User Manual for Danfoss RAS-C2 Radiator Thermostat Combi Pack

Quick Guide: Installation and Troubleshooting

The Danfoss RAS-C2 is a bi-directional radiator thermostat designed for easy installation. If you encounter water hammer (a knocking noise in the pipes), you can adjust the flow direction using the setting ring on the valve without removing the valve from the system. Simply turn the setting ring to the alternative setting shown in the diagrams.

Valve Installation

The valve is bi-directional and can be installed horizontally or vertically in either the flow or return pipe. To install:

• Close all radiator valves by turning the valve cover cap clockwise.
• Allow the system to cool down.
• Start the boiler or heating system.
• Open one valve and determine the flow direction by checking which pipe heats up first.
• Remove the cap and turn the setting ring according to the flow direction drawings. The setting ring should be turned by hand only.
• Repeat these steps for all valves until set correctly.

We recommend using a flat-faced adjustable spanner and a soft cloth to protect the chrome surfaces when tightening connections.

Fitting the Sensor

Once the valve is installed, follow these steps to fit the sensor:

1. Remove the cap from the valve and turn the sensor to the frost protection setting.
2. Ensure the union nut is turned loosely up towards the sensor body until it is only slightly free of the lower part of the sensor body.
3. Press the sensor firmly onto the valve. Ensure the scale pointer is at the top for horizontal mounting, or at the front for vertical mounting.
4. While holding the sensor firmly on the valve, secure the connection by turning the union nut clockwise by hand.
5. Fully tighten the grey union nut using parrot nose pliers while still holding the sensor firmly in place.

Temperature Settings and Usage

The desired room temperature is set by turning the sensor head. The thermostat senses the air temperature around it and regulates the water flow accordingly. To ensure proper operation, never cover the thermostat with curtains, furniture, or other obstructions.

Positive SHUT-OFF feature: The head can be turned past the frost protection setting (a slight resistance will be felt) to setting "0", at which point the water flow is shut off completely. This allows the radiator to be drained and removed for maintenance or decoration.

Note: Thermostatic Radiator Valves (TRVs) do not control the boiler. If the whole house is warm, the TRV cannot turn off the boiler; a separate room thermostat is required for that purpose.