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[Rickster]

Hello I am installing & old woodmaster.  Can anyone tell me what kind of heat loss i should be getting thru the heat exchanger? ( 50 plate water to water)  The pipe loop is 1'' pex 200' (100 ft from the house) I get a drop of about 20 deg.  I was told that the water wasn't circulating fast enough. I changed from a taco 007 to a taco 0011 pump at the woodmaster. That didn't seem to make much of a diff.  My local dealer dosn't seem to know much    thanks

[ckbetz]

I can't be sure because I have my system direct plumbed, but I've always heard from the manufacturers that you'll lose 10 to 15 degrees through your exchanger.  I think you'll find what's most important for your efficiency is the return temperature.  To get the max out of your OWB you'll want the delta between your supply and return to be as small as possible.  That's what I have a problem with.  My delta is always 20 or more degrees and it causes my system to be less efficient.  I've yet to find the right flow combination to get my delta under 10.  It could be possible that I just won't be able to get it with my antique existing system in the house.  I've thought about adding a w/w heat exchanger but haven't taken that plunge yet.  Good luck, let us know what you come up with.

[willieG]

i think your biggest concern should be not how much your temp drops on the return to the furnace but if your  furnace can keep up when it kicks in and heat the water to "shut off temp"  while your domestic is still in use


what is the difference if you drop 5 or 25 degrees. the  only diference i can see is that the water is moving faster. the temp  (the way i see it anyway) would reach the set "come on" time at your boiler in the same amount of minutes either way


no matter how fast the water is moving you have to take the same amount of btu's out of your furnace water to heat your domestic water

it is possable to move your water so slow you could not heat the domestic water. but after you find the gpm to get above this point i don't see any advantage of going faster

of course i am no furnace guru and maybe from an efficiency thing there may be reasons and some one in the know will explain it  so i can understand better

[yoderheating]

 It is normal to have a 10 to 20 deg. loss. If your using a one inch water line a 50 plate is more than enough. We often use a 20 or 30 plate and they work fine.  Everything sounds normal to me.
Do you need the water to be hotter or is it hot enough the way it is?
One other thing, make sure the water is flowing through the heatexchanger in the proper directions. This will make a difference. The water should  be flowing the opposite directions through the heatexchanger.

[jon d]

What type of underground pipe are you using?? Thermopex,MaxxR, pex wrapped in bubble wrap inside 6" pipe??    20 degrees sounds like alot..