NIBE S2125 Air/Water Heat Pump User Manual

1 Important Information

For the latest version of the product's documentation, visit nibe.eu.

Installation Data

Accessories:

The serial number must always be provided. Certification that the installation is carried out according to instructions in the accompanying installer manual and applicable regulations.

Date: ______________________________ Signed: __________________________________________

Symbols

Explanation of symbols that may be present in this manual:

• [!] CAUTION! This symbol indicates danger to person or machine.
• [i] NOTE! This symbol indicates important information about what you should observe when maintaining your installation.
• [?] TIP! This symbol indicates tips on how to facilitate using the product.

Serial Number

The serial number can be found on the rear cover and at the bottom on the side of the unit.

[i] NOTE! You need the product's (14-digit) serial number for servicing and support.

2 Installation Function

An air/water heat pump installation uses the outdoor air to heat up a home. The conversion of the outdoor air's energy into residential heating occurs in three different circuits.

From the outdoor air (1), free heat energy is retrieved and transported to the heat pump. The heat pump increases the retrieved heat's low temperature to a high temperature in the refrigerant circuit (2). The heat is distributed around the building in the heating medium circuit (3).

Diagram Description:

The diagram illustrates the three main circuits:

• Circuit 1 (Outdoor Air): Outdoor air (e.g., 5°C) is drawn into the unit. A fan directs it to the evaporator. Here, the air releases thermal energy to the refrigerant, causing the air's temperature to drop before being expelled.
• Circuit 2 (Refrigerant): A refrigerant gas circulates in a closed system. In the evaporator, it absorbs heat from the outdoor air and boils. This gas is then compressed, increasing its pressure and temperature significantly (e.g., from 0°C to 80°C). The hot gas then flows to a condenser (heat exchanger), where it releases heat to the indoor module's heating medium, condensing back into a liquid. An expansion valve reduces the pressure, returning the refrigerant to its original temperature, completing the cycle.
• Circuit 3 (Heat Medium): The heat energy from the refrigerant in the condenser is transferred to the indoor unit's heating medium (water). This water is heated (e.g., to 55°C supply temperature) and circulates through a closed system to house radiators or heating coils. The indoor module also heats domestic hot water via an integrated charge coil.

Note: The temperatures shown are examples and may vary depending on installation and time of year.

3 Control of S2125

The S2125 is controlled in various ways depending on your system. You control the heat pump via your indoor module or control module. Refer to the Installer Manual for the specific indoor module/control module.

During installation, an installation engineer adjusts the necessary settings in the indoor module or control module to ensure the heat pump operates optimally within your system.

4 Maintenance of S2125

When your heat pump is located outdoors, some external maintenance is required.

Regular Checks

[!] CAUTION! Insufficient maintenance can cause serious damage to the S2125, which is not covered by the guarantee.

Checking Grilles and Bottom Panel on S2125

Check regularly throughout the year that the grille is not clogged by leaves, snow, or anything else. Be particularly vigilant during windy conditions and/or in the event of snow, as the grille can become blocked.

Check that the back of the unit is free from dirt and leaves. Also, check that the drain holes in the bottom panel are free from dirt and leaves.

Regularly check that condensation is routed away correctly through the condensation pipe. Ask your installer for assistance if required.

Diagram Description (Keep free of snow and ice):

• Prevent snow from building up and covering the grilles and drain holes on the S2125.
• Keep the unit free of snow and/or ice.

Cleaning the Outer Casing

If necessary, the outer casing can be cleaned using a damp cloth. Exercise care to avoid scratching the heat pump. Avoid spraying water into the grilles or sides, which could penetrate the S2125. Prevent contact with alkaline cleaning agents.

Actuating the Safety Valve (FL2)

The safety valve must be actuated regularly to remove dirt and check that it is not blocked. Also, ensure the vent valve is working.

In Event of Long Power Cuts

In the event of a prolonged power failure, it is recommended to drain the part of the heating system located outdoors. This is easier if shut-off valves are installed. Consult your installer if you are uncertain.

[i] NOTE! Also disconnect the non-return valve (RM1.2) to prevent the condenser from freezing.

Silent Mode

The heat pump can be set to "Silent mode," which reduces its noise level. This function is helpful when the S2125 is located in noise-sensitive areas. However, it should only be used for limited periods, as the S2125 might not achieve its full rated power.

Fan De-icing

This feature helps manage ice build-up on the fan, grille, and fan cone, which can cause abnormal fan noise.

• VVM S / SMO S: Menu 4.11.3 – Fan de-icing
• VVM / SMO: Menu 4.9.7 - tools

FAN DE-ICING: Setting range: off/on. Sets whether the "fan de-icing" function activates during the next "active defrosting." This is useful if ice/snow sticks to the fan, grille, or fan cone.

CONTINUOUS FAN DE-ICING: Setting range: off/on. An option for recurring de-icing, where every tenth defrosting cycle includes "Fan de-icing." This may increase annual energy consumption.

The "Fan de-icing" process heats the fan, grille, and fan cone using hot air from the evaporator (EP1).

Updating the Software

Information about updating software can be found in the Installer Manual for your indoor module or control module.

5 Disturbances in Comfort

In most cases, the indoor module/control module detects a malfunction (which can lead to discomfort) and indicates it with alarms and action instructions on the display.

[!] CAUTION! Work behind covers secured by screws may only be carried out by, or under the supervision of, a qualified installation engineer.

Troubleshooting

If an operational interference is not shown on the display, the following tips can be used:

Basic Actions

Start by checking the following:

• All supply cables to the heat pump are connected.
• Group and main fuses of the accommodation.
• The property's earth circuit breaker.
• The heat pump's fuse / automatic protection.
• The indoor module's/control module's fuses.
• The indoor module's/control module's temperature limiters.
• That the S2125 has no external damage.

Ice Build-up in the Fan, Grille, and/or Fan Cone

Set the "Fan de-icing" function in the indoor module/control module. For more information, see the section "Control Heat pump EB101" in the Installer Manual. If problems arise, contact your installer.

Water Below S2125 (Larger Amount)

• Fit accessory KVR to divert condensation from the air/water heat pump.
• Check that the water drainage via the condensation pipe (KVR) is working.

Contact Information

For countries not listed, contact NIBE Sweden or check nibe.eu for more information.