VarioHeat Comfort
Truma VarioHeat wiring diagram
European VarioHeat comfort: 12 V propane/butane heater at 30 mbar, up to 3.7 kW gas heat. Electrical draw is 0.65 / 2.75 / 5.4 A across its stages. Requires a dedicated protected supply and controlled fan run-on; this version is not approved for boats.
- Compatible systems
- 12 V
- Rated power
- 65 W
- Continuous draw
- 5.4 A
Wiring diagram
How the VarioHeat is wired.
Open this example in Crimp to use your own parts and cable lengths. Review the assumptions and installation notes as you adapt the circuit.
Cable sizing for this example
Use the diagram as a starting point for your installation. Replace the example equipment and cable lengths with your own, and check the connections against your exact model's instructions.
3 m one way
12 V system
- Wire
- 2.5 mm² · 13 AWG
- Example fuse
- 7.5 A
- Design current
- 5.4 A
- Voltage drop
- 1.9%
Sized against ABYC E-11. The design current is the part's continuous draw. The length is one way; voltage drop includes an equal-length return.
Run-length and manufacturer assumptions
The editable example uses 3.048 m (10 ft) runs unless a shorter run is stated. Metric overviews round these to 3 m. Adapt the parts and lengths to your installation before choosing cable and protection.
Supporting parts
- 6.1 m total of 2.5 mm² (13 AWG) marine cable
- Terminations for 2.5 mm² cable, matched to the equipment's screw terminals, leads or studs
- 7.5 A fuse and holder on the positive run
- Heat-shrink, strain relief and terminal boots sized to the cable
Check stud sizes, fuse type, run length and how warm the space gets against the gear you actually have before you order.
Installation notes
Before you install.
Open a question for model-specific guidance and sources.
Verified against the manufacturer's documentation (rev. 39050-00071 · 01 · 10/2017), checked 2026-10-01. Manufacturer documentation →
Identify the European Comfort heater
This walkthrough covers VarioHeat comfort, 12 V, propane/butane at 30 mbar. Its three heat stages are 1.3, 2.8 and 3.7 kW. The matching Truma operating instructions, printed page 15, list electrical consumption of 0.65, 2.75 and 5.4 A. Heat output is gas energy, not a 3700 W battery load. The North American Comfort US and the lower-output eco need their own manuals.
Follow the harness, not just two canvas pins
Installation pages 18–19 identify X5-1 as battery positive and X5-2 as battery negative. X6 connects the Truma control panel; X7 handles the room sensor and, where needed, the window interlock. The canvas shows only the power feed, so it does not document those controls or prove the heater is ready to run.
Use the matching supplied connectors, protect cables from chafing, and keep wiring away from hot ducts and exhaust. Installation and commissioning include gas, exhaust and combustion-air work and belong with a suitably qualified installer.
Protect a dedicated supply
Printed page 19 specifies a dedicated 10 A protected supply and two 2.5 mm² conductors, increasing to 4 mm² when the stated length exceeds 6 m. Check voltage drop along the installed route. No other consumers share this supply. For direct battery connections the manual also specifies protection in both lines; have the installer reconcile this with the vehicle's grounding arrangement.
The appliance's internal F1 is a 10 A quick-acting fuse, identified separately in operating page 14. It does not replace protection for the external cable, and replacement is service work.
Shut down through the controls
Switch the heater off at its control panel and allow residual-heat fan operation to finish before isolating its supply. Reserve battery capacity for that run-on. For troubleshooting, inspect supply voltage under blower load, gas availability, unobstructed outlets and the displayed fault code before repeatedly resetting it.
The reviewed European instructions exclude boats and other watercraft. Follow the approved exhaust/cowl, clearances and interlock arrangement for the vehicle rather than treating this electrical entry as a complete heater installation design.
Fit check
Connect it to the rest of your system.
Describe your setup to draft a system with VarioHeat Comfort connected. Review the selected parts and cable lengths, then edit the diagram in Crimp.
The model only picks parts and draws the connections. Every wire size and fuse rating still comes from Crimp's own sizing, never from the model.
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Technical reference
Specifications and terminal map.
Check the model, ratings and connection points against your own unit before choosing installation hardware.
Catalog specification
European VarioHeat comfort: 12 V propane/butane heater at 30 mbar, up to 3.7 kW gas heat. Electrical draw is 0.65 / 2.75 / 5.4 A across its stages. Requires a dedicated protected supply and controlled fan run-on; this version is not approved for boats.
- Compatible systems
- 12 V
- Rated power
- 65 W
- Continuous draw
- 5.4 A
Terminal map
Catalog connection points, current direction and planning limits. Check the manufacturer's pinout and connector ratings before installation.
+
positive · input
−
negative · input
Sources and sizing method
Equipment specifications. Model details, ratings and terminal roles come from the catalog. Check your unit’s label and current manufacturer documentation for its exact revision.
Example sizing. Sized against ABYC E-11. Boats built to UK or EU rules answer to ISO 13297 — check these figures against it before you build. Results use the example current and run length shown above. Set your actual equipment, lengths and installation conditions in Crimp before choosing hardware.
Read how the sizing worksNext step
Plan your installation with VarioHeat.
Open this example as a new project, or add this component to your existing diagram. Use your equipment and cable lengths to review the sizing.
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