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[MrUPS]

Hello everyone! So I got the wood stove fired up today for the first time after fixing an incorrect plumbing job and I thought all was going well....but its not. I have my OWB plumbed into my existing propane boiler system via a shell and tube HX. I'm running a circulating pump 24/7 in a small loop through the HX and the propane boiler to keep the water in the boiler hot so the propane doesn't light, instead when the house calls for heat the circulating pump for the propane system kicks on and pumps the water through the house. All of that seems to be working correctly, however, the heat registers are always hot! I have the thermostat set at 62 and the house is 70! The house circulating pump is not running, just the small loop pump. I dont understand. Is it possible that the warm water is rising and circulating the way the old gravity systems used to work? I'm really at a loss here. Thanks guys. Sorry for the long post. I'm gonna try and get some pictures up.

[willieG]

where are you sucking water from for your shell exchanger and where are you feeding it back into your homes system?

does your indoor boiler have a holding tank?

[Scott7m]

Why did they use a shell and tube heat exchanger!!?

[MrUPS]

willie. The shell is plumbed into the cold side of the boiler system. My two loops (one from upstairs and one from downstairs) join together into 1 1/4 copper then strait into the top of the shell. The hx has a 1 1/2 90 on the bottom off it right into the boiler. The hot water from the OWB is plumbed into the lower nipple on the side of the hx and heads back to the OWB through the upper nipple on the side. Does that answer your question? I'm sorry if I miss understood.  Scott, I bought the shell and tube last year from by dealer. That is what she told me CB wanted people to use for HX. Cause they dont plug up like the plate style. Its water under the bridge at this point I guess. Live and learn.

[MrUPS]

maybe pictures?

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[MrUPS]

wow. not sure why they're sideways....sorry guys.

[slimjim]

Sure sounds like it is flowing by gravity on its own, you could try either a spring check, or plumb in a heat trap in the piping to stop the ghost flow

[Scott7m]

Sure sounds like it is flowing by gravity on its own, you could try either a spring check, or plumb in a heat trap in the piping to stop the ghost flow

slim do you think the tube and shell could be making this problem worse?  Like how a sidearm forms a convection current, maybe its doing the same

[MrUPS]

Slim I found a spring check valve but I dont know what a heat trap is. Is it the same idea as a plumbing "P" trap plumbed into the piping? I let the system run as it wants all night and its up to 72. I dont think the circulating pump every ran. Its got to be doing this "ghost flow". All the registers are warm and there hasn't been a call for heat all night. I am kinda surprised though. I thought the loop pump would have disrupted the flow enough to stop any kind of gravity flow. Guess not. Where would be the best place to plumb in a spring check or a heat trap? Are there any other possibility's?  Thank you for the replies. I appreciate it!

[slimjim]

Any where in the loop on the spring check, a heat trap is just a drop vertically a foot or so and then back up to your loop, the joke is, how far do i drop the heat trap, answer, about 6 inces more than you did, it's not a science, I usually do about 12 - 16 inces.

[MrUPS]

What do you guys think about just adding a zone valve? I was thinking about plumping it in just after the the "T" for the loop pump on the hot side. I think the water is "ghost flowing" the same direction that the water flows with the pump on so I'm not sure a check valve would work. What do you guys think?

[slimjim]

You will more than likely need to add not only the zone valve but also a 40 va transformer and wiring, it will work but so will the spring check or heat trap.

[MrUPS]

Hey Slim could you explain to me how a spring check works. I was thinking it was kinda like a backflow preventer but that wouldn't work because the water is gravity feeding the correct way. Its it a valve that opens under a certain amount of pressure? If so is that pressure setting adjustable? I have found them online so I know what they look like just not sure how they work. Thanks for the reply. I appreciate your time.