Shop by Product Line
Underfloor Heating Mats
Tekmar Controls
Mixing Controls
Mixing Valves
Setpoint and Pump Controls
Snow Melting Controls
tekmarNet Controls
Heating System Controls
Tubing Fittings
Watts Onix Tubing
Watts Radiant RadiantPERT Coil
Coil Watts Radiant BarrierPEX+
Nibco Barrier PEX
Nibco Dura Pex
Tubing Clips & Ties
  Tekmar Boiler Control-Three Modulating Boiler & DHW/ Setpoint
Tekmar Boiler Control-Three Modulating Boiler & DHW/ Setpoint
Click to enlarge

Tekmar Boiler Control-Three Modulating Boiler & DHW/ Setpoint

The Boiler Control 265 is designed to stage multiple modulating boilers using Outdoor Temperature Reset. It can be used in applications ranging from baseboard or radiant heating systems, to dedicated domestic hot water heating in commercial buildings. This control regulates a single heating water temperature through Outdoor Temperature Reset and/or setpoint/DHW control. It is capable of controlling (stage and rotate) up to 3 modulating boilers by using a native 4-20 mA (or 0-20 mA) signal that can be converted to 2-10 V (dc) or 0-10 V (dc), as well as the system pump.


  • Advanced settings to fine-tune building requirements
  • Automatic Boiler Differential
  • Boiler pump operation
  • Control up to 3 modulating boilers
  • DHW Priority (optional)
  • DHW pump or valve operation
  • Equal Runtime Rotation
  • Exercising
  • Outdoor Temperature Reset
  • Powered boiler pump output
  • Quick setup for easy installation and programming of control
  • Setback input for energy savings
  • Test sequence to ensure proper component operation
  • User comfort adjustment to increase or decrease building space temperature
  • Warm Weather Shut Down


Control Microprocessor control. This is not a safety (limit) control
Packaged weight 3.3 lb. (1550 g)
Dimensions 6-5/8" H x 7-9/16" W x 2-13/16" D (170 x 193 x 72 mm)
Enclosure Blue PVC plastic, NEMA type 1
Approvals CSA C US, meets class B: ICES & FCC Part 15
Ambient conditions Indoor use only, 32 to 122°F (0 to 50°C), RH ≤80% to 88°F (31°C), down to 50% above 104°F (40°C), Altitude <6560 ft. (2000 m), Installation Category II, Pollution Degree
Power supply 115 V (ac) ±10%, 50/60 Hz, 600 VA
Relay capacity 230 V (ac) 5 A, 1/3 hp, pilot duty 240 VA
Demands 20 to 260 V (ac) 2 VA
Sensors NTC thermistor, 10 kΩ @ 77°F (25°C ±0.2°C) ß=3892
-Included Outdoor Sensor 070, 2 of Universal Sensor 071, and 4 of 500&#8486; Resistor
-Optional tekmar type #: 071,082
Warranty Limited 3 Year Warranty

Current Literature

Product Submittal

Jan 2012 - Present


Installation & Operation Manual

Jul 2010 - Present


Application Brochure

Jul 2010 - Current


Installing the 263 and 265 Modulating Boiler Controls with Modulating Boilers

Mar 2011 - Present


RF Noise Interference

May 2009 - Present


Energy Savings with Outdoor Reset Brochure


Part Number: 265

2 +$1,260.88

Tell a Friend