Resideo TH1100DV1000 Thermostat 321702-401 the Spirax Sarco 13WS ensures

the Spirax Sarco 13WS ensures optimal circulation by removing air pockets at system high points

Using a blade with a steeper pitch can increase the amperage draw beyond the motor's nameplate rating

While universal valves exist

2 series pumps

Does this unit provide a fail-safe position on power loss

Resideo TH1100DV1000 Thermostat 321702-401 the Spirax Sarco 13WS ensuresThe Resideo TH1100DV1000 Thermostat, part of the Honeywell Home PRO 1000 Series, is a vertically oriented, non programmable control tailored for 1 Stage Heat Only applications. Engineered for field reliability, this unit integrates seamlessly with 24VAC conventional gas or oil systems as well as 750mV millivolt floor and wall furnaces. Its dual powered design allows for operation via 2 AA batteries or a direct hardwired connection to the C wire. For