For one 2 kW-class diesel/gas air heater, the supplied steady operating values are 1.25–2.45 A and 14–29 W at 12 V DC. These are planning values for the bound example, not universal specifications for every diesel heater.

The range covers steady operation—not the ignition peak. The glow pin draws more power briefly during startup, but no startup current or wattage is supplied here. Treat startup draw as unknown, not zero.

This lookup also does not produce a direct generator-size result because the heater is a 12 V DC load: the generator powers the converter/charger, not this load directly. Check your exact heater's startup requirement before deciding whether a battery, converter, charger, or other 12 V source is adequate.

What this diesel-heater lookup includes

This lookup covers:

  • Heater class: one diesel/gas air heater in the 2 kW output class
  • Quantity: one heater
  • Electrical supply: 12 V DC
  • Steady operation: 1.25–2.45 A and 14–29 W
  • Ignition or glow-pin startup: higher than steady operation, but no numerical value is supplied

The 2 kW label describes the heater's heat-output class. It does not mean the heater consumes 2,000 W of electricity. Its supplied steady electrical range is 14–29 W at 12 V DC.

The current and wattage ranges are reproduced as supplied; they should not be treated as exact endpoint conversions from one another. There is also no single typical or average value within either range. Use them for class-level planning only unless you have electrical data for your exact model.

Why this is not a direct generator load

The decisive constraint is the supply type: this heater requires 12 V DC, while the generator-facing side of the RV system supplies the converter, charger, or another suitable DC power supply. For this lookup, the result is a 12 V DC load: the generator powers the converter/charger, not this load directly.

We therefore cannot determine generator size from the heater's DC running watts alone. The AC demand seen by a generator depends on the converter or charger's input characteristics and the other RV loads operating at the same time.

Do not connect a 12 V heater directly to an AC generator output. Follow the heater and RV power-system instructions for the required DC supply and connection method.

Using the amps and watts for battery and DC-source planning

Use the supplied values in these ways:

  1. Use amperes to check the 12 V side. Compare the heater's running current and model-specific maximum or glow-pin current with the ratings of the battery system, DC power supply, and heater circuit.
  2. Use watts to identify steady operating power. The supplied range is 14–29 W at 12 V DC, but it does not establish startup capacity, energy use, or runtime.
  3. Include simultaneous 12 V loads. If lights, fans, pumps, or other equipment must operate with the heater, their demand also matters.
  4. Schedule optional loads when practical. Loads that do not need to run together can take turns, reducing simultaneous demand. This does not remove the need to support the heater's ignition peak.

This page does not check a particular battery, converter, charger, inverter, fuse, connector, or wire size. It also does not calculate battery runtime or the converter's AC input.

Why running watts are not daily energy

Watts (W) describe power at an operating moment or state. Watt-hours (Wh) describe energy used over time.

The 14–29 W running range cannot be presented as daily energy because no operating duration, duty cycle, or modulation schedule is supplied. Daily or trip energy requires a defensible schedule showing how long the heater spends in each operating state.

This lookup supplies no measured daily consumption, Wh/day, Ah/day, or guaranteed battery runtime. To estimate trip energy, first determine your expected operating hours and obtain supported model-specific information about how the heater cycles or modulates.

Check the rating for your heater

For a model-specific answer, find the exact model number and check:

  • The heater nameplate or electrical label
  • The installation and operating manual
  • The controller documentation
  • The manufacturer's electrical data
  • The specified maximum or glow-pin startup current
  • The manufacturer's fuse and wiring instructions

Look specifically for 12 V current in amperes during normal operation and startup. A maximum-current specification is especially important because the supplied 1.25–2.45 A range does not include a numerical ignition peak.

If startup draw is not published, keep it marked unknown. Do not substitute the 2 kW heat-output label, assume startup equals running draw, or treat a missing value as zero.

Plan the generator-facing RV load

First, use your heater's model-specific DC ratings to check the 12 V system. Then size the generator around the AC equipment it actually powers: the RV converter or charger plus the other simultaneous AC loads.

Use the RV Generator Size Calculator for that broader system-level plan. If you need help distinguishing continuous demand from a short startup surge, review the running-versus-starting-watts guide. Its worked appliance figures are separate examples and should not be transferred to this heater.

This lookup is a planning estimate, not a measurement, guaranteed runtime, validated electrical dispatch, or approval of a particular installation.