Hello - I am seeking help with diagnosing a problem with my hot water baseboard heating system. In short, when I run the hot water in my house, the heat comes on...even after the thermostat has been disabled and the zone valve replaced. The problem is detailed in the attached schematic/photo.

Any help would be appreciated!

[redirider.smugmug.com]

Many thanks!

pretty basic system. either the zone valve is bad or there is debris in the valve..

I believe you are getting a convective flow. Add another zone valve, and move them to the supply side. It solves the problem and gives you control of the south side.

Thanks for your reply and suggestion. I thought the same thing, so I replaced the zone valve, but I still have the problem. Since I've already replaced the zone valve and now I've noticed that just one of the two supply lines in that zone gets hot when someone takes a shower, I'm thinking it must be something else???...



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Paul48 - Many thanks for your suggestion. That seems to make sense.

Based on your drawing, the first floor is a split loop. Although the zone valve is closed, there is still a path for gravity circulation. Based on your drawing, it would go to the 1st floor South, being the first in line.

if one of the supply lines gets hot then a return has to get hot also.
the water has to move thru the piping in order to carry heat with it.
can you see and feel all the piping in the offending zone?

paul, i disagree. it doesn't matter if the zone valve is on the feed, the return or in the middle. it will stop the flow and no heat will move thru.
i do like your suggestion of puttig two valves on the loop. two t-stats and more control.

It's a split loop. If it was the zone valve, north and south would get hot. I think he created a gravity re-circ.

Paul, if I follow your logic correctly, a gravity flow causes hot water to flow into the First floor South Supply until it meets the closed zone valve. Then it continues to flow into the other half of the split loop, the North side (with the direction of flow in the North side being "backwards" until it completes the loop.

Wow! I can't say that I totally understand it, but it makes sense to me. And yes Packy, I can access the return pipes. When I touch the two return pipes which lead to the single zone valve, they are both equally warm. I think this supports Paul's theory.

i'm not so sure i understand it either ??
my theory of locating a zone valve anywhere in the loop still stands.
BUT, when the loop is split, all bets are off..

Thanks again Paul and Packy. I have revised/improved my diagram based on my understanding of Paul's insight and suggestion.

[redirider.smugmug.com]

Paul, would you suggest moving all zone valves to the supply side or would it be sufficient to move only the two for the First Floor ?

Very much appreciated!!!!

Flip a coin.....Your choice.

You should put this issue on www.heatinghelp.com. You will get allot more responses.

Agreed...100%....The more minds the merrier. Look for a consensus.

Thank you Paul, Packy and Ravi.



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