RV Repair by Custom way in California > FAQ > Installing diesel heater in a camper trailer
Installing diesel heater in a camper trailer

Installing diesel heater in a camper trailer

Installing a diesel heater in a camper trailer is one of the most effective upgrades for cold-weather travel. Diesel heaters are compact, fuel-efficient, and capable of keeping a small trailer warm even in freezing conditions. Unlike propane systems, they draw very little electrical power and can run for long periods without refueling.

Below is a clear, real-world overview of how diesel heater installation in a camper trailer works and what matters most.


Why diesel heaters are popular for camper trailers

Diesel heaters (often 2–5 kW units) are widely used in trailers because they:

  • consume minimal fuel

  • run on 12V power

  • produce dry heat (less condensation)

  • work reliably in cold climates

For off-grid camping and winter trips, they are often the most practical heating option.


Choosing the right heater size

Oversizing is a common mistake. Camper trailers have small interiors and do not need large heaters.

General guidance:

  • Small teardrop or compact trailer: 2 kW

  • Medium camper trailer: 2–3 kW

  • Large enclosed trailer: 4–5 kW (only if well insulated)

A correctly sized heater runs more efficiently and lasts longer.


Heater mounting location

Diesel heaters must be installed in a location that allows safe airflow, exhaust routing, and easy maintenance.

Typical mounting areas:

  • Under a bench or bed

  • Inside a cabinet with ventilation

  • Dedicated heater compartment

The mounting surface must be solid and heat-resistant.


Exhaust, intake, and fuel system

This is the most critical part of installation.

Proper setup includes:

  • Exhaust routed outside, away from doors and windows

  • Intake positioned to avoid dust and water

  • Fuel line protected from vibration and sharp edges

  • Secure mounting of the fuel pump at the correct angle

Improper exhaust routing is dangerous and should never be improvised.


Electrical requirements

Most diesel heaters use very little power once running, but startup current is higher.

Important electrical points:

  • Dedicated fused 12V circuit

  • Correct wire gauge

  • Stable battery capacity

Poor wiring is a common cause of heater errors and shutdowns.


Safety considerations

Safety must always come first when installing a diesel heater.

Essential precautions:

  • Carbon monoxide detector inside the trailer

  • Heat shielding near exhaust

  • Proper sealing of floor penetrations

  • Regular inspection of fuel and exhaust lines

Skipping these steps puts occupants at risk.


DIY vs professional installation

DIY installation is possible for experienced builders, but professional installation is strongly recommended if:

  • You are unsure about exhaust routing

  • The trailer has limited space

  • You plan to use the heater regularly or overnight

Mistakes with heaters are far more serious than cosmetic issues.


Diesel heater installation by Custom-way

For a safe and reliable setup, Custom-way provides professional diesel heater installation for camper trailers.

Custom-way focuses on:

  • correct heater sizing

  • safe exhaust and fuel routing

  • clean electrical integration

  • long-term reliability

This ensures dependable heat without safety concerns.

Installing a diesel heater in a camper trailer is one of the best upgrades for year-round camping. When installed correctly, it provides efficient, dry, and reliable heat with minimal fuel use. The key is proper sizing, safe routing, and attention to detail.

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