Tekmar Thermostats

Tekmar thermostats are hydronic and radiant heating controls engineered specifically for the precision demands of wet systems, including radiant floor, baseboard, fan coil, and multi-stage forced air applications. The tekmar thermostat line spans from simple one-stage models like the 518, which uses Pulse Width Modulation (PWM) technology to keep room temperature within tight tolerances, to fully communicating touchscreen units capable of managing two heating stages, one cooling stage, a fan, and relative humidity simultaneously. Where a standard HVAC thermostat treats heat as on or off, tekmar thermostats modulate output to minimize swings, which matters a lot when there's a slab sensor involved and a heated floor is part of the picture. SupplyHouse carries the full range, from basic single-stage wall stats to WiFi-enabled and tekmarNet communicating models, so contractors can spec the right control for the system in front of them rather than settling for something close enough.

KEY SUBCATEGORIES / PRODUCT TYPES

One-Stage Radiant Thermostats

The tekmar 518 is a microprocessor-based one-stage thermostat built for hydronic heating zones. It uses PWM technology to modulate the call for heat, reducing temperature swings compared to simple on/off switching. An auxiliary sensor input accepts a floor sensor for floor temperature limiting, making the 518 a practical choice for radiant slab installations where floor protection matters. Dimensions are 3-11/16" H x 3" W x 15/16" D, and the unit operates on 10 to 30 V ac/dc at 50/60 Hz. The 518 replaced the discontinued 507 and 508 models and installs as a direct drop-in for either.

One-Stage Radiant Thermostats with Slab Sensor

The tekmar 519 packages the 518 thermostat with a Slab Sensor 079 included, so the floor temperature loop is ready to commission out of the box. PWM control keeps the zone call for heat smooth, and the slab sensor input lets installers set both floor minimum and maximum limits, which protects hardwood and engineered flooring from overheating. The 519 replaces the discontinued tekmar 509. Floor temperature range spans 40 to 122°F, though consult tekmar installation documentation for recommended maximums based on floor type.

WiFi Thermostats

The tekmar 561 WiFi Thermostat delivers remote temperature control for one-stage heating systems via the Watts Home mobile app on iOS and Android. A 3.5-inch color touchscreen handles local control, and the 7-day, 4-event programmable schedule includes an Early Start function that learns how long the system takes to reach setpoint and fires up accordingly. An Away mode overrides the schedule to reduce heating when the space is unoccupied. The 561 supports an optional floor sensor for radiant applications and provides energy monitoring, automatic software updates, and outdoor temperature display. The Invita WiFi Thermostat 564 extends WiFi capability to conventional, heat pump, and dual-fuel systems using just 2 existing wires from the living space, connecting to an HVAC Interface Module in the mechanical room. The 564 operates heat pump systems down to minus 22°F before engaging a secondary heat source, covers built-in fan, relative humidity, and ventilation control, and carries the ENERGY STAR mark.

tekmarNet Communicating Thermostats

tekmarNet thermostats communicate with tekmar zone controls, wiring centers, and house controls over a dedicated 2-wire or 4-wire bus, allowing setpoint, schedule, and event data to propagate from a primary thermostat to connected zone stats. The tekmar 532 is a one-stage communicating thermostat with two auxiliary sensor inputs assignable to room, floor, or outdoor temperature, and it installs as either a networked tekmarNet device or a standalone stat on 3 wires. The tekmar 553 is a touchscreen communicating thermostat handling two heating stages, one cooling stage, a fan, and relative humidity. Heating stages on the 553 can be hydronic, forced air, or a single-stage heat pump, and the cooling stage supports either an air conditioner or heat pump. The 553 connects to tekmarNet controls on 2 or 4 wires or operates as a standalone device using separate power.

Programmable Multi-Stage Thermostats

The tekmar 521 Programmable Thermostat covers three operating modes: single-stage heating, two stages of heating with a fan, or one stage of heating and one stage of cooling with a fan. A Slab Sensor 079 is included, and two additional auxiliary sensor inputs can be wired for floor, outdoor, or room monitoring. The programmable schedule runs either a 7-day or 24-hour pattern with 2 or 4 events per day. PWM operation cycles heat on and off within plus or minus 1.5°F of the temperature setting, which is tight enough for comfort and floor protection in most radiant installations. An optional Adaptor Plate 012 allows mounting on a single-gang electrical box.

BUYING GUIDE / HOW TO CHOOSE

Choosing the right tekmar thermostat starts with the system type, not the features list. For a single-zone hydronic or radiant installation with no cooling and no network controls, the 518 covers the job. If a slab sensor is part of the spec, consider the 519 instead and skip the separate sensor order. The PWM operation on both models is the actual reason to choose tekmar over a generic residential stat for radiant work: PWM modulates the heat call rather than banging the zone valve open and closed, which translates to fewer temperature swings in the slab and better occupant comfort.

For installations requiring remote access, the tekmar 561 WiFi Thermostat handles one-stage heating systems with app control via the Watts Home platform. Vacation homes, rental properties, and any application where a homeowner wants to check setpoints from a phone are natural fits. When the existing thermostat wire is just 2 conductors and the system includes a heat pump or forced air furnace, the Invita WiFi Thermostat 564 does the job without pulling new wire.

Multi-stage and networked applications call for tekmarNet communicating thermostats. The tekmar 532 works for single-stage zones in a networked system. For a system with two heating stages, one cooling stage, and humidity control, the tekmar 553 is the spec to reach for. Contractors working with tekmar House Controls, Zone Managers, or Wiring Centers should confirm which tekmarNet generation the existing controls support before ordering a communicating stat. The 553 works in standalone mode when a tekmarNet system isn't present, which is worth knowing on retrofit jobs where the zone controls haven't been touched.

Ambient operating range for tekmar thermostats is 32 to 122°F (0 to 50°C), non-condensing, for indoor use only. Verify power supply voltage requirements against the specific model before ordering.

FAQs

What's the difference between the tekmar 518 and tekmar 519?

The difference between the tekmar 518 and tekmar 519 is the inclusion of a Slab Sensor 079 packaged with the 519. Both thermostats use PWM technology for one-stage hydronic heating and share the same 3-11/16" H x 3" W x 15/16" D enclosure. The 519 is a direct replacement for the discontinued tekmar 509, while the 518 replaced the 507 and 508 models. Either thermostat accepts an optional floor sensor for installations that require floor temperature limiting.

How does the tekmar 561 WiFi Thermostat work with radiant floor heating?

The tekmar 561 WiFi Thermostat controls one-stage heating systems and supports an optional floor sensor for radiant applications. The floor sensor, purchased separately, connects to the thermostat's auxiliary sensor input and allows floor temperature limiting alongside air temperature control. The 561 includes a 3.5-inch color touchscreen, a 7-day programmable schedule with 4 events per day, and an Early Start function that automatically learns how long the system takes to reach setpoint. Remote control is handled through the Watts Home mobile app on iOS and Android.

What is the difference between a tekmarNet thermostat and a standard tekmar thermostat?

The difference between a tekmarNet thermostat and a standard tekmar thermostat is communication capability. Standard tekmar thermostats like the 518 and 519 operate as standalone controls, independently managing a single zone. tekmarNet thermostats like the 532 and 553 communicate over a 2-wire or 4-wire bus with tekmar zone controls, wiring centers, and house controls, allowing schedule, setpoint, and event data to be coordinated across multiple zones from a single control point. tekmarNet thermostats can also operate in standalone mode when no network control is present.

Can the tekmar 553 control both radiant floor heating and forced air in the same zone?

The tekmar 553 tekmarNet Thermostat can manage two heating stages, and those stages can be any combination of hydronic, forced air, or a single-stage heat pump. An optional floor sensor connects to one of the 553's two auxiliary sensor inputs to control floor temperature while maintaining the desired room air temperature. The 553 also handles one cooling stage, a fan, and relative humidity through its built-in humidity sensor, making it a viable spec for mixed-system applications where a radiant floor and a backup forced air source share a zone. Consult tekmar engineering documentation for specific wiring configurations.

What systems is the Invita WiFi Thermostat 564 compatible with?

The Invita WiFi Thermostat 564 is compatible with most types of residential heating and cooling systems, including conventional, heat pump, and dual-fuel configurations. The 564 uses just 2 existing wires from the living space to connect to an included HVAC Interface Module installed in the mechanical room, eliminating the need to pull new thermostat wire. Built-in controls cover fan, relative humidity, and ventilation. For heat pump applications, the 564 includes an adjustable balance point that operates the heat pump down to minus 22°F before engaging a secondary heat source.