Ghosts In The Machine

Patchogue Phil_2

I've got what I figure is "ghost flow" in one of my hydronic baseboard zones.  The beginning 15 feet of fin-tubes are very warm even though there is no call for heat.  Room gets up to 75*,  T-stat at 65*.  Other zone in house is NOT calling for heat either,  no ghost flow evident there.  Problem zone is much closer to the boiler than the other zone.



There is a swing check valve (horizontal,  no spring) in place on each zone for the last 16 years.  Located on the supply for that zone.  Each zone has it's own Taco 007.  Unfortunately,  they are not pumping away,  but on the return piping .



Perhaps the swing check is stuck open?  There is a little oxidation crud around the pivot screw for the check valve,  but it is not currently weeping.



Is a spring-loaded check valve a better option?  Any recommendations?

Gordan

Is it possible that the ghost flow is occurring on the return side?

Are those 007s IFCs?

Patchogue Phil_2

ghost flow from supply, no IFC.

No,  the ghost flow is happening from the supply side.  And no,  the 007 does not have integral flow checks.   The zone is question is a 007-F5,  the other is a 007-F4.  Zones are all 3/4" CU pipe and fin tube.



The existing swing checks are inline with each zone after the supply header.  The arrow points properly with the supply flow.  They have worked for about 16 or 17 years.   The supply piping rises up to 6 1/2 feet from floor (3' above boiler top) into the horizontal air scoop,  drops down 15 inches to a 1 1/4" x 3/4" copper tee horizontal manifold,   then each zone pipe drops down to the floor and then up to each zoned area of the house.

Ironman

Check Valves...

Should be spring loaded or flow checks. A swing check installed horizontally offers little or no resistance in the direction of flow. There's probably some crud on the one that doesn't have the problem causing some flow to be forced into the other zone after the supply manifold.



The check valve should be installed in the discharge line of the pump(s), before any Tees or manifolds.

Jean-David Beyer

Is a spring-loaded check valve a better option?

A spring-loaded check valve is better than a swing, but if you are going to change anything, you are probably better with a (gravity weighted) flow check valve, such as a Taco Flo-Check valves.



http://www.taco-hvac.com/en/products/Flo%20Chek/track_file.html?file_to_download_id=15472

Patchogue Phil_2

No call for heat

There's probably some crud on the one that doesn't have the problem

causing some flow to be forced into the other zone after the supply

manifold.



There has been no call for heat on any zone,  yet the ghost flow occurs on just one zone.  

Ironman

What's Turning On the Boiler?

Does it have a tankless coil?

Patchogue Phil_2

Yes

Yes there is a tankless coil,  which feeds a 50 gal tank.  But that is a whole other conversation.  :-)