Weil Mclain GV-5 Baseboard Flow

dvizz

I recently replaced 4 Honeywell Zone valves with 4 Flow Control valves to allow me to use a Taco -SR506 Priority Zone controller. The Taco replaced 4 Furnas contactors that would send the signal to the zone valves and energize the zone circulator pumps. The Taco is working properly as my DHW indirect is prioritized and not allow the zone circulator pumps to run when the room thermostats are calling for heat. The system previously allowed the pumps to run even as the indirect was calling for hot water from the boiler. The boiler uses a internal circulator to feed water to the Indirect. The internal circulator also runs whenever a baseboard zones calls for heat. The system is piped with 4 Circulator pumps each being controlled by 4 thermostats.
What I'm feeling is the water is flowing through all the zones even as the respective circulator pump is not energized. The piping coming from the boiler is a 1" riser to the ceiling and nineties, supplying the individual zones There is a 1" riser returning in parallel to the boiler. How do I prevent the flow reaching the zones that is not calling?

Tim McElwain

It sounds like the system is in need of revamping and rewiring You have zone valves and circulators not set up in sequence. You need to get a heating professional to take a look at it. Are there two circulators inside the boiler? If so one is a system circulator the other is a bypass circulator.

Ironman

Are you saying that you replaced 4 ZVs with 4 circulators? If so, you must have a flow check in each zone or circ.

Some pics would help.

lchmb

you need to pipe this boiler primary/secondary...

Paul48

Yes.....It needs to be P/S, and the primary loop should be 1 1/4".

dvizz

I took some photos of my sysytem. The photo of the Taco SR-506 was what I installed to replace 4 Furnas contactors (IMG 5041) used to control Circulators and zone valves. I replaced the zone valves with Taco flow control valves which were installed at the ZV locations, the return side of the baseboard loops. The SR506 is working as expected; that is prioritizing the indirect and turning off the baseboard thermostat control untill the indirect is satisfied. What is happening although not too disappointing is baseboard flow is entering all zones when there is a single thermostat calling for heat. The internal WMclain circulator runs whenever there is a call for heat through the room t. stats or the indirect aquastat.
I am looking for a piping alteration to remedy this.
IMG 0541 is what the controls looked like before I installed the Taco SR-506.
IMG 0585 shows the risers for supply and return to the baseboard piping.
Will incorporating the piping schematic I received from WMclain :(gv primary-secondary) cause the flow to only pass through the one circ. pump running even as the internal pump is running?
Will putting a 1" line connecting the supply and return headers provide the flow as designed?

dvizz

I'll post some photos and illustrations.
DSC02019 is what the controls looked like before IMG 0578 was installed.
IMG 0579 shws the flow control installed where previously Honeywell zone valve was located. There are 4 sepaerate zones with this configeration.
IMG 0580 shows the indirect piping going to the WM Ultra 30 DHW tank. There is a 3 way valve that when energized closes flow to the baseboard supply riser and diverts it to the indirect untill the aquastat is satisfied. Before I installed the SR-506 the baseboard circulators and zone valves would operate even as the flow was stopped going to them. The SR-506 has prioritized the Indiret so I'm pleased with that aspect. The internal WMclain circulator is pushing water through all zones even as only one circulator is running from thermostat demand. That is my issue.
Will bridging the risers across the supply and return 1" piping stop the flow from reaching zones that are not calling for flow and only allow flow to the zones calling as shown in illustration 0588? There is a 8" spread between the two risers.

Ironman

Your photos are too disjointed to tell the entire piping scheme. I'm trying to piece everything together from them and your description.

Are you pumping the boiler through a set of closely spaced Tees as shown in the diagram? If not, your zones are in series with the boiler circ and that's what's causing the unwanted flow. You have to pipe it primary/secondary as shown in the diagram. Is that what you're referring to when you say "bridging the risers"?

dvizz

What I am trying to accomplish is pipe the system to incorporate closley space tee's. The supply and return risers 90 to and from the baseboard zones. Is the location of the close space tee's at the 90's.

Paul48

Have you looked at the recommended piping diagrams in the manual?

Ironman

Change this:


To look like this:

dvizz

I've seen that configuration on the WeilMclain web site "Part number 550 -141-856/0703" I don't understand how the flow would be changed by piping in the Closed space T..

lchmb

leave it that it's needed in order to solve the issue your having..it separates the two circulators so one cant cause flow through the other... can you show where those two pipes tie in on the other end?

dvizz

The supply line on the right ends by reducing to 3'4" from 1" to feed the 3 beedroom baseboards at the end of the house. The return 3/4" line continues to tie into the return 1" line on the left.
Can I move the return line to come out and up vertically from the boiler as I drew up on 0595JPG. The broken lines depict the existing piping as shown on 0592JPG. Will the 4" seperation between the supply and return be enough for the flow to only be pulled when the baseboard pump is running even as the boiler pump is running in series.

Ironman

Look at the necessary spacing in the diagram. It does NOT matter which direction the bull of the Tees points, but all else does.

dvizz

It looks like I need to have the supply line on my boiler which is the one on the right a min. of 8" to the Tee which would replace the elbow. The other side on the return would measure 4" just as I sketched it on 0597

Ironman

I think you'll find it easier to extend the overhead supply and return lines to the left and then place closely spaced Tees in them like I drew them. Your drawing looks correct, just more work.

dvizz

One more question: I have a 3 way that diverts flow to the indirect when the aquastat calls and opens to the baseboard supply for thermostat heat calls. The indirect is priority now that I installed the SR 506.The line coming out of the boiler reduces to 3/4" from 1" and is 3/4" on the feed and return back to the boiler. I would like to increase the size to 1" to shorten the amt. of time it's taking for the indirect to reach aquastat temp. as there would be more btu's added to the indirect. Could I remove the 3 way and just have a zone valve on the supply or return side that would act as the 3 way is working now?

Ironman

No, not unless you put a zone valve on both the indirect and the pipes going to the Tees in the house loop. I can see no rationale for that.

There's another way to re-arrange the piping for p/s and add a circ for the indirect. But again, a lot more work and materials.

If the indirect is close by the boiler, increasing the piping to 1" probably won't make that much of an improvement.

dvizz

"I think you'll find it easier to extend the overhead supply and return lines to the left and then place closely spaced Tees in them like I drew them. Your drawing looks correct, just more work.
Bob Boan"
I'm not good at visualizing your description of the piping change as you describe and drew it.
Could you provide me a more detailed illustration of your concept drawing?
Thanks

HVACNUT

Cut it all out and start over using Weil Mclain specs. And for Christ's sake, get the circs and zone board out of the ceiling.

dvizz

I'm not that ambitious.

dvizz

Ever since I installed the 4 Taco flow check valves at the end of each baseboard loop where the zone valves were previously located I'm experiencing hammering in the loops. The system is not air bound as I bled the system and have a PV Supervent air eliminator in line. The system had no water hammer issues when it ran with the zone valves in line. The reson I removed and replaced the zone valves with flow control valves was to allow the installation of a Taco SR 506 controller so the indirect would be prioritized. That aspect is working well. The hammering occurs in the morning when the system is recovering from set-back thermostat settings on 2 thermostats, from 65 deg. to 69 deg. My baseboard water temp is set at 180 deg. The hammering is coming from various areas sub floor, I have a Rancher and have tried loosing some of the copper piping clamps supporting the piping as it travels to the baeboards.