Taco PC700

James Day_2

Hey guys, 

On a taco pc700 with a sr503exp,  on a call for domestic hot water will the boiler high fire for domestic or will it run off the reset curve on the pc700?



Thanks

Alan (California Radiant) Forbes

Good question

The only mention of DHW in the instructions is when they say that the boiler will turn on when there is a call from the priority zone and the outdoor temperature is above WWSD.



Does someone have a solution?

Gary Jansen_4

It will work

On a call for domestic water (with priority switch set to on), the reset of the pc700 is ignored and the boiler will go to high fire. When priority is satisfied, the reset curve will then run boiler on a reset curve in the 700. All other heating zones are locked out and can't run when the last zone on the board (priority zone) is calling. You will have to be a little careful because when priority is done you will have some pretty hot water left in the boiler, and it can go out to your heating zones. 

Alan (California Radiant) Forbes

Post-Purge

Thanks, Gary.  That clears it up.



To cleanse the system of high temperature water, you can add a PC600 Post-Purge Timer Plug-In card:



http://www.taco-hvac.com/en/products/PC600+Post+Purge+Timer+Plug-In+Card/products.html?current_category=146

James Day_2

Thanks

Alan and Gary,     Thanks.  I do know about all the plug in cards.  I just couldn't find anywhere in taco's literature about DHW.      Thanks, again