Ghost or Gravity feed - not fixed with replacement TACO FLOCHEK

Amateur_In_NH

Hello all, newbie here looking for some help and advice. Appreciate all views and assistance!! Sincere thanks!!

Mods/Staff, if I’ve placed this in the wrong forum, please correct & accept my apologies. I have read & studied other posts in this problem area which were very helpful.

Our Problem: Home bought in summer 2023; issue did not arise until Jan 2025. Ghost, or Gravity, heat now rising into 2nd floor zone. Circulator not running; no call from thermostat (verified by tech’s measurement). T-stat set at 65*F, bedrooms settling in at ~ 76*F. New England outside temps 0-20*F, this time of year, for this location.

Issue has not been fixed by heating tech replacing TACO Flochek on 1/30/25. Tech also replaced Hi-Vent, due to apparent leaking. Both zones were bled after repair.

Hydronic heating, smallish 2-story house, full unheated basement, 2 zones only with tank-less coil for domestic. The pex piping seen in pics ran outside to a, now-removed, hot tub from the previous owners.

Help, please? Why now and not last winter? Could the new 218 flochek be defective or need adjustment? All suggestions are more than appreciated. God-forbid, do we need a check valve on the circulator-side; if yes, why now?

Equipment (pics to follow):

WEIL-McLAIN GOLD oil-fired boiler, circa approx. 2002; TACO SR 502 Switching Relay; TACO circulators; TACO Flocheks; Honeywell digital (dumb) thermostat, 2-wire, battery-powered display.

Overview pics (sorry about the arrows):

mikedo

are you sure he took the piece of cardboard out of it before he put it in

Amateur_In_NH

No, sir. We have a callback scheduled for Monday. We will definitely be in the vicinity to watch their efforts!

Thank you! Any further thoughts? These were the same folks who do the yearly maintenance but great idea to verify their work!!

hot_rod

are the return lines above the circulators hot? You could be getting some ghost flow up the return.

If you have isolation valves at the pump turn them off if the returns are hot and see if they cool off?

Amateur_In_NH

Hello hot_rod, zone 2 return is warm but not HOT. Can hold it, unlike supply side, which is way too hot to hang onto. Zone 1 return is also somewhat warm.

Will verify shortly if there's a discernible difference in felt-temperature between Z1 & Z2 return. Appreciate your feedback! Will update ASAP.

Any thought on why now and not last winter or earlier in Dec 2024?

Amateur(stumped)_in_NH

EBEBRATT-Ed

Its probably the flow check

Amateur_In_NH

hot_rod, would the ball valve, in orange rectangle, be the isolation that you'd want us to close, to gauge temp on return?

Amateur_In_NH

https://forum.heatinghelp.com/discussion/comment/1839493#Comment_1839493

Thank you, Ed!

Are current stock of TACO 218's liable for failure out of box? I imagine anyone can have a 'lemon', unfortunately…

EdTheHeaterMan

Amateur_In_NH

EdTheHeaterMan

Thank you, sir! No joke - a picture is worth a thousand words, as the saying goes. Will check the top. Probably need to wait for technician on Monday for the cardboard check.

Much appreciated!!

Big Ed_4

Pop the top and clean the weight , shaft and seat with fine steel wool .. . Could also be a strand of teflon tape laying in there . It looks like a 1" flow valve . If it were 3/4" I would recommend up sizing to 1" …. Sometimes ,with long runs and high risers , two flow checks are needed ..

Amateur_In_NH

https://forum.heatinghelp.com/discussion/comment/1839509#Comment_1839509

Will follow your advice!! Many thanks!!

Are we (here in NH) missing any other potential causes? I ask because, just thinking through it before the tech arrived, we had surmised that it probably was that flochek, and he independently arrived at that same conclusion. But it not getting fixed, with the replacement, has us a bit vexed. Community advice above is very helpful to guide us. Dollars spent already are a pinch on the budget 😕.

Referencing hot_rod's feedback above, I can see the possibility of the return side 'allowing' heat to escape to that zone now, too. Working to respond to his point, ASAP.

Thanks again, ALL!!

Big Ed_4

Flow checks will last forever ….

Amateur_In_NH

Thanks for your patience, folks!! Life got in the way yesterday…

Performed hot_rod's recommendation, about middle afternoon:

Conditions: One individual had to take a shower, etc., for work and Zone 1 (downstairs) ran a cycle. Yesterday was a bit chilly. About 10*F or so; negatives with wind chill. Our problem zone's (Zone 2) thermostat was OFF (removed from wall, actually); Zone 2 circulator NOT running.

Results: Zone 1 supply expectedly hot to touch. Zone 2 supply felt even hotter than Zone 1. Returns on both warm but could leave hand on copper. Turned the ball valve under Zone 2's circulator to fully OFF. Approximately 45 minutes later went to check and Zone 2 return was noticeably cooler to the touch!! Zone 2 supply warm but nowhere near what it was prior.

So, a defective, or 'blocked', flochek that's not closing properly, I assume! Does the above indicate that we might need to add a check valve on the return or just get the supply side flochek working properly?

Thanks again for all the help!!! Comments appreciated!!

hot_rod

check the checks first

Amateur_In_NH

https://forum.heatinghelp.com/discussion/comment/1839691#Comment_1839691

Will do, hot_rod. Tech coming back tomorrow, Monday, 2/3. 2pm or so.

Thanks for all the advice!!

GW

for decades I always thought the Taco check was as good as gold. A year ago we had to replace one on a new install—-head scratcher. Maybe there was a bad batch

If it’s used to work with one check, it should continue to work with one check.

However—-we recently had a job where we did a quick boiler swap (different story). The existing “spring check” stayed in place (for the indirect water heater). A month later I send my guy to install a dirt mag scrubber (different story). A few days later homeowner says the water is too hot. Theory is, the spring check failed at this time (vibration) . We replace the spring with a new Taco. Still overheating. We replace it with another new Taco. Still overheating. Friday I had him install a mixing valve in the domestic water side——getting tired of dealing with the ghost flow.

It’s called ghost flow for a reason, sometimes it can defy common sense

Amateur_In_NH

Good info, GW!! Thank you!!

Amateur_In_NH

https://forum.heatinghelp.com/discussion/comment/1839509#Comment_1839509

Big Ed_4, you got me thinking (probably a very dangerous thing, my family warns me, with me 'thinking'… 😁😉). From their specs, it appears the 218 is 3/4 NPT (FWWEBB copy of TACO spec sheet):

Are you suggesting/recommending we ask for a 220, 1", to replace it (with necessary couplers/adapters), if checking/cleaning the new 218 doesn't solve the issue?

Thanks in advance!!!

Can't quite tell for sure, with my old eyes, if the Zone 1 Flo-chek is a 218. With the longer run for Z2, is the larger 220 warranted?

Joe Mattiello

are you sure the pump for that zone is displacing water to the problem zone? Take an amp meter reading, and you should be close to nameplate amps. Call Taco tech support at 401-942-8000 before changing anything else.

Amateur_In_NH

Hi Joe, THANK YOU and to everyone helping us!

Short answer, no, not sure. Can't hear or feel the circulator running for the problem zone (Zone 2, 2nd floor). We'll certainly ask the tech today to take a measurement. He did measure amperage/voltage coming out of the SR502 to ensure the thermostat was not calling. Thermostat face plate has been pulled from wall, during this whole situation (Honeywell digital non-programmable).

Clarifying though, are you saying measure the amp draw on the Circulator itself, while "idle" and while "running"?

Thanks!!