What Are They?
A heat pump is a mechanical-compression cycle refrigeration system that can be reversed to either heat or cool a controlled space.
What does that mean?! Think of a heat pump as a heat transporter constantly moving warm air to wherever it’s needed. Heat pumps are really just conventional HVAC air conditioning systems that have the ability to
either run forward (and supply cool air) or run backwards (and supply warm air).
What Do They Do?
When it’s cold outside, a heat pump extracts what outside heat is available and transfers it inside.
When it’s warm outside, it reverses directions and acts like an air conditioner, removing heat from your home.
What Are They Made Of?
The key part of a heat pump system is the reversing valve. The reversing valve determines the direction of the flow through the HVAC compressor.
There are two types of reversing valves: Type O and Type B.
The difference between these Type O and Type B valves is their default state--the state they are in when they are not receiving a signal from the thermostat:
Type O default state = heating.
Type B default state = cooling.
The Quext thermostat has a single terminal (Aux) that connects to the reversing valve. The user then programs the Quext thermostat to tell it which type of reversing valve is being used.
Heat Strips
Electric heat strips are another part of the heat pump. Heat pumps become very inefficient when outside temperature drop below 40 degrees F. The heat strips are then turned on as either Aux Heat to help the heat pump, or as E Heat to replace the heat pump (only available in Heat Mode / not Auto).
Aux Heat - The thermostat is set to Heat, has been heating for 15 minutes, but has not reached the set point. So, Aux heat turns on the electric heat strips to help reach the set point.
E Heat - Turned on by setting the thermostat to Heat, then pressing and holding the knob for 3 seconds. E Heat can also be turned on from within Quext.io and the mobile app. This sets the thermostat to use only the electric heat strips for heating.
NOTE: Once enabled, E Heat remains enabled each time the thermostat calls for Heat.
Quext Thermostat Heat Pump Wiring Diagram
Reversing Valve O
Default valve position = Heat
Thermostat setting = 12
Reversing Valve B
Default valve position = Cool
Thermostat setting = 11
Ready to Program your Thermostat?
Follow this guide to take those next steps.
Need help?
Use the Chat with Support feature in your Quext portal or Quext app .
You can also search our full help desk library within your Quext Help Center.