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Heating Function: How does hourly programming work?

For each day of the week, the customer can schedule the time that the system needs to heat the water a pre-determined setpoint. The customer can pre-set 2 different setpoints: Eco and Comfort. 

  • For example, the Eco setpoint can be 50°C and the Comfort setpoint can be 60°C. These setpoints can be changed by the customer.

The schedule set for one day can easily be copied to other days.

How can customers set the Eco and Comfort setpoints?



How does the reheating function work?

In Reheat Mode, when the temperature in the domestic hot water tank drops below a certain value, it heats up continuously until it reaches the temperature indicated by the customer (e.g., a Reheat setpoint of 50°C). The temperature in the tank that triggers the heating varies according to several factors, such as the desired setpoint.

Example of operation in reheating mode:


Warning: Reheat Mode is possible but not recommended as it requires more hours of system operation. This can compromise long-term reliability and may call ambient thermal comfort into question (if the priority has been set for domestic hot water) or jeopardise efficiency (if the priority has been set for CA).


How can customers set the setpoint of the desired temperature of the tank in Reheat Mode?

There are two ways for customers to set the desired setpoint in Reheat Mode:

1) On the water temperature consultation screen. FYI, this screen only allows you to change the setpoint in Reheat Mode.

a. Actual temperature of the domestic hot water

b. Required temperature of the domestic hot water

2) In the menu [5.4] of MMI2 - Desired temperature in Reheat Mode.

How does the hourly programming + reheat function work?

It is a combination of the two functions described above: the system heats up at the scheduled time according to the defined setpoints (Comfort and/or Eco). However, when there is water consumption, the tank reheats to ensure the temperature remains at the reheat setpoint.

Tt = Tank temperature
t = Hour


Weather dependent setpoint 

Above we saw the three fixed setpoints that the customer can set: Comfort setpoint, Eco setpoint and Reheat setpoint.

In the advanced settings, the installer can set the Comfort setpoint to be weather dependent, rather than fixed:


Climate-dependent curve (WD curve) - explanation in the Operation Manual

Please consult the latest operation manual here.


When the weather-dependent option is active, the desired temperature of the tank is automatically determined based on the average outside temperature.


In hourly scheduling or time scheduling + Reheat Mode

  • The storage comfort temperature depends on the climate according to the

the climate-dependent curve. However, the Eco and reheating temperatures do NOT depend on the climate.


In Reheat Mode only

  • The desired temperature of the tank depends on the climate according to the climate-dependent curve and the customer cannot adjust the temperature.


How to establish when the system should give priority to the air conditioning or domestic hot water

Thermal comfort needs are more important in certain months of the year, so the system can be programmed with customer preferences on a month-by-month basis. The schedule can be changed at any time by the customer.


Warning: if the tank’s electrical heater always produces the thermal load for the domestic hot water because the priority is set to A/C, the electricity consumption is higher. It is important in these months to use the hourly scheduling of domestic hot water at times when A/C is not necessary. For example, at night or when no one is home.


What are the heating modes of the domestic hot water tank?

  • Efficient Mode:

The heat pump heats the water up to 50°C. Between 50°C and 70°C the electrical heater takes over. This has Energy Efficiency A rating (for both domestic hot water tanks).


  • Quick Mode:

Quick Mode has three different timer selections: 

1) Economical: electrical heater is triggered 30 minutes after heat pump.

2) Normal: electrical heater is triggered 20 minutes after heat pump.

3) Turbo: electrical heater is triggered 10 minutes after heat pump.


  • Powerful Mode:

Powerful Mode cannot be programmed. It is a special option to be used when hot water needs to be heated immediately. This option allows you to heat the water up to 50% faster than the Efficient Mode. It heats the water up to the Comfort setpoint. The electrical heater start sat the same time as the heat pump.


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