The AHD20 is a compact, weather compensated controller built into the actuator housing. It is used to control the mixing valve and the circulation pump to regulate the supply temperature during heating or cooling, depending on the outdoor temperature.


Application AHD20

  • Weather-compensated heating and/or cooling control.
  • Control of independent mixing circuit (mixing valve and circulation pump).
  • Control of additional mixing circuit (mixing valve and circulation pump).


Advantage AHD20

  • 2 pre-set hydraulic schemes.
  • Possibility of connecting up to 4 sensors (supply, outdoor, room/return, power source).
  • Two operating modes, weather compensated (by outdoor temperature) or thermostatic (by room temperature).
  • Intuitive setting with use of keypad and color display.
  • Possibility of connecting a return sensor and limiting the power of the heating circuit.
  • Quick and easy “click” type installation system on mixing valve.
  • Automatic screen adjustment according to the instalation direction.
  • Possibility of operating without a room unit (according to the heating curve).
  • Possibility of BUS connection with several controllers when using a larger system.
  • Error diagnostics and automatic activation of an alternative operating mode.
  • Connectivity to the SeltronHome platform with remote control option.

Weather compensated heating and/or cooling control 
Mixing heating circuit control (mixing valve and circulation pump) 
Technical features
Number of pre-set hydraulic schemes2
Number of electronic relays1
Number of temperature sensors inputs4
Temperature setup option 10 to 90 °C 
Additional sensor for measuring the source temperature 
BUS option - interconnection of AHD controller or with other Seltron heating controllers 
User functions
Room heating or cooling according to the timer programme 
Heating system protection
Frost protection 
Antiblock function for mixing valve 
Antiblock function for pump 
Limiting the maximum supply temperature for floor heating 
Data display
Display of notifications and warnings about the heating system operation 
Display of temperatures and other operating data 
Detailed display of temperatures for the current day 
Review of temperature data for the previous week 
Signalling of the mixing valve rotating direction 
Control and signalling of the circulation pump operation 
Remote access
Possibility of USB connection to a personal computer 
Possibility of connectivity to the SeltronHome platform, which allows remote control via a smartphone or tablet 
Setting and installation
Wizard for an easy and quick device start-up 
14-language user interface. Languages EN, DE, FR, NL, PL, ES, SL, IT, CZ, SK, HR, RU, HU and UA 
Connection box for sensors 
Setting of the operation by selecting the hydraulic scheme 
Setting of the rotation direction of the mixing valve 
Logging and display of changes made to the setup 
Allows recalling basic settings in case of loss or unwanted changes 
Suitable for installation on different types of mixing valves 
"Click" type installation system 
Connection box for sensors is prewired to the controller 
Power cord equipped with plug 

TFT displayYes
Own consumptionMaximum 3.5 W
Standby power consumptionMaximum 0.25 W
Torque6 Nm
Rotation angle90 < °
Rotation speed2 min 90 < °
Mixing valve control3-point PID
Circulation pump control2-point (ON/OFF)
Relay outputelectronic relay, 1 (1) A ~, 250 V~
Supply voltage230 V ~, 50 Hz
Maximum own consumption5 W
Power supply of built-in clockBattery CR1025 (Li-Mn) 3 V
Accuracy of built-in clock+/-1 s (24 h) at 20 °C
Degree of protectionIP42 according to EN 60529
Safety classI according to EN 60730-1
Type of temperature sensorsPt1000
Housing materialPC - dark grey
Operating temperature0÷50 °C
Storage temperature-20÷65 °C
Product weight1.000 g
Number of pieces in a package unit12 pieces
Electrical connectionElektro priključitev AHD20

  Article - Nr. Products
1AHD2021-050 1AHD2021-050 Compact weather compensated controller SELTRON AHD20, 2x TF/Pt, 1xAFD/Pt
1AHD20W21-050 1AHD20W21-050 Compact weather compensated controller SELTRON AHD20W, wireless, 2x TF/Pt, 1xAFD/Pt
1FODPT-NN0 1FODPT-NN0 Outdoor temperature sensor SELTRON AFD/Pt
1RCD2W-050 1RCD2W-050 Digital room unit SELTRON RCD2, white
1GWD2-040 1GWD2-040 Communication module SELTRON GWD2