line voltage to dry contact

Paulypfunk

We are switching out a pretty simple tank system for a mod con boiler.  The old system was a 65 gal hot water heater, one zone with one circulator and six hydronic wall blower units.  The house has five line voltage thermostats.  When there is a call for heat from any of the tstats it sends line voltage to the circ pump. 

We now have a TT prestige excellence.  I need to send power to the circ pump on a call for heat and I need a way to convert that 120V call for heat across a transformer to a dry contact into the TT on the boiler control board.  It is my understanding that a simple 120/24v transformer wont work.  The instructions state that the call for heat contact must be dry and have no voltage present.

Can someone suggest an isolated relay that should be readily available?



thx

Paul Stalwart

SWEI

You need a simple pilot relay

Like one of these http://www.functionaldevices.com/building-automation/display.php?model=RIBU1C