E-Classic Update

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Look at the sticky Simplest Pressurized Storage System Design at the top of this forum, and you will see by the wood boiler Input Protection Mixing Valve. This is the Termovar, in my case.
 
Regarding creosote buildup: My firebox creosoted up fast when I first got the boiler going, but it hasn't gotten any thicker in more than a season of use. I'd say it's probably about 1/4 to 1/2-inch. In really cold weather, it seems to burn off to some extent, but it's just a fact of life with a gasifier, I guess. I'm intrigued by the observation that it seems to be growing in the E Classic. I bet it levels off at some point and you'll know what the baseline is. I agree that the larger water volume in a big boiler like the EC is probably the culprit.

On a related topic, I've never understood how you can torch off creosote growing in your chimney, but the stuff in the firebox seems immune to burning. I mean, you can put a torch to it and it won't stay lit. You'd think it would periodically burn off, but it doesn't. I bet it would gasify pretty well if it did. I have noticed that a good, strong burn following a long period of idling will produce white smoke out the stack of my boiler. My guess is that it's creosote in the hx tubes formed during idle, that's burning off when the boiler gets a good flame going. It goes away pretty quick, but I was confused at first. Since the gasification chamber was full of orange flame, I couldn't figure out where the smoke was coming from.
 
When I shut down my system late last spring, I followed Tarm's recommendation to scrape the firebox to remove as much creosote as possible, then seal up all air inlets to the boiler to prevent moisture infiltration. Moisture + creosote = acid.

Some areas scraped down to bare metal, and I doubt any creosote was as much as 1/4" thick, except maybe in some corners. It does not come off easily, and you're right, you can't burn it off with a torch. I just scraped as much as I could and sealed up the boiler.

When I first opened it this fall, it looked exactly like I left it last spring. No evidence of any corrosion, at least not visible.
 
I have a E-Classic 2300 dual fuel unit. It's been operating for about 3 weeks now and the past two weeks continuously. Temperatures running in 20s and teens here in upstate NY at night so we're online for the winter. This week we hooked up the propane and are running with gas backup. Here are my observations so far:

1. This boiler is the cleanest in my small town of Ticonderoga. I looked at all the Woodmaster units around me (we have a dealer 10 miles away) and they all smoke. Mine smokes when on a cold start but we've been pretty pleased with stack conditions. I have 4 sections of stack on mine to meet my building permit requirements with a spark arrestor on top.

2. No problem with damper sticking but I've been burning small splits of dry wood. I did open back yesterday and tubulators have some flour dry fly ash but not bad buildup. Took about 1/4 of a 5 gal pail of ash from reaction chamber so far. Unit has some creasote buildup in the firebox but it scrapes off without problem. Seems to be lessening now with more frequent burns.

3. My unit is located over 200 feet from the heat exchanger with my oil boiler. So 400 feet of total PEX run. I have a #11 pump at the EC2300 but Central Boiler recommends upsizing to a #14. I think after conferring with brother Randy we'll put a #11 on the return at the house to increase flow. On talking with CB yesterday I related that my unit runs fine but it takes a long time to increase temperature in the radiator loop at the house. I have problems keeping the water in this loop up to 150-160 deg and it should be at 180. To get it there I increased the EC2300 setpoint to 195 but it trips on HI temp and doesn't reset until 165. Big problem - this causes the propane backup to fire to bring boiler back to 195 using excessive amounts of propane!!! CB thinks putting larger pump (or two pumps in line) will increase flow thru heat ex and transfer more heat (I remember that from my heat and mass balance engineering class! - Q=UAdeltaT). This should increase temperature transfer to water loop and I can run EC2300 down at 190 to avoid HI limit trip. Also instructed to not leave gas backup online - only use when away from unit for period where it will run out of wood.

4. Even with slow heating so far, I haven't had any problem keeping house at 68. I fill firebox to top of firebrick once or twice per day. Takes a lot of wood each time but only two trips to carriage house to do it. I build small leanto wood shed next to unit and it does a great job of keeping wood dry. Storing about 4 cords under shed and ordering 2 more this week. Even if I burn 6-8 cords per year I save huge $$ over the 1800 gallons of fuel oil I used to burn. 3 year payback if oil prices head back over $3.50 and that includes lots of plumbing. I figure I have about $16K in mine total. My EC2300 cost $12,500.


Ron
Ticondeoga, NY
 
I paid $9300 for the eClassic wood-only this fall. By the time it was installed with all accessories, hot water exchanger, etc, tax, ~$14000.

I would highly recommend a $50 Raytek MT6 infared thermometer if you are interfacing to a boiler. It is a great tool for figuring out where the heat is going. I put black tape on the copper runs and it appears accurate to a couple degrees F (the infared thermometers does not work well off of bare metals). The infared readings on PEX is about 10 degrees F lower than inside temperature since the PEX has some insulating value.

My installer insisted on upgrading the pump to a #14 (32 gal/min ~20ft head) versus a #11 (21 gal/min ~10 ft head) even though I could measure and determine the wood boiler did not need more flow. As it turns out, my propane boiler pump was not operating at all - the house was heating entirely by convection, which was actually quite effective. BTW, the #14 pump consumes ~150W compared to ~75W for the #11.

I also put a watt-meter on my eClassic. About 75W when idle (pump only running) and ~220W when burning (fan, plus pump). The two lights add another ~75W if on.
 
Ken - I installed the #11 pump on the 3/4 pipe outlet and will be moving to the 1 1/4 outlet in the spring. Reducing down to 3/4 thru the 1"pump could be part of the problem. I also put another #11 pump on the return line to increase circulation flow back to the boiler. The more I think about that, less I think it does anything since the boiler is not pressurized. I may end up with the larger pump on the boiler discharge to the house this spring because of the long PEX runs.

Good idea on the back tape on the copper pipe. Infrared thermometer definitely has trouble with fresh copper. I do want to do a heat balance around the system to see if I am losing heat. I went with a simple design on the PEX piping - running inside 4" sewer and drain PVC and cementing/taping joints. Then foamed ends. From checks I've done so far, only losing about 1 degree across system from boiler to house but want to take another look. It takes a lot of wood to justify $2600 in thermopex installation.....
 
I gave in and bought the Thermopex, but I also put 2" rigid pink foam around it. I think you can measure the performance of your homemade Thermopex (by the equation at the end). I will try to measure mine sometime.

It seems hard to measure delta temps when they become so small. But considering 20 gallons a minute, if the temperature drops just 1 degree F in the thermopex run, thats (according to my calculations) 1F*20gal/min*8lbs/gal*60min/hr*BTU/(lb*F)= 9600BTU/hr loss, or 2800Watts. Or simpler - for 450 gallons of water, that's 1F ever 22 minutes.

Of course, the 1F depends on length, R-value, etc. Central boiler provides scant specifications on their Thermopex...I think someone should model it or pressure CB to specify it. I think placing PEX in 2" foam would even be better than Thermopex. They also spec it to 180 degrees, but my installer dialed my system to 190 degrees, where after it soon over-shot to 193. I dialed it back to 188 and will dial it back more when weather warms or I get a working pump on my propane boiler.

I understand one can measure the R-value of anything using an infared thermometer, R = 0.67(TSurface - Water)/(TAir-TSurface). For example, on Thermopex, if the air temp was 10F, the water 180F, and the surface was 25F, then
R = 0.67(25-180)/(10-25) = 7. Same equation works for measuring house walls. The 0.67 assumes calm air around the surface.
 
Here is an update after 3 months with an eClassic.
1) Plenty of creosote even though my wood is dry. I agree this is just a characteristic of this gasifier design. I have performed two thorough cleanings which took me about an hour each. A bit of work getting the hardened creosote off the back and front edges and crevases. I sprinkled Ashtroll into these area and scraped it in.
2) Operating fine, seems efficient. I do notice some smoke smell briefly upon restart and stop, but nice burns in between. I do clean the ashbox every 3 days or so. I typically try to: 1) Let the fire burn down, 2) remove the ash, 3) stir the coals so much of the ash and coals fall into the reaction chamber, 4) spread the coals and ash so they do not plug the hole, 5) replace the reaction chamber cover, 6) add wood.
3) I clean the exchange baffles about every 2 weeks. The brush has gotten stuck after plunging through, so now I only do it with the reaction door open incase I need to free it.
4) I had two bricks in the reaction chamber come loose. They overhang the brick on the bottom and it is possible my shovel accidentally pried them loose. They are just balanced there now. A single dab of some adhesive was on their back.
5) All the side bricks in the burn box have begun to buldge. I eventually took the worst 4 out and there was about 1/2 of creosote that had formed behind them. Once the creosote was exposed to the more intense heat, it turned liquid and started flowing away. I was then able to clean out the areas easily and insert the brick fully back in. I think that perhaps with a full box, the pressure on the brick may force the creosote out and limit this - not sure. I was burning less than half full for some time.
6) I installed a $47 battery temperature sensor and alarm (Sper Scientific) in my house. I taped the sensor to the source line which reads 130 degrees +/- 3 degrees (the line is actually about 185 degrees). I set the alarm for 125 degrees. Thus, if the fire goes low or the power fails, the alarm goes off quite quickly. This has been a big help in monitoring the system. I had started by taping it the return line, but the temperature there fluctuates too much. Also, one time the fire was low and the propane boiler was actually heating the eClassic, and the alarm did not sound because my propane boiler was keeping things warm enough.
7) I would have probably changed the orientation of the boiler - the front is no longer looking pretty. The area above and near the door is black from flames crawling out when being loaded. The light dome on the front is covered black. Cleaning only does so much. Orientating the door towards prevailing wind might limit smoke in the face.
8) I never use the lights. I wear an LED headlamp which I find indespensible for our short winter days.
9) Opening the door at the wrong times is a disaster (smoke, cough, cough). The best time to open is about 10 minutes after a relight. I sometimes boost the temperature setpoint temporarily to start the fire and come back in 10 minutes. The worst time appears about 10 minutes after the burns stops. I always change into my "special coat" for loading. It is a developing skill...
10) Letting a hot fire burn near the back of the firebox with the damper open cleans the stack well. I have had the stack top glowing and creosote embers falling out of the stack - not sure if this is good technique, seems to work.
11) The damper door sticks - sometimes worse than others.
12) I have a small hoe that I can scrape creosote from the ceiling with even when burning. Not sure if this is just a waste of time. The majority seems to drip back on the fire.
13) Had a leak in the brass flange above the pump. Water wrecked the pump. My installed alarm sounded which might have saved me from a frozen system. The plumber was not aware this flange had a threaded peice which was not completely tightened.
14) The connection to my propane boiler has been very interesting, but that is another story.
 
I had the same problem with one of the bricks next to the reaction chamber opening falling down and mine cracked in two. Funny thing they don't fit back together but I can jam them in so they don't fall again. I knock them out every time I clean out the ashes. Bottom of two of the tubulators has burned away. I don't know if this is a warranty item but should be.

CB has recommended we remove all firebrick from firebox above the air hole openings. One of the dealers told me he thought the engineers just put them in to look nice... Mine buldged like yours and I had a few cracked. Good to konw I don't have to replace them. I had lots of cresote behind mine. Some were tough to get out when I removed them but the boiler seems to do ok without them.

I will probably go with Thermopex this spring when I dig up the line. My cheaper method caused snow melt for about the first 80' of my 180' pipe run underground from the boiler. The wood guy got his truck stuck in the ditch and it was all soft. Ground around it frozen. Cold winter here in upstate NY. It probably costs me an extra 3-4 fills per week and about 2 extra cords or so a year to lose this heat. Your heat calculation confirms it for me. When I get it up to temp, I can literally watch the temperature of the boiler drop 1 degree every two minutes sometimes when cold (and the heat system in the house isn't calling for heat). I know I am losing heat, question is, can I justify the 12.25 per foot for Thermopex...
 
LakeGeorge said:
I will probably go with Thermopex this spring when I dig up the line. My cheaper method caused snow melt for about the first 80' of my 180' pipe run underground from the boiler. ...

Can you tell us about how you made your underground pipe, and what you think went wrong?
 
I ran 1" PEX inside 4" drain PVC and sealed each end with some foam and glued/taped joints. I did not use additional insulation around the pipe but I did bury it about 4' deep.
 
LakeGeorge,
I'm sure it will be worth your while to upgrade your underground lines. I would really research the option of closed-cell polyurethane spray foam. Jim K in PA has photos of installing his this way. Also, Heaterman has lots knowledge with this method.
If your seeing 1* drop every two minutes that would equal 112k btu/hr (450 gallons x 8.33 #=3748.5 btu/degree). Times that by 24 hours=2.68 million btu/day.
Heaterman also makes some really good points regarding tubing size for underground lines. Depending on your heat load, if you tear out your lines you might look into 1.25" pex.
I have no practical experience in this area but from my research on this site these things could really increase your systems performance.

Best of luck,
Noah
 
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