APOLLO Wi-Fi Radiant Floor Thermostat

A radiant floor thermostat controls hydronic in-floor heating rather than a furnace or air handler. Instead of a simple on/off call, it switches a motorized zone valve, circulator pump, or boiler call for 1-stage heat / 1-stage cool, timed around the slab's thermal lag. Because concrete or tile stores heat, the thermostat reads floor temperature directly through an external sensor rather than relying on room air alone — the APOLLO Wi-Fi Radiant Floor Thermostat ships with a 20 ft external sensor, accepts 12–24VAC/DC or 110–240VAC power, and adds Wi-Fi app control on top.

Hydronic radiant heat circulates hot water through PEX tubing in the slab; the thermostat switches a motorized valve, circulator pump, or boiler call. Electric radiant heat uses resistive heating cable or mats embedded in the floor; the thermostat switches that electric load directly through its relay and must carry built-in GFCI protection. The APOLLO Wi-Fi Radiant Floor Thermostat is a hydronic-only controller — it drives a 1-stage heat / 1-stage cool motorized valve and does not have GFCI protection. If you have electric heating cables or mats, you need a thermostat rated to switch the electric heating load directly through its relay — a different product from this one.

Yes. Slab and tile have enough thermal mass that air-only sensing overshoots or undershoots the actual floor temperature, wasting energy and risking overheated flooring. The APOLLO thermostat includes an external 20 ft sensor that can be placed in the floor, at a remote room location, or outdoors, so the setpoint tracks the surface you're actually heating rather than just the surrounding air.

No. Nest, Ecobee, and similar mainstream smart thermostats are built for single-stage forced-air furnaces and air conditioners — they have no floor-sensor input terminal and no logic for the slow thermal response of a heated slab, and they aren't wired to properly drive a hydronic zone valve or circulator relay. A dedicated hydronic radiant thermostat like the APOLLO, with a floor sensor input and valve-switching relay logic, is required for correct operation.

Yes. The APOLLO thermostat connects to a 2.4GHz network using IEEE 802.11 b/g/n with WPA/WPA2 security. The companion app lets you adjust the setpoint, view floor and room temperature, manage 7-day schedules, and set up GEO-fence automation from your phone. Wired BACnet MSTP, BACnet/IP, and MQTT are also supported for building management system integration, along with Google Home for voice-based monitoring.

It depends on your comfort with electrical work. Installation involves wiring the thermostat to its 12–24VAC/DC or 110–240VAC power supply, connecting the relay to your zone valve, circulator, or boiler call, and routing the external floor sensor into the slab or subfloor. This is a reasonable DIY project for anyone comfortable with low-voltage control wiring who follows the wiring diagram in the product manual — but a licensed electrician or hydronic technician is recommended for line-voltage hookups, multi-zone systems, or where local code requires a permit.

Prioritize a floor sensor input rather than air-only sensing, a power supply that matches your wiring (12–24VAC/DC or 110–240VAC), a relay rated for your zone valve or circulator load (the APOLLO is rated 5A maximum, SPST-NO), Wi-Fi app control, and scheduling that accounts for the slab's slow response — geofence and adaptive recovery matter more here than on forced-air systems. For commercial or multi-zone jobs, wired BACnet MSTP, BACnet/IP, or MQTT support for building management system integration is also worth checking.

A concrete or tile slab has enough thermal mass that it heats and cools far more slowly than air, so the aggressive on/off cycling used by forced-air thermostats will overshoot the setpoint or waste energy short-cycling the zone valve. Radiant floor schedules work better with an earlier pre-heat ramp before occupancy rather than a sharp setpoint jump. The APOLLO thermostat's 7-day scheduling, GEO-fence setback, and auto-detect mode (using built-in ambient light and humidity sensors) are tuned to work with that lag rather than against it.

The APOLLO Wi-Fi Radiant Floor Thermostat works with hydronic loops supplied by an air-to-water heat pump, or by an oil, gas, or electric boiler. It's part of the same APOLLO thermostat platform as the fan coil thermostat, boiler thermostat, boiler aquastat, pool/spa aquastat, snow melt controller, and electric baseboard thermostat — if you're building a multi-zone system with both fan coils and radiant floor loops, select the matching model from the dropdown at the top of this page for each zone type.