Short Answer
A diesel parking heater burns a small amount of diesel outside the engine, transfers the heat to the vehicle cabin through a heat exchanger, and blows warm air in — all while the engine is switched off. This lets you start the day in a warm cab without idling the engine, saving fuel, reducing engine wear and cutting emissions. A typical 5kW heater warms a truck sleeper in 15 minutes on a cold morning and uses less than 0.5 liters of diesel per hour.
The Four-Step Cycle
Understanding how the heater works makes installation, maintenance and troubleshooting far easier. Every parking heater follows the same four-step cycle: pre-heat, ignition, stable combustion and cool-down. The control unit times each step and monitors temperature, flame and voltage throughout.
Step 1 — Pre-heat. When you press the power button, the control unit runs a self-check on the blower, fuel pump, glow plug and temperature sensors. The ceramic glow plug heats to 850°C within a few seconds. The blower starts at low speed to purge the combustion chamber.
Step 2 — Fuel injection and ignition. The metering pump delivers a precise pulse of diesel into the combustion chamber. The fuel hits the hot glow plug, vaporizes, and ignites. The flame sensor confirms ignition within about 30 seconds. If ignition fails three times, the heater shuts down and stores a fault code.
Step 3 — Stable combustion. Once lit, combustion continues in a swirl chamber. Hot gases flow through a finned heat exchanger. The cabin blower draws cold air across the outside of the heat exchanger and blows warmed air into the cab. Combustion gases exit through a separate exhaust pipe outside the vehicle; they never mix with cabin air. The thermostat modulates fuel delivery to hold the set temperature.
Step 4 — Cool-down. When you switch off, fuel injection stops but the blower keeps running for 60 to 90 seconds to cool the glow plug and heat exchanger. This protects components from heat damage. Never disconnect the battery during cool-down.
Why It Saves Fuel
A parking heater consumes about 0.1 to 0.5 liters of diesel per hour, compared with 1 to 3 liters per hour of idling a diesel truck engine for heat. Over a winter season, long-haul drivers save hundreds of liters of fuel. It also reduces cold-start engine wear: experts estimate that a cold start at −10°C causes as much engine wear as several hundred kilometers of highway driving.
Is It Safe?
Yes, when installed correctly. The combustion air, exhaust and cabin air are three completely separate circuits. The heater carries overheat protection, flame-out shutdown and low-voltage shutdown. Our heaters are certified to EU 2015/1188 and EU 2015/1186. The remote-control version carries FCC ID 2BOWN-CY-001 for the U.S. market.
Common Questions
Will it drain my battery? Typical draw is 1 to 5 amps at 12V. A healthy 100Ah battery can run the heater for 8 to 12 hours on low. Always start the engine and drive for 30 minutes after overnight use.
Can I use it while driving? Yes, but most drivers use it when parked. Running it while driving provides supplemental heat and reduces engine load on the heater core.
What kind of diesel does it use? Standard summer diesel above +5°C and winter or arctic diesel below that. Never use kerosene mixed above 30 percent; it reduces fuel lubricity.
How loud is it? 35 to 55 dB at one meter, depending on fan speed. On low, most people sleep through it.
References
[1] European Union Regulation (EU) 2015/1188 on monitoring and reporting of CO2 emissions from light commercial vehicles.
[2] European Union Regulation (EU) 2015/1186 on type-approval requirements for motor vehicles and engines regarding emissions.
[3] SAE International J1455: Recommended Environmental Practices for Electronic Equipment Design in Heavy-Duty Vehicle Applications.
[4] FCC Part 15 Subpart C: Intentional Radiators, U.S. Federal Communications Commission.
[5] ISO 6722: Road vehicles – 60 V and 600 V single-core cables.
[6] U.S. EPA Idling Reduction Fact Sheet for Heavy-Duty Diesel Vehicles.
[7] ISO 8820-2: Road vehicles – Time-lapse current-limiting fuses.
