Wiring my boiler

jswampler

So I just piped in this crazy boiler system (crazy for me).  I have a Viessman 200-W powering 3 radiator zones and a 55 gal. indirect DHW tank.  5 grundfos circulator pumps, a low-loss header, a taco 4-zone relay, a taco 1 zone relay, Uponor pex piping, with uponor manifolds.  I have no idea how best to wire this system.  Can anyone walk me through this or point me to something that can help me.  The wiring diagrams accompanied with the components add to the confusion.  I just need a helping hand.  I thank you in advance.

Alan (California Radiant) Forbes

Wiring

On a call for heat from any one of your thermostats, the Taco SR504 would turn on a pump and close an end switch to turn on your boiler.  So wire the thermostats, the 3 zone pumps and a boiler end switch to the SR504.  Wire the DHW pump and the primary pump directly to the boiler so that when there's a call for heat it will turn on the primary pump and on a DHW call, it will only turn on the DHW pump.

Ironman

One Other Thing...

Not anything major. If you want your zone pumps to de-energize during a DHW call, then do this:



1. Remove the factory jumper between "ZR and ZC" on the Taco SR504.



2. Connect the hot wire feeding the boiler primary pump also to "ZC" in the Taco SR504.



3. Set the "Priority Zone" switch to "Off" in the SR504.



The "X  X" terminals on the SR504 are the end switch that connects to the boiler's thermostat terminals (24V).



Even if you choose not to do this, there won't be any heat transfer to the zones during a DHW call because the primary pump has stopped, the zone pumps will just continue to circulate in the secondary loops.