Ghost Flow issues?

[dsungaila]

Good afternoon folks!

A little stumped - my zone valves that were 20 years old crapped out and I ended up replacing all of them with circulator pumps. I installed the pumps (see pics) to pull away froim the boiler into the zone. Each pump is on a thermostat, with Zone 1 being the biggest one (main living area). I have also installed a flow valve on each of the returns.

Issue is - whenever any of the pumps is on - all of the zones flow, even with the flow valves. I turned off the boiler circulator pump (took off the wires) and there was no flow present whatsoever. As if the boiler was not allowing any flow. Boiler is about 20 years old and I don't think it has load activated flow valve (if that is even a thing)?

Question is - what am I doing wrong? Or what can I try and change to make it work right for each zone?

 

[Fitter30]

Nice piping and wiring. Taco manual doesn't spec a position but being a check that rides on a shaft think it getting bound up and should be piped on a horizontal line stem up.

 

[Sponsor]

 

[dsungaila]

Nice piping and wiring. Taco manual doesn't spec a position but being a check that rides on a shaft think it getting bound up and should be piped on a horizontal line stem up.

Thanks!

As to the flow valve - Taco manual (PN 218) does say it can be mounted vertical. Which I hope is true...

 

[Fitter30]

Called tech support 401 942 8000 talked with them. Flo chek has to be piped in the horizontal plane stem up. Just like their piping diagram. Also ask them about why there was wasn't anything written about this. Didn't have a answer.

 

[John Gayewski]

How far apart are those tees? They look like they are too far apart. A primary secondary system will need the tees spaced very close. The pump's suction needs is pulling from your primary loop only (or should be) if it's easy for the pump to grab it from one of the other zones it will.

If those pumps have built in check valves they are probably bad. If they don't you need to add some check valves so the water can't drift from neighboring zones.

 

[dsungaila]

Called tech support 401 942 8000 talked with them. Flo chek has to be piped in the horizontal plane stem up. Just like their piping diagram. Also ask them about why there was wasn't anything written about this. Didn't have a answer.

Ugh - I was really hoping that was not the case. Thank you for making the call!! At this point - I am just going to pipe these horizontally. It'll ruin my pipe aesthetics ;(

How far apart are those tees? They look like they are too far apart. A primary secondary system will need the tees spaced very close. The pump's suction needs is pulling from your primary loop only (or should be) if it's easy for the pump to grab it from one of the other zones it will.

If those pumps have built in check valves they are probably bad. If they don't you need to add some check valves so the water can't drift from neighboring zones.

The tees are roughly 12" apart. It is all on the same system, and I agree with your point. The flow valves should take care of the issue though?

As to pump check valves - they are brand new Grundfos pumps with check valves. Would be surprised if 4 of them are faulty. What I think is happening is that the boiler circulator is pulling through from all the zones, as the flow checks are apparently not installed correctly.

 

[John Gayewski]

Ugh - I was really hoping that was not the case. Thank you for making the call!! At this point - I am just going to pipe these horizontally. It'll ruin my pipe aesthetics ;(


The tees are roughly 12" apart. It is all on the same system, and I agree with your point. The flow valves should take care of the issue though?

As to pump check valves - they are brand new Grundfos pumps with check valves. Would be surprised if 4 of them are faulty. What I think is happening is that the boiler circulator is pulling through from all the zones, as the flow checks are apparently not installed correctly.

Yes that means the tees are too far apart. And 12" is way more than specified for that installation.

 

[dsungaila]

Yes that means the tees are too far apart. And 12" is way more than specified for that installation.

Well - it is what it is right now. Need to figure out how to fix it without taking everything apart.

 

[Fitter30]

Mount them high its not like there big service item. 90° out from wall, valve and 90° back. 4 - 90s°. Only one solder joint high everything else on a bench

 

[dsungaila]

Mount them high its not like there big service item. 90° out from wall, valve and 90° back. 4 - 90s°. Only one solder joint high everything else on a bench

Yup - that is what I am thinking. I'll have to see if I have enough pipe, as otherwise I'll just mount them horizontally in their current spot. Thank you for the suggestions!

 

[John Gayewski]

You'd need a perfectly sized circulator that can only pump the primary loop.

That's gonna be a tough balancing act as you'll also need the correct flow rate.

You could experimentally choke down the primary loop on the supply side with a ball valve ( that you already have installed hopefully). Just to see if you can increase the resistance in the primary Loop enough to discourage flow in any of the secondary loops. This could depend highly on where you circulator is located.

 

[John Gayewski]

I just looked at your picture again. The pump being on the return side isn't helping the ghost flow situation here. If I was gonna experiment with choking the primary loop I'd concentrate on the one before the air seperater.

 

[dsungaila]

Thank you for the suggestions!

Ended up properly installing the flow valves - they are now horizontal. Followed that with partially closing off the return valves - everything seems to work as intended!

 

[Fitter30]

Great glad it worked out