Honeywell RTH221B Manual

Your Honeywell RTH221B thermostat has a feature that helps prevent damage to the compressor of your air conditioning system.Because damage can occur if the compressor is restarted too soon after shutdown, this feature forces the compressor to wait five minutes before restarting.During the wait time, the message Cool On flashes on the screen.When the safe wait time has elapsed, the message stops flashing and the compressor turns on.Press the Run button to follow the programmed schedule. You can have up to four periods in one day. Each period can be programmed with a different temperature setting.

To program a period, you need to set its start time and its two temperature settings (one when the thermostat is in cooling mode and another one when it is in heating mode).The same period and settings are repeated every day.For maximum energy savings without sacrificing comfort, you can program the schedule such that the temperature is at an economical level when you sleep or are away during the day and at a comfortable level when you are awake and at home.

Set the switch of the system shutdown before removing the batteries. Otherwise, the system of heating / cooling could remain activated even when the batteries are removed. Install two fresh AAA batteries when Lo Batt (low batteries) flashes on the display. The icon appears for 60 days before exhausting the battery. Replace the batteries once a year or when it fails for more than one month. Most of the settings are stored in non-volatile memory (permanent). You should only set the clock if the thermostat does not have batteries.

Download Honeywell RTH221B Manual

Tweet