Weather compensation

  • Overview
  • Tools and apps
  • FAQ
  • Case stories
  • Videos

The weather is the main influence on the heat demand of a building. In cold periods the building requires more heating, and vice versa when the breezes in the surrounding area are warmer.

The weather constantly changes, and so does the heat load required to warm up a house. Compensating for the weather influence is therefore a rational and sound way to achieve energy savings. Our electronic controllers with weather compensation help you achieve such energy savings through intelligent heating control.

Weather Compensation in District Heating Systems

The optimum heat supply to a building is when the demand is met and nothing is in excess. An intelligent electronic controller for weather compensation in the heating system can proactively adjust the supply of heat to keep it at exactly that point by detecting changes in the weather conditions outside. In contrast, a heating system without a weather compensator will only react to the current indoor temperature, and thus be prone to delayed reactions when changes occur outside. This negatively affects both user comfort and energy efficiency.

How does it work?

The weather compensator gets its signal from an outdoor temperature sensor placed on the shadow side of the building. The sensor registers the actual temperature and the electronic controller adjusts, if necessary, the heat supply (flow temperature) to reflect the new conditions. The controller will also adjust the heat supply to the radiators and ensure that room temperatures are kept constant. The user will thereby not even notice that the weather has changed outside and experience the same temperature and comfort at all times.

10 - 40% energy savings with electronic weather compensation

A report by COWI, a leading environmental science consulting group, puts the estimated energy savings with electronic weather compensators in one-family houses at 10% and in some cases as much as 40%. According to the report, one-family houses with large heat consumption gain particularly fast returns on investment after installing electronic weather compensators.

Besides this, legislative regulations for multi-family and commercial buildings prescribe weather compensation. In more and more countries, this also applies to one-family houses.

A heating system with electronic weather compensation can have additional control functions, such as:

  • Flow and capacity limitation
  • Temperature limitation possible for primary return temperature and/or secondary flow temperature
  • Safety function can be established
  • Periodic system set-back function
  • Possibility of data communication to e.g. a SCADA system or via a web portal
  • Logging of energy consumption data

Systems with weather compensation are mainly used in radiator and floor heating systems. 

Features and benefits

Easy access to navigate in the intuitive menu structure with wheel or the turn-push dial of the ECL controller

Improved cable connections and more space for wiring ensure a fast and trouble-free installation of the ECL Comfort controller in the system

11 – 15 % savings on energy consumption in the building and reduced CO2 emissions

Tools and apps

Software tools


2-point control, also called ON-OFF control, is used by an electronic controller or an electric thermostat to switch ON or OFF for example a gas boiler, an oil burner, a heat pump, a circulation pump, a fan and so on.

The outdoor temperature sensor is connected to the master. Most common failure is a forgotten setting in the slave's address menu. It must not be address 15. It can be 0, 1, 2 . . . 9. Besides the outdoor temperature value, the slave receives Time & Date information from the master.

Simply, the resistance of the cable between the temperature sensor and the ECL controller has a minor influence on the measured temperature.
Max. length of copper cable type, in different dimensions, for one degree higher read-out of the temperature is:
44 m @ 0.4 mm²
55 m @ 0.5 mm²
83 m @ 0.75 mm²
110 m @ 1.0 mm²
165 m @ 1.5 mm²
275 m @ 2.5 mm²

Pt" means Platinum which is a metal.
"1000" means 1000 ohm at 0 (zero) °C.
The unit "ohm" expresses the electric resistance. Platinum has a positive temperature characteristic (PTC). This means that the initial resistance of the metal increases when its temperature rises.The resistance increases with 3.85 ohm per degree (on the Celsius scale). The characteristic is very linear in the temperature range from -60 to 200°C. Example: Measuring a resistance of 1077 ohm means a temperature of 20°C.

A temperature difference in degrees on the Celsius scale.
Example: At 10 o'clock the outdoor temperature was 14 °C, at 13 o'clock the outdoor temperature was 19 °C. The outdoor temperature has increased with 5 K.

From cold water supply side there is a constant flow. The 3-port valve makes a partly flow through the heat-exchanger and a partly flow through the B-port of the valve.
These two flows are different, depending on the demand for cooling.

Yes, we have an option by combining the remote unit, ECA 31, in an application with ECL 210 or ECL 310. In the ECA favorite display the ECA 31 will show the relative humidity.

The ECA 32 is placed in the base part of the ECL 310. Communication with the ECL 310: A 2 x 5 male-pin arrangement on the back of the ECL 310 controller connects to the related 2 x 5 female-pin arrangement on the ECA 32, when the ECL 310 is placed in its base part.

Temperature sensors, pulse inputs and analog outputs are connected via the terminals 49 - 62. 4 x relay outputs are via the terminals 39 - 46.

ECA 32 is used only together with ECL 310 and applications having ECA 32 related functions.

Besides, ECA 32 can be used as monitoring module:
6 x temperature sensor inputs (Pt 1000)ECL 310. In the ECA favorite display the ECA 31 will show the relative humidity.

A Master - Slave system is ECL Controllers in internal connection by means of the ECL 485 bus.

The Master (address 15) sends T.out, Time and Date to the Slaves. The Master can receive the T.flow.ref from addressed Slaves.
Slaves with address 0, 1 - 9 are listeners (receive info about T.out, Time and Date, send by the Master).
Slaves with address 1 - 9 (one address for each slave) can send the T.flow.ref to the Master.

Max. 2. This limitation is because of the power demand from each ECA 30.

A Master - Slave system with ECL Comfort 110 controllers in internal connection by means of the ECL bus.

The master has the outdoor temperature sensor connected. Via the ECL bus the T.out signal is sent to the slaves and the ECA 60 / 61.

Multiple ECL 110 in a multi-family house can have one T.out sensor in common.

ECL 110 cannot be connected to the ECL 485 bus network with ECL 210 or ECL 310.

In the heating circuit control in the ECL 210 / 310, the parameters 1x182 and 1x183 are set to 0.0.
T. room is still displayed.

After 20 minutes or a power reconnection all settings are locked. All settings can still be seen.

A listener is a slave controller with address 0 in a master - slave system. A listener receives T. out, time and date from the master. A listener cannot be used with a ECA 30/31.

ECA 30/31 cannot communicate with address 0!

In total 20.
When the listener only needs to receive the T.out signal, the address must be set to "0".

When the listener needs to receive the T.out signal and send back to the master the T.flow.ref, the address must be set to either 1, 2 . . . or 9.

The ECL 110 has a bus called ECL bus.
The ECL 210 and ECL 310 have another bus called ECL 485 bus. These buses are totally different.

When uploading an application in the ECL 210 / 310 controller, the communication between ECA 30 and the ECL is slow.
When the application has been uploaded in the ECL controller, the ECA 30 will be updated and having a much quicker reaction.

Procedure for setting up ECL Comfort controllers (B - types) with one ECA 30.

3 controllers, ECL 210 B (without display and dial)
One master: Application A266
Two slaves: Application A260, addresses numbers 1 and 2.
One ECA 30.


  • The master must send T.out to slaves
  • ECA 30 must be used for setting all 3 x ECL 210 B controllers
  • ECA 30 must be used for monitoring

It is assumed that all connections for sensors, ECL 485 bus, actuators and pumps are done.
The outdoor temperature sensor must be connected to the base part of the master controller.


1. Don't place any ECL controllers in any base part.
2. Connect the ECA 30 to the ECL485 bus (cable type: 2 x twisted pair)

Be sure that the ECL485 bus connections share the common terminal (30) and +12 V (31) for all the base parts with the ECL485's A and B connections.

3. Insert in its base part the ECL controller which must be addressed with the lowest slave number, for example "1".

4. Power up the units. The ECL and ECA 30 are assumed to be new from factory.

4.a. If the controller is not new from factory, do following:
In ECA 30:
> ECA MENU, > ECA factory > Reset ECL addr. > Reset ECL addr. > "Yes".
After 10 sec the ECA returns to "ECA factory" menu. The ECL address has now been set to 15. (See extra info "Reset ECL address" at the end of this document).

4.b.If the ECA 30 is not new from factory, do following:
> ECA MENU, > ECA factory > ECA default, > Restore factory, > (Choose factory), > "Yes".
This will ensure that the ECA has address A and it is connected to address 15 which is required in order to install an application in the ECL controller.

5. Insert the appl.-key A260 in the ECL controller (the slave)

6. Choose language

(the reaction time during steps 5 - 11 seems slow. This is because the ECL controller and the ECA 30 are not fully synchronized)

7. Choose application (not possible for A260 because only one subtype exists).

8. Set Time and date

9. Choose "Next"

10. Display shows shortly "Application A260.1 installed"
- the application is uploaded.
- the display in the ECA 30 is not illuminated for 10 sec.

11. The display shows an application related menu.

12. After 10 - 30 seconds a menu "Copy application" appears (the ECA 30 must know the ECL application)

- Choose "Yes"
(the "Copy" procedure takes some minutes)

13. (Giving the slave an address number)
a. Select an ECL menu
b. Choose MENU
c. Choose "Common controller settings"
d. Choose "System"
e. Choose "Communication"
f. Choose "ECL 485 addr."
g. Select "ECL 485 addr."
- ID = 2048, factory set value is "15"
h. Change the address to the planned address number for this slave
i. After 5 sec, the chosen address number changes to a "0"
j. After further 5 sec, the display returns to "ECA MENU"
- in addition, a controller icon with a cross is present.
This means that there is no communication between the ECL controller and the ECA 30. A master is not present on the ECL 485 bus.

14. (Next ECL set-up)
Insert in its base part the ECL controller which must be addressed with the next slave number, Ex. "2"

15. (Setting the ECA to communicate on address 15)
a. Choose the ECA MENU
b. Choose "ECA system"
c. Choose "ECA communication"
d. Choose "Connection addr."
e. Change to "15"
The "key insertion animation" from the ECL controller will now be shown on the ECA 30.

16. (application upload)
Follow points 6 – 13
If slave 1 and 2 have the same application (same version and language), it is not necessary to copy the application again (point 11).

17. (Next ECL set-up)
Insert in its base part the ECL controller which must be the master (address number 15).

18. Follow points 15.a - 15.e

19. Follow points 6 - 12.

20. The Master controller has address 15 from the factory, so it does not need to be addressed.

21. The entire communication set-up is finished.

22. (to communicate with the master or the slaves)
a. Choose the ECA MENU
b. Choose "ECA system"
c. Choose "ECA communication"
d. Choose "Connection addr. to "15" (= Master), "1" (= Slave no. 1), "2" (= Slave no. 2)

Communication with the slaves is only possible when a master (addr. 15) is present in the system.
Newer versions of ECA 30 / 31 have the facility that you can select slave number directly from the display.

Reset ECL address:
The "Reset ECL address" is a special emergency function that can reset the ECL 485 address of all controllers connected to the ECL 485 network to "15" (Master address). This function has been made because it is possible to change the master’s address to something else which will leave the network without a master and the ECL485 bus will therefore no longer function. This is critical if the master controller is a blind controller which needs communication with an ECA 30/31 in order to be operated.
To ensure that the function is not used unless necessary, it is made so that the “Reset ECL address” menu can only be activated if:

* Dead Connection mode is activated (only one bar in the navigation bar in the lower right corner of the ECA 30 / 31's display)

* A master synchronization broadcast signal has not been received for at least 25 seconds

When the reset menu has been activated, the ECA 30 / 31 will send pseudo master broadcasts for 10 seconds in order to bring the ECL controllers out of an initialization phase. The ECA 30 / 31 will then start to send address change commands to ECL 485 addresses 1-14 (Because in some early ECL version it was possible to set the address to 10-14). This will take approximately 15 seconds. As all ECL controllers on the ECL 485 network will get their ECL 485 address changed to 15 it is recommended that all other controllers except for the intended master controller are turned off (or removed from its base part) before this function is activated. The whole operation will take approximately 25 seconds. If multiple controllers end up with address 15 then there is a risk that they will conflict with each other. It is therefore necessary to manually check and reset the ECL 485 addresses of slave controllers after this function has been used.

The ECA 30 / 31 is developed for being used with the ECL 210 / 310 series.

A368 appl.-key was originally made with A368.1, A368.2, A368.3 and A368.4.

As per January 2014 the A368 appl.-key contains two extra subtypes, A368.5 and A368.6.

Main items in A368.5:
F1 is a flow meter to measure the refill water volume. The pulses from the flow meter are applied to the ECA 32 module's pulse input.

S11 is temp. monitoring of heating, secondary return.

S13 is temp. monitoring of DHW circulation, return.

Main items in A368.6:

S2 is temp. monitoring of heating, secondary return.

S8 is temp. monitoring of DHW circulation, return.

One DHW circulation pump (P1).

Mounting Guide has been updated.

Installation Guide in English has been updated.

A247 was originally made with A247.1, A247.2, A347.1 and A347.2.
As per January 2014 the A247 appl.-key contains an extra subtype, A247.3.

Main differences, compared to A247.1:
No alarm
S7 is DHW-charging temp. Sensor
S4 is DHW-heating temp. Sensor
P2 is DHW primary circuit circulation pump
P4 is DHW-charging pump.

Mounting Guide has been updated.
Installation Guide has not been updated yet.

Unfortunately, we have seen some ECL 210 base parts where the right terminal block's position has changed in up-down direction. This means that temperature sensors are not seen correctly from the ECL 210.
Correct position is with two terminals space above and below the terminal block.
As from start of year 2012, the production line has tested correct terminal block position.

As the ECA 60 is discontinued and the ECA 61 is for service only we for now (August 2014) don’t have an offer despite of the room sensor ESM-10.

Case stories