Truma FrostControl
The Truma FrostControl is a currentless overpressure safety and drain valve featuring an integrated frost monitor function for Truma hot water systems (Boiler or Combi) and permanently installed water tanks. It automatically drains the boiler contents when ambient temperatures drop below approximately 3 °C to prevent frost damage, and relieves system overpressures up to 4.5 bar.
Technical Specifications
Weight Kg200 g (flexible hoses version) / 250 g (fixed pipe version)
Master Troubleshooting & Diagnostics Matrix
| Error Code / Indicator | Symptom / Meaning | Step-by-Step DIY Fix | Suggested Actions |
|---|---|---|---|
Operational Fault | Temperature at the drain valve is below approx. 3 °C, causing it to open automatically. | Switch on the vehicle heater if necessary. Once temperatures at the drain valve rise above approx. 7 °C, it can be closed again. | DIY Safe |
Operational Fault | Temperature at the drain valve is below approx. 7 °C, or the rotary switch is not set to 'Operation'. | Switch on the vehicle heater to raise the temperature above approx. 7 °C, then turn the rotary switch to 'Operation' and press the pushbutton until it engages. | DIY Safe |
Operational Fault | Water pressure is too high. | Check pump pressure (max. 2.8 bar). If connected to a central water supply (rural or city connection), a pressure reducer must be used to prevent pressures higher than 2.8 bar from occurring in the boiler. | DIY Safe |
Frequently Asked Questions
Q: At what temperature does the FrostControl automatically open?
The FrostControl automatically opens at ambient temperatures below approximately 3 °C at the valve.
Q: When can the FrostControl be closed again after automatic or manual drainage?
The drain valve can only be closed manually and the boiler filled when the temperature at the drain valve is above approximately 7 °C.
Q: What is the maximum pump pressure and system pressure allowed?
The maximum pump pressure is 2.8 bar, and the maximum system overpressure is 4.5 bar.