Biomass 80 "HEAT" shutdown

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jaoneill

Feeling the Heat
It certainly isn't a "life or death" issue but my worst fears have come to pass with the controller's "HEAT" shutdown. Our oil boiler is tied into the primary loop and takes over when the Biomass shuts down, so it's not like we have no heat, however, I feel we are feeding big oil unnecessarily.

It has been -10 to -25 here most nights for the past few weeks with enough wind that the heat load is pushing the max. Problem is that more times than I care to think about this winter (usually in the middle of the night) the load is heavy enough that the "80" struggles to keep up, the controller assumes that the wood has been devoured and shuts it down. I go down to feed the fire at 6:00 AM only to find the dreaded "HEAT" staring at me while the upper chamber is 1/2-3/4 full of charcoled wood, and the oil boiler is humming away, which it has probably been doing since 2:00 AM.

I usually fill for the night at about 9:00 PM and, if temps are -5 or higher, the "80" is still up to temp, cooking away at 6:00 AM. I feed it and get on with the day. It is most annoying that when we need it most the damn thing craps out. I would love to know how to disable the "HEAT" mode, or stretch the timing out another 2 hours (I have it maxed at 4 hrs).

Any suggestions?

Jim
 
What controller do you have on your Biomass? I'm not familiar with a "HEAT" error and thought you guys had the same controller as the EKO. If you believe it's shutting down due to a timeout for wood/fuel load you should check to see if you're getting any bridging (search for this term).

For whatever it's worth your Biomass 80 should not be struggling to keep up in any conditions unless you're heating an airplane hanger with the door open. That is a beast of a boiler. If it appears to be struggling I'm betting it's sub par wood, plumbing problems, air in the system, draft issues...or all four?
 
What controller do you have on your Biomass? I'm not familiar with a "HEAT" error and thought you guys had the same controller as the EKO. If you believe it's shutting down due to a timeout for wood/fuel load you should check to see if you're getting any bridging (search for this term).

For whatever it's worth your Biomass 80 should not be struggling to keep up in any conditions unless you're heating an airplane hanger with the door open. That is a beast of a boiler. If it appears to be struggling I'm betting it's sub par wood, plumbing problems, air in the system, draft issues...or all four?

Controller is an RK2001UA-D.

Wood is not ideal but not terrible either. It is standing 5-7 year dead elm at 14%-17% moisture when it went into the woodshed in July, last I checked, a week or so ago when I was re-splitting it was +/- 12%. I was having continuous problems with "blow holes" until I turned the blower down to 70%. Started having issues with bridging when it got really cold so I turned it up to 80%. I have been re-splitting down to splinters (no more than 2 1/2" to 3") to stack over the nozzle and like I said above, it has been fine until temps get down to a windy twenty below or colder. Bridging, leading to those damn blow holes, is the issue, but if it would just keep firing, gasification or no, it might keep up.

The other thing I haven't determined the cause of is that the wood burns faster toward the rear, leading to a blow hole at the rear nozzle while there is still a 1/2 stack toward the front. I clean out the primary air supplies regularly and they occasionally will be partially plugged toward the front, but never completely blocked, and I hit the openings with the poker at least twice a day to make sure they are clear. Don't doubt I'll figure it out eventually but it is puzzling.

I pretty much understand what the issues are, but there doesn't appear to be a lot I can do about it until next year when I will have a better wood supply.

House is big, 17 rooms, 10' ceilings, forty something 3'x7' windows, six 3'x7' exterior doors. We have 75% of the second floor closed off and are in the process of rearranging the living space on the first floor so that we can close off at least 600-800 sq ft of that. System is primary/secondary with nine zones, 320K of cast iron radiation at 180 degrees. Currently utilizing 5 zones, plus the DWH set on priority. When all five of these circs are spinning at the same time, which they have been, the load is around 200K, which doesn't leave an abundance of capacity unless the 80 is firing at optimum.
 
JA, Do you mean the "FUEL" sign? Could be wood moisture content which makes bridging/blow holes more frequent. I'm having to mix some of my 1 year seasoned wood with my 2 year stuff and seeing an increase of the event you describe. New coals are not replenishing the old fast enough resulting in a nozzle opening which leads to not hitting the set point triggering "FUEL" and shutdown. It thinks the fire is dead. When I'm having this problem I stack against one side instead of filling against bith sides. This reduces the likelihood of bridging somewhat as the wood is less likely to keystone forming a bridge. For me the best defense is to make sure my most seasoned wood is on the bottom and the boiler's good and hot before I bid it good nite. I also sometimes go to a lower set point (190-192F) which is easier for the less than ideal wood to sustain.

Also, don't let too much ash accumulate in the bottom of the upper chamber. Lots of fine ash chokes air from feeding the new coals. A healthy coal bed supports air feeding the new coals. Clean the ash from the upper chamber down to the ceramic and see if that helps. It is frustrating but less frequent with hot fires and dry wood. Also will be more frequent if idling a lot without storage. Best wishes.
 
I just read your last. I can blow out my gasification flame with too much fan. You may want to experiment with your nozzle opening. Too much fan can create blow holes. I don't know why but for years I was afraid to watch my gasification flame with the lower door open to see the size and how energetic it was. Right now I get best gasification at 60% fan. I go 80 or 90 and it's counterproductive. Watch the flame with the lower door open and learn the effect of fan speed.

Also in general it seems most BioMass's ship with the vents too closed. If you've never experimented with the primary and secondary vents, you may want to open them and watch the flame in the lower chamber for effect.
 
I just read your last. I can blow out my gasification flame with too much fan. You may want to experiment with your nozzle opening. Too much fan can create blow holes. I don't know why but for years I was afraid to watch my gasification flame with the lower door open to see the size and how energetic it was. Right now I get best gasification at 60% fan. I go 80 or 90 and it's counterproductive. Watch the flame with the lower door open and learn the effect of fan speed.

Also in general it seems most BioMass's ship with the vents too closed. If you've never experimented with the primary and secondary vents, you may want to open them and watch the flame in the lower chamber for effect.
 
JA, Do you mean the "FUEL" sign? Could be wood moisture content which makes bridging/blow holes more frequent. I'm having to mix some of my 1 year seasoned wood with my 2 year stuff and seeing an increase of the event you describe. New coals are not replenishing the old fast enough resulting in a nozzle opening which leads to not hitting the set point triggering "FUEL" and shutdown. It thinks the fire is dead. When I'm having this problem I stack against one side instead of filling against bith sides. This reduces the likelihood of bridging somewhat as the wood is less likely to keystone forming a bridge. For me the best defense is to make sure my most seasoned wood is on the bottom and the boiler's good and hot before I bid it good nite. I also sometimes go to a lower set point (190-192F) which is easier for the less than ideal wood to sustain.

Also, don't let too much ash accumulate in the bottom of the upper chamber. Lots of fine ash chokes air from feeding the new coals. A healthy coal bed supports air feeding the new coals. Clean the ash from the upper chamber down to the ceramic and see if that helps. It is frustrating but less frequent with hot fires and dry wood. Also will be more frequent if idling a lot without storage. Best wishes.

I'll try stacking against one side. What is your normal set point? I have mine set at 185; should I increase it?

On your advice from a couple of months ago, I have been religious about keeping the slanted ceramics clear of ash. I have an old coal furnace poker with a 5" leg that I sweep the slants with at every fill, that has made a substantial difference. It has been cold enough it hasn't done a lot of idling.

Thanks for the reply, Jim
 
I just read your last. I can blow out my gasification flame with too much fan. You may want to experiment with your nozzle opening. Too much fan can create blow holes. I don't know why but for years I was afraid to watch my gasification flame with the lower door open to see the size and how energetic it was. Right now I get best gasification at 60% fan. I go 80 or 90 and it's counterproductive. Watch the flame with the lower door open and learn the effect of fan speed.

Also in general it seems most BioMass's ship with the vents too closed. If you've never experimented with the primary and secondary vents, you may want to open them and watch the flame in the lower chamber for effect.

Again, on your earlier advice I had turned the air down to 70% with good results. I only recently stepped it back up to 80% when it got really cold, I'll step it down again. I have both primary and secondary vents open almost to the max and have had good results.
 
If your boiler has the RK-2001UA controller, which I thought Biomass boilers were equipped with, you can set the Fuel Out sensor from the default of 2 hours to 4 hours. This will allow more time for the boiler to get up to temp before going into "FUEL" mode and shutting down. Even if you have a different controller, it probably has a similar option. Also, it's important to reset the controller every time you add wood so that it starts the FUEL timer starts from scratch. Apologies if you're already aware of all this.
 
Steve, excellent suggestion on resetting the timer. Do you use Start-Stop buttons to do that? Usually I add to the fire right before bed but never thot to reset the timer.
 
One thing I noticed a couple days ago when we had wind for 2.5 days was that I had bridging which I attributed to increased draft. This was 4 year old wood stacked in a woodshed. I know you have induced draft vs my forced draft but blow holes would indicate to me that your draft should be cut back meaning you should cut back on the fan speed.
 
You can use the stop/start buttons or simply flip the switch on and off. The switch approach is probably better, because with that controller, it's a bit more difficult to see when it's in "stop" mode. If the boiler happens to be idling when you load it, you could forget to hit "start" again and walk away without turning it back on. Flipping the switch on and off is a foolproof approach. And, stop calling me Steve.
 
Thanks for all of the replies.....

Tennman - I dropped back to 70% after our earlier exchange. I don't see the bright orange glow through the sight glass in the lower chamber like I did with the higher setting, but it sounds as it should (hollow roar), and is holding temperature; it's currently -5 and windy here. No blow holes but it's only been a couple of hours.

Eric - I have it set at 4 hours and do the "turn-off - turn-on routine when I load for the night. Problem is I'm an early to bed old guy and I fill at 9:00. Four hours only gets it to 1:00 AM; six hours would be a whole lot better, would then only be burning oil for 2-3 hours instead of 4-5 hours. Like the 80, the oil boiler (320K) runs full tilt, virtually nonstop when it's ugly cold.

Jim
 
Do you have anything other than elm to try. If I remember correctly elm is fairly low on btu content. Very high ash content.
 
I hit the hay by 9:00 most nights myself, but have a nice bed of coals at 6:30 a.m., assuming it's not below zero. If it is, I get up around 4:00 to load it up. Since you're in the North Country, try to get some beech or yellow birch or--better yet--hard maple in the future. That's a lot better than elm, and it ll splits a lot easier, too.

Wood can be hard to come by these days unless you have access to a woodlot and cut it yourself. Too many competing markets--chips, pulp, saw timber. Loggers have better ways to spend their time than messing around with firewood deliveries, unfortunately. Your best hope is to find someone who doesn't mind being paid in cash because, in the words of one Minnesota logger I interviewed once, "Cash don't bounce."

Good luck. You must have a whale of a heat load to have a 200KW boiler.
 
Fred - Elm is funny stuff. My sense is that there are sub-species. None of it is worth a tinkers damn if not very well seasoned but there is night and days difference between elm that grows on high ground and that which likes wet feet. I have burned elm for 40 years and have figured out that high ground elm, if the bark comes off within two years of dying, left standing for 3-4 more years will turn a silver color and lose most branches under 2". That is the time to cut; rounds when tossed into a pile will sound like bowling pins and it seems to have more btu's than cherry or ash. That said, it does have a very high ash content.

I do have, and am about to get to, a cord or so of 2 year seasoned sugar maple in the woodshed, but it was cut for our econoburn and is a PITA in the 80 because it is 6" too short. I have been through 10 cord of this short stuff already and it has its own challenges.
 
Thx Eric, Hope I've not made that mistake before. My apology.
 
I hit the hay by 9:00 most nights myself, but have a nice bed of coals at 6:30 a.m., assuming it's not below zero. If it is, I get up around 4:00 to load it up. Since you're in the North Country, try to get some beech or yellow birch or--better yet--hard maple in the future. That's a lot better than elm, and it ll splits a lot easier, too.

Wood can be hard to come by these days unless you have access to a woodlot and cut it yourself. Too many competing markets--chips, pulp, saw timber. Loggers have better ways to spend their time than messing around with firewood deliveries, unfortunately. Your best hope is to find someone who doesn't mind being paid in cash because, in the words of one Minnesota logger I interviewed once, "Cash don't bounce."

Good luck. You must have a whale of a heat load to have a 200KW boiler.

If the 80 doesn't shutdown, I also have a nice bed of coals, and it's holding the set temp, at 6:00 am, even at 10 below. Problem is when it gets really cold (and windy).

I have 70 acres of woodlot and have heated with wood for over 40 years. I usually cut beech, maple, ash or oak for the winter wood. This year is an anomoly. The winter wood that I had for this season was sized for a different boiler, didn't cover the nozzles on the 80, is almost gone and was a royal PITA.

We have a seemingly endless supply of dead elm around the hay fields that I have always utilized for the shoulder seasons. The elm I have was sized for the 80 but intended to be for the spring shoulder season. I started burning it because, being full length, it is less prone to blow holes than the short wood.
 
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