How to wire Primary and Secondary Pumps w/Zone valves

Slow-Jim

Hello,

I am installing a new Munchkin T80M (wall mount) to run baseboard heat. Per the Preferred Piping schematic in the Munchkin manual (see the munchkin PDF attachment-ignore the DHW) I am using a Primary/Secondary pumping setup with two Taco 007's and two Honywell zone valves (4 wire).

I am wondering how to wire up my two zone thermostats to control the two zone valves in addition to the two pumps and boiler.

Also, I read Dan's article on Understanding Primary-Secondary Pumping (April 5, 2000) and it seems a bit different from the Munchkin schematic. Per this article I have modified the munchkin schematic (see hydronic_piping attachment) and added a full port ball valve between my closely spaced tees, put the expansion tank on the primary return upstream of the Primary pump, and I added the water feed to the Primary return as well.

Is the point of no pressure change still important when using pressure regulators on the water feed? I have been told to screw my expansion tank directly to my air scoop without a water feed attachment.

Any info provided is much appreciated.

Cheers,
Jim

Dan Peel

More info on piping

Try www.hydronicpros.com , in the technical area. For wiring look at Taco's zone valve controllers www.taco-hvac.com Enjoy....Dan

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"

hr

Not so fast, Jim

For ease of wiring consider the Taco Zone Controls. They will provide the 24 V for the zone valves, provide indicator lights, and have additional contacts to switch the system pump. I buy the Taco with one more relay than zone vales for expansion or in the event one relay goes bad,
The boiler pump will be powered from the relay provided inside the Munchkin.

The PDF drawing would be my choice. Low mass boilers like the pump pushing into the boiler. Also you are pumping zway from the PONC by installing the expansion tank in the loop as shown. Really no need for the ball valve between the closely spaced tees. It just increases the pressure drop. Some radiant panels use this valve to speed purging. not really an issue in your case.

Connect the fill valve near the PONC (expansion tank connection). It doesn't necessarly have to be at the exact tee connection that the expansion tank is. Generally this is a convient spot, however.

Stick with drawing two, for a trouble free installation.

hot rod

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"

Slow-Jim

Thanks for the replies!

Hot Rod, OK so I will stick with the Munchkin schematic.

I'll get a Taco ZVC for 3 zones. So my understanding is that this unit will isolate the two thermostats/zone valve combos from each other, so that one zone won't trigger the other zone due to them both using the same terminals (1 & 2) on the Secondary pump.

So with the ZVC... each thermostat/zone valve combo will have its own terminals, and the ZVC will relay their calls to the secondary pump and then the pump will call the boiler. The boiler controller will pass the call to the primary pump.

I wish the Taco 00 series pumps came with more wiring examples.

Again, thanks for your help.

slow-jim

hr

correct a mundo

The control will come with a good, readable, understandable wiring diagram.

Taco has an excellent guide for wiring all of their controls. If you want a good understanding and excellent schematics get a hold of one.

hot rod

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"