In case of difficulty
If you have difficulty with your thermostat, please try the following suggestions.
Most problems can be corrected quickly and easily.
Display is blank
Heating or
cooling system
does not respond
• Check circuit breaker and reset if necessary.
• Make sure power switch at heating & cooling system is on.
• Make sure furnace door is closed securely.
• Make sure fresh AA alkaline batteries are correctly installed (see
page 14).
• Set system switch to Heat (see page 6). Make sure the temperature is
set higher than the Inside temperature.
• Set system switch to Cool (see page 6). Make sure the temperature is
set lower than the Inside temperature.
• Wait 5 minutes for the system to respond.
RTH4300B Programmable Thermostat