I am trying to replace a manual with programmable thermostat that is missing emergency heat (E) terminal. There are bits and pieces of information I have gathered but am still not clear.

Can I leave off (E)?

Manual thermostat (th3210d1004) terminals:

E|AUX|Y|G|O|L|R|B|C where L,B are not used

Programmable thermostat (TX1500E) terminals:


The plan is to wire: R->RH,RC

E->not used

AUX->W ?

All the other letters are matched. Is that correct?

1 Answer 1


Your Lux TX1500E thermostat is not made to be used with a Heat Pump system with emergency heat, so it can't be used in your installation. Lux has an updated model, TX1500U that is made for "heat pumps with up to 2-stage heat/1 stage cool".

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