thermostat for gas heater!
 

Hello guys! I have to replace a thermostat for a gas heater unit (Cozy) I called company but they do not have the original thermostat in stock the unit is too old. But the technician told me that I could use any 24v thermostat and I have to leave the thermiser disconnected! the old thermostat has 4 wires White-Red-Yellow-Yellow. for what I understood is:

A) in the new thermostat connect the White wire to the W
B) in the new thermostat connect the Red wire to the R
C) leave disconnected the two yellow wires from heater and disconnect the wires from new thermostat "thermiser" ?

Is that all right?
can anyone help me with wiring please.