Ghost flow help please

Barley12

I have a weil mclain boiler and I'm experiencing a ghost flow on my first zone. I have been in this house for 13 years and never had an issue before. Coming off the supply side of the boiler I have a manifold with 5 Taco circulating pumps. Zone 1 is master bedroom and zone 5 was added at a later time and is dedicated to hot water tank….was added prior to my purchase of the house. When I jump the thermostat the circ pump kicks on. I have zero voltage at the pump if the stat is not calling for heat. Relay closes and I get 120V at pump when stat calls for heat. After all my circ pumps I have Taco flocheck valves so of course that must be the issue. I have replaced the flocheck valve with a brand new one twice yet the problem persists. The stat is in the off position yet I'm getting constant heat in zone 1. If I close the valve after the circle pump or the valve on the return side at the boiler the flow obviously stops. No other zones experience a ghost flow if the valve to zone 1 is/are closed. Boiler guy check boiler today and all is good. I'm at a lost as to what else it could be. Any ideas??? Thanks!!

Intplm.

Taco flo-check? Some have a small piece of cardboard in the flo-check itself. It is placed there for shipping purposes/protection. Was that piece of cardboard removed before it was installed?

Barley12

Yes I was sure to remove the cardboard piece on both the new valves I tried. I also exercised the valve with the thumb screw on top several times to no avail.

EBEBRATT-Ed

@Barley12 probably a dumb question but is the thumb screw set for auto operation of the flow check?

Pictures of the supply and return manifold may help.

Does that zone heat even if all the zone pumps are off?

I don't know what has change to cause the ghost flow but another flow check on the return may help but I would look for other cause before doing that.

bjohnhy

Can you describe in more detail what issues are going on that points to ghost flow in zone one? Is that zone always overheating despite thermostat call met? Are those radiators at full hot temp despite not calling for heat? Or just barely warm? Is it all the time or only when other specific zones are calling?

Please post some pictures of your set up, boiler, manifold, circulators, zone controller.

Barley12

The master zone is hot at all times…..I have 4 stats throughout the house. If I have all 4 stats in the off position the master zone is still hot. If I pull the relay for the master zone heat is still being produced. The only way to stop the heat to the master is to close a valve in the loop. It makes no sense at all. Regardless of the temp I set on the master stat heat flows non stop. I usually have it set at 64 for sleeping. It was 71 in my room this am. The outside temperature last night was 18.

Barley12

All other zones work properly. When stat calls for heat the circ pumps turn on and heat starts. Once temp is reached the pumps shut off and the pipes cool. The pipe for the master zone is hot 100% of the time…both the supply and the return. The master circ pump never has to come on because heat is always flowing.

Barley12

This is a baseboard set up with oil furnace.

Barley12

Big Ed_4

Open up the flow check and clean the seats , loose teflon and pipe dope can prevent the weight from seating .. Or throw a spring check on the return …

Barley12

The flocheck is brand new….and I have the same results with 2 new flochecks.

hot_rod

the pump on the far right, does it have a check?

You could try turning the valve on the return of the overheating zone and see if it stops the flow.

Too bad there are not iso valves on the pump to check for flow there, when the pump is off.

Big Ed_4

Then add an spring check on the return .. Some times you have to add two ..

hot_rod

with your hand you can maybe feel if flow is reversing and going up the return. That reverse flow even with a working check on the supply is usually a very slow ghost flow condition. So if the supply is cool and the return, several feet from the boiler, is warm or hot it could be reversing.

Odd that it just started, the flo checks are turned CW all the way?

Barley12

flocheck is all the way clockwise. There is water running thru the pump w it off. If I close the loop and let the water/pipes cool and then open the loop the pipe just distal to the circ pump starts to get hot almost immediately…..so I know the water is flowing in the "normal" direction. That also tells me water is flowing thru the pump even though I have the relay pulled and the pump is therefore off. It takes a few minutes for the return pipe to warm after opening the loop.

Barley12

the pump to the far right is dedicated hot water tank and only a 6' run. No check valve on that.

Barley12

thinking about replacing the circ pump w a pump that has a built in Flocheck. It is crazy that this just started happening

bjohnhy

Can you post a couple pics of the inside of your Taco zone control panels? And let us know which one is The zone in question.

If all the thermostats are NOT calling for heat, does the boiler turn off?

I don't see a separate system circulator, is that correct?

bjohnhy

Does your boiler have a built in circulator? What model is that weil mclain boiler?

EBEBRATT-Ed

Shouldn't need to do this but you could put a zone valve on it. Something is going on . Classic sign of a bad flow check but you have replaced it twice.

Barley12

No separate circulator system. The boiler only kicks on when a stat calls for heat or water temp drops below certain temp.

Barley12

the only thing that makes sense is a bad Flocheck but replaced x2

Barley12

image.jpg

Barley12

the relay I'm pointing to is the ghost flow zone. Heat flows wether that relay is plugged in or not

Barley12

the separate switching relay box to the right is dedicated to the hot water tank zone

Barley12

Barley12

PC7060

https://forum.heatinghelp.com/discussion/comment/1881624#Comment_1881624

easier to review pictures if you directly include in post using the image control below.

hot_rod

with power off to all pumps, the ghost flow is not pump related.

Ghost flow can be caused by the warmer water rising, just as the old gravity systems worked.

So keep looking for the path of the hot water. If the pipes continue to stay warm past the flow checks, as far away from the check as you can reach, then the check is suspicious.

Debris in the check is not uncommon after wrenching on old steel pipe.

It the return is hot, some flow is going backwards

Barley12

I believe the return is getting hot once the heated water makes its way all the way through the loop. Hot water is getting past the flow check somehow but I cannot figure out why. The house is 23 years old.

hot_rod

Well, you need to start somewhere? Hot water is moving through the pipes, obviously.

It looks like the relay box on the right is activated based on the lights? Those control boxes do not look to be 23 years old?

Did you try turning the power off, This assures ALL pumps are powered down.

If you continue to feel hot pipes after 20 minutes or so with pumps confirmed off…

Disassembling the flow check would be my first step. Although it looks like a partial drain down will be required, then a refill and purge.

If it has worked in the past 23 years, nothing has changed in the piping or control? I would not suspect that you are getting reverse flow.

So back to the flow check as the primary suspect.

wcs5050

one of those 4 LH taco circs (2nd from left) has been replaced, and is the new style volute that will receive a check cartridge on its outlet… easy fix for at least one zone.

I’ve had weird ghost flow issues with flo-checks… once added sentinel water chem stabilizer, and one zone developed g-flow where it was fine before.. added 2nd flo-check and that stopped it. I attributed to the chem changing the system water density, but who knows.

bjohnhy

@Barley12 as hotrod has suggested, you have to determine if the hot water entering that zone is coming from the return side or from the supply side.

Some of your descriptions make it sound like it's from the supply side.

If you determine it's reverse flow from the return, you can add a spring check on the return for that zone.

If the heat is coming from the supply side (thermosiphoning effect, I cannot see how else it could be from supply side unless the other circulators are installed backwards), I would add another check valve to supply side with a higher cracking pressure than what you have (0.75 to 1 psi?)

Temporary fix is to partially close down that valve above that zone pump. But that's just a bandaid.

Barley12

The flow is definitely coming from the supply side. When I open the loop I can follow the hot water on the supply side as it travels down normal route. The circulator pump second from the left is within the past month as the old pump was toast

Barley12

the supply side pipes get hot immediately and it takes several minutes for it to make the loop and return to the boiler so the return pipe stays cool for several minutes

Barley12

Would the new taco circulator pump which is second from the left somehow be contributing to the ghost flow on zone one which is the zone all the way to the left?

Barley12

I discovered the ghost flow after replacing the Bad circ pump. While I was trying to purge air from the zone with new pump I found the master zone to be hot even though the boiler was off. I am not sure if the ghost flow was present prior to changing the circulator pump second from the left

hot_rod

those pumps with those Flo checks should work just fine. Weighted Flo checks have been around, used successfully since the 1950, or 60s.

If you re 100% sure they are all in the closed position, thumb screw turned CW all the way, then opening them up for inspection is suggested. I see isolation valves just beyond those checks, so it may not be a big job.

Open them all, look for rust and corrosion under the weight.

Barley12

the Flocheck is brand new. I have replaced it twice in the last 10 days w a brand new Flocheck

Barley12

I thought by some chance maybe the first flo check valve I bought and installed was faulty though I would imagine the chances are low. The second brand new Flocheck yielded same result.

hot_rod

is the screw on top turned down, clockwise all the way?
Check Yes or no?😉