Honeywell Prestige Thx9000

[Halifax_Kevin]

I have a Honeywell honeywell prestige thx9000 thermostat which has a cr2032 battery. It is wired with the IAQ interface and uses the R and C wires at the thermostat. It works great without inserting the CR2032 battery. However, when I insert the battery (which is suspose to ensure settings are kept in the event of a power outtage) the thermostat screen will not turn on. All I see is black. I've used a few CR2032 batteries to eliminate the possibility of a low power battery. All the rest of the components work perfect including the wireless outdoor sensor and the remote handheld thermostat control.

Any thoughts? Thanks in advance.

[hearthman]

skidoox800, This is the Ask Our Pro's forum. In order to post advice here, you must have verified qualifications and have been approved by the AOP Committee. Please see my signature line for links to register and review the AOP Forum Rules. Thank you. Your post will now be deleted.