Taco exp switching relay

Wayco Wayne

board, and a PC705-2 injection mixing control for a radiant floor. Their directions are very incomplete. Does the control system need a tstat in the space? What does the Master slave switch do? Are the other zones, (indirect WH and radiators) on the board affected by the injection control? Once I do the first one I'm sure I'll be fine.

Alan(CaliforniaRadiant)Forbes

Taco

Hi Wayne!

I've only used the PC 700 boiler reset control and that was a while ago. As you can tell, it's a tekmar product, but a lot easier to use and set up.

My guess is that you do need a t-stat. As far as radiators and DHW, you'll have to pull those off separately off your primary loop, but you will still get DHW priority if you set up your ZVC for it.

The Master/Slave switch on your EXP zone valve controller is used when there is more that one controller; lets say you have 10 zones and you are using two ZVC406-EXP's and you plug the PC705 into one of them; that one will become the master and the other one the slave. You'll want to do DHW priority off your "master" as well. If you only have one ZVC, just switch it to "master".

David Sweet at Taco (401)942-8000 x282 is very helpful. Taco also put out a very easy to use wiring booklet called "Taco Zone Controls Wiring Guide"; there's a section called, Zone Valve Controls - Connected to Reset Controls (PC700, 702 & 705) on pages 32-39.

If you want me to FAX the pages to you, call me at (510)452-2844 and leave your FAX number on my machine; I'm just leaving the office for awhile.

Best wishes,

Alan Forbes

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