 due to the amount of water lines in the basement feeding the registers. Pretty much every register has its own feed from the manifold and metering valves...thought about adjusting those a little to see if it helps.

Here are some pics of the manifold and registers, and a pic of the house before the yard was put in. We built the garage and breezeway last winter and also re-sided/roofed the place.