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[caper]

just got home from 12 hr shift,pretty cold out,-6, just changed diff to 182 today with a 15 degree diff, furnace now is 167 degrees so blower just came on,went to furnace room,two zones calling for heat, main floor with cast iron rads and garage infloor,that fine,checked suppy temp coming into house from heat exchanger,it is 130,return is 105, I realize I have a lot of cold water heading outside to furnace,but how bad is this, I just bought a bigger grun 2699 for main loop,im hoping this will solve problem,so how bad is this issue,its the only issue I have, in the process of getting some pics together for slim in meantime.thanks everyone again..

[Belknap]

When my radiant loops call I get a big drop in return temps.  I changed by differential to 5 degrees so that it will fire to get the fan on before the temp gets too low.

[Marktk]

I added a old water heater tank as a buffer for my inside loop so even when my big zone calls i only drop to about 150a going to owb with 189 spt and 15 diff. So my main loop to owb comes in to side arm then threw tank thenback out. My heat zones draw from the tank.seems to work pretty good.

[jamesbodeis]

I have a similar issue. I have 7 cast iron radiators all on one zone. When the house calls for heat, especially in mild temps when the stove doesnt run often, i get serious drop in water temperature.

[jamesbodeis]

I turned my stove up to 195 with a 5 degree swing. I still see a 30 degree drop when everything calls for heat but at least it only falls to 165-170 instead of 135-140.

[Marktk]

Falling to 165 or so should  be no problem

[caper]

hey guys, just put my new 2699 on the main loop from owb, so far so good, I set it for med speed,it hast been that cold as of late so I don't really know if this will stop my water temp drop issue, ill let everyone know when I find out...bye the way does anyone know the gpm for each of the speeds for the 2699 compared to the 1558, I know the maxs are 17 vrs 31.....

[LittleJohn]

...I think as long as your drop in return temperature is temporary it should not be an issue.

Central Boiler has a solution for this, a thermostatic mixing valve that sends water back to the boiler if the supply from the OWB drop below 140f.  Once boiler gets above 140, then it begins to open up until fully open at 180f.

[caper]

eerrrrrr happened again, woke up at 2am, all four zones were on at same time, temp down to 120......why is this happening......my only complaint.....i thought new 2699 pump fixed the issue,obv not....why doesnt this happen to everyone else, new system and appears to be hooked up right,,,,, what to do...buffer tank....but why doesnt this happen to everyone else with no buffer tanks....

[slimjim]

Which temp was at 120, the wood boiler, the supply at the house or the return from the rads and radiant?

[caper]

hey slim, the gauge on the electric furnace (which is off) displayed 120 ,maybe lower, its usually pretty close to the outside owb gauge if i hadda went out to see, furnace just couldnt keep up with the cold water  going to owb i guess,i realize its alot of cold water heading out to exchanger, but everyone else tells me that there owb drops as well when everything call for heat ,but not that drastic, then i always compare my buddies owb which is shared by him and his neighbor,wouldnt his always be calling for heat since it is two homes, i know ive been ranting about this same problem for some time now but its starting to tic me off, doesnt happen alot ,but with all the work that goes into burning wood , i shouldnt have to be checking on it all the time........end rant....just called wifey,climbing back up ,now at 160

[caper]

is it possible to hook up some kind of device that would only allow two zones to come on at one time, i think then i wouldnt have an issue......especially since i just installed a new 2699 pump..

[slimjim]

I would like to know your temps at the wood boiler, then the supply in the house then the return in the house, this will tell us a lot, don't get frustrated, I'll stick with you!