APOLLO Wi-Fi Boiler Thermostat

A boiler thermostat controls room air temperature: it senses how warm the living space is and calls the boiler for heat when the room drops below the setpoint. An aquastat, by contrast, controls the boiler's water temperature at the boiler itself. Most hydronic systems use both together. The APOLLO Wi-Fi Boiler Thermostat is the room-control side — a wall-mounted thermostat and boiler remote control panel with a 3.5-inch color touchscreen and Wi-Fi app access. If you need water-temperature control instead, see the APOLLO Wi-Fi Boiler Aquastat in the model dropdown at the top of this page.

Most boilers accept a simple two-wire, dry-contact call for heat on their thermostat terminals (often labeled T-T). The APOLLO's SPST relay output (5A maximum, with COM/NO terminals) connects to those terminals: when the room calls for heat, the relay closes the circuit and the boiler fires. Supply power for the thermostat itself can come from 12–24VAC/DC or 110–240VAC, so it works with both low-voltage control wiring and line-voltage locations. The full wiring diagram is in the product manual, downloadable in the documents section of this page. If you're unsure about your boiler's terminals, have a heating technician make the final connection.

Yes. The APOLLO connects to a 2.4GHz network using IEEE 802.11 b/g/n with WPA/WPA2 security. From the companion app you can adjust the room setpoint, switch work modes, view current temperature and humidity, and manage 7-day schedules from anywhere. GEO-fence automation sets the temperature back automatically when you leave and restores comfort before you return. Modbus RTU and Modbus TCP are supported for building management integration, along with Google Home monitoring.

Any hydronic boiler that accepts an external thermostat call on dry-contact terminals: gas, oil, electric, wood, and pellet boilers. For solid-fuel boilers the APOLLO goes further than a basic on/off thermostat — its remote-control-panel function supports work modes, fuel level display, and alarm notifications, so you can keep an eye on a wood or pellet boiler from the living space instead of the boiler room. MBTEK's wood gasification and pellet boiler lines pair directly with it.

Beyond calling for heat like a standard room thermostat, the APOLLO acts as a remote control panel for the boiler: it can display and switch boiler work modes, show fuel level for compatible solid-fuel boilers, and surface alarm notifications at the thermostat and in the app. That means fewer trips to the boiler room — status, warnings, and mode changes are handled from the wall unit or your phone.

Yes. The APOLLO includes a 17 ft external sensor that can be placed for remote room sensing, outdoor temperature reading, or boiler monitoring, and a 33 ft sensor is available as an accessory for longer runs. With an outdoor sensor placement the thermostat supports weather compensation — adjusting heating behavior based on outdoor conditions so the system responds before the indoor temperature sags on cold days.

A programmable boiler thermostat stores a fixed weekly schedule and runs standalone — reliable, but changing the schedule means standing at the wall unit. A smart Wi-Fi boiler thermostat like the APOLLO adds remote app control, GEO-fence automation based on your phone's location, boiler status and alarm visibility from anywhere, and Modbus connectivity for larger systems. For hydronic heat, which responds slowly, the ability to adjust remotely before you arrive home is a real comfort and efficiency gain.

The boiler thermostat is part of the APOLLO Wi-Fi thermostat platform, which also includes dedicated models for boiler aquastat (water temperature) control, fan coil units, radiant floor heating, pool and spa aquastat, snow melt systems, and electric baseboard heaters. Each model is pre-configured for its application — select the one that matches your system from the dropdown at the top of this page.