RT510RF : Thermostat Setup – Dip Switch Settings (1.4.1) .
Thermostat Dip Switches :
On the back of the thermostat there are two small dip switches. One is for selecting SPAN or ITLC and the other allows you to choose between Radiators or Electric Heaters when ITLC has been selected.
Dip switch positions & algorithms :
The dip switches select the thermostat’s control algorithm. There are 3 possible algorithms: SPAN, 6CPH (Rad) or 9CPH (Elec). Treat the “On” label as the up position and the numbers 1 and 2 as the down position.
For all plug-in boiler receiver applications ensure Switch 1 is set to RAD.