Heating transferring when circ off

Unknown

I am working on a 3 year old system ( which we did not install).  It is a New yorker fr series with domestic coil.  Circs are on return side :(.  Two 3/4" baseboard series loops.  Taco 3/4" flowchecks on supply side after air scoop/vent and boiler fill/ expansion tank.  Customer is running a higher (175) lo limit to satisfy hot water demand.  Problem is, even with stats off and circs not running, house is still heating.  I have opened and closed the flowchecks.  They are apparently not working???? Any suggestions?

Al Letellier_21

flow checks

Short of opening them up and cleaning them out, you may have no choice but to replace them. IF it's easier, you could try installing a second flow check on the returns, but if the copper sweat type are in place, change them out....once they start, it's hard to stop the gravity feeding

Big Ed_4

Flowchecks

Smallest flow check I would use if the radiation is higher then a flow check is 1" ... But I would clean them out first .… Clean the seat , weight and weight shaft with a fine steel wool .. Keep a look out for strands of teflon tape too .

















s

Ron Jr._3

We use Taco 3/4 flow checks almost daily

and almost never have a problem with them stopping gravity flow . But for the handful of installs that had heat bypass , upsizing the flowcheck like Big Ed said always did the trick .



You could try using a good boiler water cleaner first though . Not sure if it would get to what's hanging up the flowvalve ........