Support for the Fronius Ohmpilot

1. Press the button on the front of the Ohmpilot twice to activate the WLAN access point. The blue LED flashes twice repeatedly when the access point is open.
2. Connect your laptop / tablet / smartphone to the WLAN network called “Ohmpilot” that is now available (network key: 12345678).
3. Enter the following IP address in the address bar of your browser (e.g. Google Chrome): "192.168.250.181".

The communication between Ohmpilot and inverter can be established via a direct RS485 cable connection (Modbus RTU) or via a local network (Ethernet or WIFI):

Modbus RTU (RS485)

The bus cabling is done in parallel with the Fronius Smart Meter and the Fronius inverter or Data-/Hybridmanager. Please contact your installer for commissioning.

Ethernet / WLAN

The network configuration is done on the user interface of the Ohmpilot under "Network" (see: "Accessing the user interface of the Ohmpilot").

The inverter searches for the Ohmpilot and connects automatically as soon as both components are in the same network. The search process may take up to 5 minutes. When using subnets, both components must be in the same subnet.

Please contact your installer for commissioning.

After the first commissioning of an Ohmpilot, the inverter and the Ohmpilot automatically connect to each other. However, after a component has been replaced (e.g. in the course of a service case), the connection must be established manually.The procedure depends on the inverter you have:

Fronius SnapINverter (Symo, Symo Hybrid, Primo, Eco)

1. Access the user interface of the SnapINverter (Data-/Hybridmanager). The procedure is described here: “Accessing the user interface of the SnapINverter via WLAN“ or “Accessing the user interface of the SnapINverter via Ethernet”.To proceed, the setup wizard must have been fully completed. If the setup wizard opens automatically when you visit the user interface, complete it first.
2. On the user interface of the SnapINverter (Data-/Hybridmanager) go to "System information".
3. Under “Components” next to the Ohmpilot click on “Pairing”.

Fronius GEN24

1. Access the user interface of the inverter. The procedure is described here:“Accessing the user interface of the SnapINverter inverter via WLAN“ or “Accessing the user interface of the inverter via Ethernet”.To proceed, the setup wizard must have been fully completed. If the setup wizard opens automatically when you visit the user interface, complete it first.
2. On the user interface of the inverter go to "Device Configuration" --> "Components".
3. Click on “Add component” --> “Ohmpilot” and add your Ohmpilot.

Your excess PV power is fed into the grid instead of being used by the Ohmpilot as heating power? Learn what steps can be taken to resolve this problem:

Press the button on the front of the Ohmpilot 3x to activate the boost mode. In boost mode, the dimmer level (L1) is at 100% and L2 and L3 are switched through. In boost mode, the Ohmpilot operates your heating system at maximum power.

After 4 hours or by pressing the button again once, boost mode is deactivated.If the Ohmpilot does not power the heating element even in boost mode, this can be due to the following reasons:

Neutral wire not connected

When using a three-phase heater, the neutral conductor must be implemented. The heating element must be connected in a star connection. If your heating element does not have a neutral conductor, it must be retrofitted.

Temperature switch of the heating element

Check whether the temperature switch of your heating has tripped. As a test, turn the maximum temperature to the highest possible setting and restart the boost mode.

Heating element not compatible

Single-phase heating elements can be operated from 0.3 to 3 kW and three-phase heating elements from 0.9 to 9 kW.Use only purely resistive loads (no electronic temperature limiters, fans, ...).In three-phase heating elements the load must be divided equally between all 3 phases (e.g. 3x 3kW).

If the Ohmpilot outputs the full heating power in boost mode, but does not heat in normal operation, this can be due to the following reasons:

Maximum temperature setting

On the user interface of the Ohmpilot under "General", check whether you have set the maximum temperature too low, preventing any heating (see: "Accessing the user interface of the Ohmpilot").

No communication between Ohmpilot and inverter

Check the data connection between the Ohmpilot and the inverter. Note the points "Setting up the data connection between the Ohmpilot and the inverter" and "Manually pairing the inverter with the Ohmpilot". We recommend setting up the communication via Modbus RTU (RS485).

The following causes can lead to the Ohmpilot drawing power from the grid:

Legionella protection / temperature switch

The temperature switch of the heating element and the temperature sensor of the Ohmpilot (if installed) measure different values depending on their position. If the legionella protection of the Ohmpilot is active, but the maximum temperature set on the temperature switch of the heating element is too low, the Ohmpilot cannot heat to the required 60°C. In this case, the Ohmpilot tries repeatedly to reach 60°C every several hours, which can lead to power being drawn from the grid. To solve this problem, increase the maximum temperature on the heating element temperature switch.

Minimum temperature setting

Check your settings of the day curve on the user interface of the Ohmpilot under "General". The Ohmpilot tries to keep the set minimum temperature for the entire set period, which can lead to electricity being drawn from the grid (see: "Accessing the user interface of the Ohmpilot").

Incorrect Fronius Smart Meter values

The inverter sends the Ohmpilot the value of the desired heating output power based on the measurement values of the Smart Meter. If the smart meter delivers incorrect values (e.g. due to a faulty installation), the control of the Ohmpilot is also incorrect. Check in Solar.web whether the values of the grid feed-in and the grid consumption are plausible and consistently available for your system. If there is a problem with these values, please contact your installer to check the smart meter.

A firmware update of the Ohmpilot can only be carried out via Solar.web.

Instructions on how to proceed can be found here: “Firmware update via Fronius Solar.web”. 

A problem was detected with switching a phase relay (L2 or L3). This can likely mean a hardware fault of the Ohmpilot.

Please contact your installer.

Legionella protection was activated on the user interface of the Ohmpilot, but the required 60°C could not be reached.

If you activated an external source on the Ohmpilot (e.g. gas-fired heating), make sure it is switched on. If no external source is used, check whether the temperature switch of your heating element is set too low.

Also, make sure that the Ohmpilot's temperature sensor is installed correctly in the boiler (above the heating rod).

A day curve was set on the user interface of the Ohmpilot, but the set minimum temperature could not be reached.

If you activated an external source on the Ohmpilot (e.g. gas-fired heating), make sure it is switched on.

If no external source is used, check whether the temperature switch of your heating element is set too low.

Also, make sure that the Ohmpilot's temperature sensor is installed correctly in the boiler (above the heating rod).

Set up the data connection between the Ohmpilot and the inverter via Modbus RTU or Ethernet / WLAN (see: “Setting up the data connection between the Ohmpilot and the inverter”).

Make sure that Ohmpilot and inverter are paired with each other (see: ”Manually pairingthe inverter with the Ohmpilot”).