7
OPERATIONAL INFORMATION

Five--minute Compressor Timeguard

The cycletimer limits the numberof times the heating or cooling equipmentcan be energized in one hour.If option 1 is set to a value of 1 or
2, the equipmentwill be allowed toenergize up to six timesper hour. If option 1s set to 3 or greater,then the equipmentwill be allowed to
energizeup to four times per hour.This timer is defeated for1 cycle when the desired temperature is manually changed.It can also be
defeatedfor 1 cycle by simultaneouslypressing theFAN button and the INCREASE TEMPERATUREbutton.

Cycle Timer

This timer prevents the start of a heating or cooling cycle until at least 15 minutes after the last start of the same cycle. Its functio n is to assure
that equipment is not cycled more than 4 times per hr. This timer is defeated fo r 1 cycle when the desired temperature is manually ch anged. It
canalso be defeated for 1 cycleby simultaneously pressingthe FAN modebutton and the INCREASE TEMPERATUREbutton.

Staging Timer

In multistage heating or cooling, this timer prevents any h igher stage from turning on until the precedin g stage has been on for 15 minutes.
This timer is defeated if the temperature error is greater th an 5_F/3_C (usuallydue to a large change in desiredtemperature).

Three--minute Minimum On Time

In normaloperation, when a stage turnson, it will not turn off for a minimum of 3 minutes.

Heat/Cool Setpoints (Desired Temperatures)

A minimum difference of 2_is enforced betweenheating and cooling setpoints.This is done by allowingone setting to “push” the other, to
maintain this difference.

Auto Changeover

When the auto changeovermode is selected, a changefrom heat to cool (or vice versa) will not occur untilan opposite mode demand has
existedfor 20 minutes. If the setpointis changed, the 20 minute requirementis deleted. Auto mode may be disabled.

Emergency Heat Mode

When thermostat is configured as a heat pump and emergen cy heat mode is selected, allY sig nals arelo cked out and W becomes energized
upon a callfor heat.

Heat On and Cool On Icons

When a heatingor cooling demand exists, the HEAT ON or COOL ON icon will either remainon or flash. If flashing, the equipmentis
temporarilyprevented fromturning on by one of the timers(see above). Whilethe icon remains on withoutflashing, the equipmentis on.

Power On Check

When AC poweris first applied, allsegments of the displayare turned on for a few seconds.Following this, the temperaturedisplayindicates
themodel/configuration viathe following 2 digit code:AC—1 --speed air conditioner,HP—1--speedheat pump.

Error Codes

-- -- — If the thermostatcannot properly read room temperature,the display willindicate ---- (2 dashes) and all outputs(except the fan if on)
willturn off. This is to prevent operationof the equipment if the thermostathas failed.
E2 — Ifthe AC line voltage dropsbelow a minimum (brownout)level, all outputsare turned offand the display indicatesE2. This condition
will remain for 15 sec after proper line voltage is restored. If the AC line vo ltage disappears completely, the display will immediately go
blank.
Thermostat Troubleshooting
SYMPTOM WHAT TO CHECK
BlankL CD Checkfor 24vac between R and C at terminal connectionsor battery.
“ --- --- ” (2 d a sh e s ) on t em p e r a t u r e di s p l a y Temperaturesensor reading outof range. Check sensor for damage. If
recyclingpower does not clear display,thermostat shouldbe replaced.
“E2” on temperature display
Brownout condition or too low of voltage to thermostat. Double check
wiring and check for 24vac between R and C. E2 will clear 15 sec after
proper voltage is restored.
“SERVICE FILTER”on temperature d isplay
Aftertheselectednumberofhourofbloweroperation“FILTER”willdisplay
on LCD. This is to remind the homeowner to “ch eck” the filter. Press
RESET FILTER button to clear display and reset timer to 0.
Cooling will not come on
SelectCOOL mode. Set desired temperatureto 10˚F below room temper-
ature. Simultaneouslypress FAN and INCREASE TEMPERATURE buttons
to defeat timers.Check for CO OL ON icon and 24vac at Y (first---stage)
terminal.If present, thermostat is OK and problem iswith equipment or
wiring. If not present, replacethermostat.
Heating will not come on
SelectHEAT mode. Set desiredtemperature to 10˚F/6˚C above room
temperature. Simultaneouslypress FAN and INCREASE TEMPERATURE
buttonsto defeat timers. Check for HEAT ON and 24vac at Y (first --- stage)
terminal(with heat p ump) or W (with air conditioner) terminal.If present,
thermostatis OK and problemis with equipment or wiring. Ifnot present,
replace thermostat.
T2SN