Thermostat How-To
How to Program and Use the Prostat+ PSP4273RT Thermostat
The Prostat+ PSP4273RT is a 4.3" touchscreen thermostat with built-in Wi-Fi, up to four heat and two cool stages, a 7-day schedule, and built-in humidity control with a programmable AUX output. This guide covers programming a schedule, setting up humidity control, and day-to-day use. If it isn’t mounted and wired yet, that’s a job for a licensed technician.
At a Glance
4 periods a day
Schedule
7-day touchscreen programming: Morning, Day, Evening and Night periods, set by day or day group.
4 Heat / 2 Cool
Compatible systems
Conventional or heat pump systems with up to 4 heat and 2 cool stages; dual-fuel capable.
Built-in
Wi-Fi
2.4GHz connectivity for remote access and weather through the Skyport web portal and mobile app.
Humidification & dehumidification
Extras
Built-in humidity control with reheat, a programmable AUX output, and Hi/Lo humidity email alerts.
Step-by-Step: Programming Your Schedule
This covers programming the thermostat’s touchscreen itself. Setting it up on the Skyport web portal for remote access is a separate, optional step.
Step 1
Open the Schedule menu
Tap Menu on the home screen, then tap Schedule and choose Edit My Schedule.
Step 2
Choose which days to program
Tap to select one or more days as a group (for example, all five weekdays together), then tap NEXT.
Step 3
Set each time period
Choose Morning, Day, Evening or Night, then set its start time and heat and cool setpoints. Uncheck any period you don’t want running that day.
Step 4
Repeat for the rest
Tap DONE after each period, then repeat Step 3 for the remaining periods. Program a separate day group for weekends if your routine is different then.
Step 5
Review and save
Check what you’ve set, then tap SAVE to put the new schedule into effect.
Setting Up Humidity Control
Humidity control only works once the AUX output is assigned to it, and the humidifier or dehumidifier is wired to that terminal — that wiring is a job for a licensed technician. Once it’s set up, here’s how the settings work.
Set the AUX output usage
Go to Menu > AUX Output Settings and set AUX Output Usage to Humidification or Dehumidification (it can also be set to run a 3rd or 4th heat stage instead). Humidity settings only take effect once this is set correctly.
Set your humidify target
Go to Menu > Humidity > Humidification Settings and set a humidify setpoint between 0% and 60% RH for the heating season.
Set your dehumidify target
Go to Menu > Humidity > Dehumidification Settings and set a dehumidify setpoint between 25% and 99% RH. You can also turn on Run A/C to Dehumidify and Reheat here.
Turn on Reheat if rooms feel cold
With Reheat enabled, the system adds a little heat back in while dehumidifying so the house doesn’t feel clammy or over-cooled. Maximum Overcool limits how far it will cool past your setpoint to pull out moisture.
Daily-Use Features
Manual temperature changes
Tap WARMER or COOLER to adjust the setpoint any time. In Auto mode both setpoints move together; switch to Heat or Cool mode first to adjust just one.
Mode and fan control
Tap the Mode icon to cycle through Heat, Cool, Auto or Off. The Fan button toggles FAN ON (runs constantly, even in Off mode) or FAN AUTO.
Home/Away switching
Tap the Home/Away button on the home screen for a quick occupancy change without setting up a full vacation schedule.
Vacation scheduling
Go to Menu > Vacation/Away > Set Vacation Schedule to enter a start and return date/time and the mode and setpoints to use while you’re gone.
Indoor humidity at a glance
The home screen and drop-down dashboard show the current indoor humidity reading alongside temperature, weather, equipment runtimes and alerts.
Email alerts and service reminders
Once it’s connected to Wi-Fi, it can email you about Hi/Lo Humidity, Supply Air issues, Hi/Lo Temp swings, and when a service or filter reminder is due — a handy early warning for a humidifier or dehumidifier that needs attention.
Tips for Best Use
- Use day-group selection to set up a weekday schedule once, then program weekends separately if your routine differs on those days.
- If the indoor humidity reading looks off, check Menu > Humidity for a calibration offset (−20% to +20% RH) before assuming the sensor is bad.
- Turn on Reheat for dehumidification if rooms start to feel clammy or over-cooled — it adds a touch of heat back in while pulling out moisture.
- Turn on Auto Screenlock (Menu > Security) with a passcode in households with curious kids or in a rental property, and write the passcode down somewhere safe.
- Leave Smart Recovery on — it starts the system early enough that you’re already at your setpoint when a scheduled period begins, instead of just starting toward it then.
Common Mistakes to Avoid
- Setting a humidify or dehumidify target without first setting AUX Output Usage to Humidification or Dehumidification — the setpoints do nothing until that’s assigned.
- Adjusting Auto mode setpoints together when you meant to set heat and cool separately — switch to Heat or Cool mode first, adjust, then return to Auto.
- Leaving Reheat off during dehumidification season and then wondering why the house feels chilly and damp.
- Turning on Auto Screenlock without writing down the passcode first.
Troubleshooting
- Blank or dim touchscreen. Check your breaker for the HVAC system first, since this model is low-voltage powered rather than battery-powered.
- Humidity doesn’t seem to be controlled. Confirm AUX Output Usage is set to Humidification or Dehumidification under Menu > AUX Output Settings, and that the humidifier or dehumidifier is actually wired to that terminal.
- Won’t connect to Wi-Fi. Confirm your network is 2.4GHz, since that’s what this thermostat supports, and check Menu > Wi-Fi > Wi-Fi Status for signal strength and connection state.
- Schedule doesn’t seem to be running. Confirm the right days and time periods are enabled (checked) under Edit My Schedule, and that you saved after making changes.
Still stuck? Call (847) 224-2420.
Prostat+ PSP4273RT Questions
What’s different about this model versus the Prostat+ PSP4272RT?
They share the same touchscreen, Wi-Fi, 7-day schedule and 4 heat/2 cool staging. The PSP4273RT adds built-in humidification and dehumidification with reheat, a programmable AUX output, and Hi/Lo humidity email alerts, which the PSP4272RT doesn’t have.
Does it need special wiring for humidity control?
Yes, the humidifier or dehumidifier has to be wired to the AUX terminal. That’s an installation question for your HVAC system’s low-voltage wiring, which we recommend leaving to a licensed technician.
Can I use the AUX output for both a 3rd heat stage and humidity control?
No, AUX Output Usage is one setting at a time — it can be assigned to a heat stage, humidification, or dehumidification, but not more than one at once.
What if it isn’t mounted yet?
This guide only covers programming and day-to-day use. Mounting and wiring it involves your HVAC system’s low-voltage wiring, which we recommend leaving to a licensed technician.
Want Help Programming It?
We’re happy to set up your schedule, configure humidity control, and connect it to the Skyport app while we’re already there.
See our smart thermostat installation service or the How-To Hub.
This guide is general homeowner information and is not a substitute for the manufacturer’s own manual or support resources. ProStat+ and Prostat+ are trademarks of their respective owner.
