Truma DuoControl
Truma DuoControl is a safety gas pressure control system with automatic switching for connecting two gas cylinders in caravans and motorhomes. It ensures a constant outlet pressure of 30 mbar at an allowed inlet pressure of 0.6 – 16 bar.
View official manual on manufacturer's site ↗Technical Specifications
Master Troubleshooting & Diagnostics Matrix
| Error Code / Indicator | Symptom / Meaning | Possible Cause | Step-by-Step DIY Fix | Suggested Actions |
|---|---|---|---|---|
Status indicator is red (cylinder change / low pressure) | The pressure in the currently used cylinder has dropped below 0.5 bar, and the system has automatically switched to the reserve cylinder. | — | Check the connection to the empty cylinder, verify its fill level, and replace the empty cylinder with a full one. | DIY Safe |
Gas system leaking | A leak has been detected during the high-pressure or low-pressure leak test. | — | Immediately close the gas cylinder valve and have the gas system repaired by an authorized specialist; do not reopen the valve in the meantime. | Professional Intervention Required |
Problems with gas supply / Gas flow reduced or interrupted | Possible cylinder empty, closed valve, triggered reset button, or regulator icing at low temperatures around 0 °C. | — | Check there's gas in the cylinder and its valve is open, check the hose-rupture protection, make sure the changeover is set correctly, see whether the reset button has tripped, and check the quick-acting shut-off valves. If the regulator is freezing up, fit a Truma EisEx regulator heater. | DIY Safe |
Changeover display shows red | Gas extraction is taking place from the right-hand cylinder (reserve cylinder), indicating the operating cylinder is empty or pressure has dropped below 0.5 bar. | — | Check the connection to the left cylinder and the gas fill level, and replace or switch cylinders as needed. | DIY Safe |
Odor of gas or system leak detected | Possible gas leak in the system. | — | Don't switch on anything electrical or create any ignition source. Shut the cylinder valves straight away and keep them shut until a specialist has repaired the system. | Professional Intervention Required |
Black reset button sticking out (regulator not ready for operation) | The crash sensor or relief system has tripped or needs to be manually reset. | — | Use the T20 Torx pin kept on the housing's screw aid to push the black reset button in, then turn it gently anticlockwise. Check that it stays pushed in, and repeat if it doesn't. | DIY Safe |
Frequently Asked Questions
Q: Can I replace an empty gas cylinder without interrupting the operation of appliances?
Yes, DuoControl allows you to replace an empty gas cylinder with a new one while appliances continue to run. Integrated check valves prevent gas escaping if only a single cylinder is temporarily connected.
Q: When should pressure regulators and hoses be replaced?
Regulators and hose assemblies must be swapped for new ones within 10 years of their manufacture date (8 years if used commercially).
Q: Can the heating be operated while driving?
Yes, with a safety shut-off device like the Truma DuoControl CS and a properly sized gas installation, using liquefied gas heating while driving is permitted across Europe under Regulation (EC) No. 661/2009 and UN/ECE Regulation R 122.
Q: How do I reset the reset button?
Using the T20 Torx pin on the screw aid, push the black reset button into the housing and turn it gently anti-clockwise, making sure it stays locked in.
Q: Can gas appliances be operated while driving with the DuoControl?
No - the DuoControl has no built-in UN-ECE regulation 122 safety shut-off (crash sensor), so gas appliances mustn't be used in the vehicle while it's moving.