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[agriffinjd]

Third year with an OWB, first time I've left while it's running.  We left town Thursday morning.  I shut off the blower/thermostat and left the two circulation pumps running.  When I left, water was a 190.

Got back last night around 8 PM.  Water was at 109 and the propane heat was just about to kick on.  By the time the furnace in the house shut off, water was at 119.  I've got a forced air setup in the house with an aquastat so the propane kicked on once the water temp dropped below 130.  The propane heat was keeping the water quite warm.  Temps while we were gone were only in the 30s or 20s, though lows were down in the low teens.  So not sure if it would work better in sub-zero weather (where the propane furnace kicks on more often) or worse (if the lines lose heat more quickly). 

Feels good not being tied to the boiler if we need to leave town for a few days.  The past two years I was worried about freezing lines if I left.  All for nought. 

BTW, when I got back, the stack was still smoldering.  Fire lit back up in about 30 or 40 seconds after I opened the door.

[hondaracer2oo4]

Your set up is back feeding heat through the water to air hx I assume correct? I too was worried the first few years that I had my set up which was strictly a forced hot air set up with a water to air hx. I also found that the back feeding of heat through the water to air hx kept the owb water quite warm, what didn't work so well was the fact that the 100 degree owb water was cooling the indoor furnace air right down and keeping it from putting out much heat into the house. This caused it to run almost constant. My new set up is a hydro air system. I replaced the old oil furnace with a used oil boiler. I built a hydro air box to put the water to air hx inside. I then built a primary/secondary loop system so that the hydro airbox is on a secondary loop and the oil boiler injects heat into the primary loop through a secondary loop as well. I have a flat plate on the primary loop. If the oil boiler has to kick on because the incoming owb water drops below 150 the heat from the oil boiler gets injected into the primary loop and passes the hydro air box secondary loop before it hits the flat plate hx in the primary loop. This gives the hydro air box full temp water first then hits the flat plate with 165 degree water to keep the owb warm then hits the return to the oil boiler to be rewarmed. The system works flawlessly this way. The only thing I think I would change is to put the owb loop on some sort of timer when it dropped below a certain temp so that it wasn't constantly pulling heat from the oil boiler but I use the oil boiler so seldom it's not worth saving the extra few gallons of oil.

[agriffinjd]

Yes hondaracer2oo4, that's my setup.  I didn't light my stove until November 30th this year.  The water temp started off at 50 when I started using propane for heat in late October.  It was keeping the water temp right around 104 or so just prior to my lighting the stove.  I didn't notice the furnace running that often at the time though I wasn't trying to watch for it.  I was mostly experimenting on how the propane heat could keep the water lines warmer.  So I'm not sure if I would have the same issue that you experienced.  I hope I don't, as what you did to fix it is way beyond my capabilities.  I'd just make sure the propane tank was full if I had to leave for a month or more, as I burn 2.5 to 5 gallons of propane a day when heating with it...

[silver star]

Yes lesson I learned which I posted about, was to leave the circulation going. One of my employees says due to the distance their unit is away from the house, they keep circulation going all through the non burning seasons.

[aarmga]

What is the benefits of leaving the circulation pumps on all through the year?  Seems like a large waste of energy to me.  Especially using 200w of energy.

[mlappin]

Personally I really don’t see the reason to keep the circulators running 365 days a year. I’m sure there is a good reason, just not coming to me.

I’m running a primary secondary loop on mine, figure if I leave I’ll have to either get father trained on the proper way to load a gasifier or install a jumper so the secondary pump for the heat exchanger runs constant, in hindsight I should have just installed a ball valve between the T’s and could just close that when gone. Another thought is to install another aqua stat set for around 50-60 degrees so more heat makes it into the house instead of trying to keep the boiler water over a 100 while gone.

My other thought was when leaving was to place a metal five gallon bucket over the stack to make sure as much heat as possible stays in the stove and cant escape.