Loop gets hot without circ. running

Rob_5

I have a 5 zone hot water system (circ returns & Check valves on feed)and a bedroom zone (2nd fl) seems to circulate water, getting quite warm, and neither stat nor circ is calling or on. I question the sweat check at the feed. Any help or thoughts.

Thanks, Rob

Michal

had similar issue

I had a similar issude where the flow valve was hanging up, so I replaced it, depending on line size, it might not be that expensive. Also check boiler water temp is around 180 because sometimes I have seen very hot water be able to push open a flow valve. hope it helps

Joe Mattiello

Zoning with valves or circulators, and check valves?

IF zoning with circulators and check valves, you could have a check valve with system debris lodged under the weight, hindering the valves performance. If you have 1 pump, and 5 valves, it’s possible a valve is stuck open, and every time any zone calls for heat you heat that zone also. Unfortunately, I don’t know enough about the system to successfully diagnose the problem. Is this a new problem? Have you made any changes to the system? Is it primary, secondary piping, or supply, and return manifolds?
Taco, Inc.
Joe Mattiello
Technical Service Technician
joemat@taco-hvac.com
401-942-8000 X 484
www.taco-hvac.com

Dale

may need 2

Gravity water heat works pretty well. First step as other posts suggested, simple and cheap, is to open up the first check valve and make sure it's clean and dropping close, a few wrapps of solid solder helps with the drop. If that doesn't do it then a second check valve should be added, so they'll be one on the supply and return, to prevent this gravity heat.

Kal Row

spring checks on both ends....

get rid of the old cast iron check and put in a taco 00xxIFC pump at one end and an inline springcheck at the other end – you will loose very little active flow

cooler-denser-heavier water will drop right through warmer-lighter water - even happens in a single 1/2 inch pipe - which is why homes where all pipes are pinched to a single point drain, rarely have a freezing problem if the drain point is in a warm room