Post in 'The Boiler Room - Wood Boilers and Furnaces' started by Bill the Dog, Feb 10, 2012.
I didn't know you were down there.
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Really quiet on this thread.
Will, you do know I was poking at the words "our root cellar"?
Bill..... Knock.... Knock... U out there?
Check out the info near the last 2 pages, it will explain ( far better than I can) when and why we use multi pumps on a header. Its very rare, but only applied when you know exactly how and why your doing so. I would recommend a flow switch for safety, it will save money in the long run. I would rather have a boiler bypass than a Danfoss any day. Cheaper and fail proof. I noticed someone mentioning trying to supply 180kbtu thru the header, why ? Is there a heat load that calls for that much ? If so you would need a 2" pipe to supply that amount. 1 1/4" pex can only supply 8 gpm max or 80,000 btu/hr at 3.3 fps or 11.2gpm @ 4fps. Hopefully he has the good pex with a full 1.25" diameter and it can supply more gpm and stay within acceptable velocity. This also allows for smaller pumps and less electricity.
Pressure tanks air scoops and make up water should all be tied at the same place, and the circulator always pumping away from this point, referred to as the point of no pressure change. When figuring head , many confuse static head and friction head loss combined and calculated in open systems its called Total Dynamic head. As far as flash boiling, this is usually a problem in unpressurized systems. closed loop system actually have pressure requirements 12 cold and 20 psi at 180 degrees is standard. Running less can cause component failure, like circulators which are designed for certain pressure minimums. Running a "00" pump with zero or low pressure can cause a shorter than expected life and or cavitation problems.
I've take the summer off from heating and just two weeks ago fired up my EKO 80 again. Over the summer, I've read and reread everything in this thread as well as the EKO tuning thread. I've spoken with Dave at Cozy Heat a couple of times. Nothing stands out as to why my 80 is/was overheating. This fall, I came up with an idea that my bypass was getting pushed open when the boiler "huffed". I don't know if that is a real term or not, but occasionally I can hear it "huff" after I close the top door. So, when I fired up the boiler this fall, I locked the bypass closed by snapping a vise grips onto the bypass handle so that it could absolutely not be pushed towards the back of the boiler and thus allowing the bypass door to open. I also put a new, stronger spring in the bypass mechanism to hold the bypass door closed even better. The 80 fired up, house warms up, everything fine. Temp set at 195 F. About 12 hours later, no joy. The boiler computer had the dreaded E2 message and was at 208 F. The pop off safety valve did not open up though, so no water anywhere. Hmmmmmmmmmmm, crap.
Next thought, maybe a 195 F setting is too high? I turned the control knob down to 185 F and try everything again. It's been a week now and no problems whatsoever. The 80 seems to hang out at 188 - 190 F in spite of the controller set at 185F. The 80 is running very well, gasifying easily. Maybe even burning a tick less wood per day, although that is a guess. I don't have any good hard data to back that up.
Anyway, one week into this adjustment and everything appears to be fine. Wife and myself are happy burners again.
Bill the Dog
Im somewhat new to heating with an EKO but is there a possiblity you have an air leak causing your boiler to overshoot your set temp? Maybe the door gasket?
I've got an eko80 also and think you have found the problem by turning down the temp on the controller. I take it that you don't have storage. I've seen that the temp reading at the controller ( which is the temp of the top of the boiler) and the temp of the water leaving the boiler from the heat ex. can be as much as 10* different. With out storage when you get to idle mode the water leaving is very high and when you shut down the fan pushing in cold air to the upper box the upper chamber comes up to high temp rapidly and then the probe measuring the temp for the controller which is on top of the upper chamber shows over heat. There is ALOT of btu's setting in that BIG upper chamber and just because you shut off the air doesn't stop that from heating the top. By lowering the controller temp down it gives time to let the boiler to even out so to speak. If you had storage the excess heat would have gone into storage and every thing would work better. Hope this helps.
Thanks for the information. My 80 also runs a delta of about 10* from the Controller to the water output virtually all the time. I do believe that I've solved my problem. I feel kinda stupid chasing this problem for almost a year and the solution was so simple.
I have one really big question for you, or anyone really. I have two 1000 gallon tanks sitting in my detached garage, right next to the boiler room. They are not hooked up yet. Convince me that I really need to hook them up for storage. I've just not gotten around to it and I can say that I'm really happy with my system without storage. I'm eyeing up the garage space I could free up if I got rid of these tanks.
Bill the Dog
If you're happy with the system as-is you may not find storage worthwhile. You shouldn't have to be convinced. Storage is primarily for convenience and a touch of added efficiency. It will not change your life significantly if you're 100% happy running your boiler storage free.
Glad you figured out the overheat problem, but ah... did you read my post, last year?
Oooooooopppppps, didn't see that or at least didn't recognize is as a possible solution. My mistake. You called it and I missed it, multiple times.
Bill the Dog
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