Thermomate 12V 5kW All-in-One Diesel Air Heater (Black) Review

If you want a diesel heater that is easier to install and manage than traditional split systems, the Thermomate 12V 5kW All-in-One Diesel Air Heater is designed to simplify the process. With the fuel tank and heater integrated into a single unit, it reduces installation complexity while still delivering strong heating performance.

This model is ideal for caravans, camper trailers, vans, motorhomes and even workshops. Running on diesel fuel and a 12V power supply, it provides a reliable off-grid heating solution without the need for mains electricity. :contentReference[oaicite:1]{index=1}

More Information

Table of Contents

• Why this heater is worth considering
• Main features
• Key specifications
• Who it suits
• Important points before you buy
• What is in the box
• FAQs

Why this heater is worth considering

The standout feature here is the all-in-one design. Unlike standard diesel heaters that require a separate fuel tank and more complex routing, this unit combines everything into a single housing. That makes installation faster and cleaner, especially in tight caravan or van layouts. :contentReference[oaicite:2]{index=2}

Performance-wise, the 5kW output delivers fast heat and is capable of warming medium to larger vehicle interiors quickly. The heater uses a high-grade aluminium heatsink to improve heat transfer, helping it reach temperature efficiently while maintaining steady output. :contentReference[oaicite:3]{index=3}

It also features automatic temperature control and remote operation, allowing you to set and maintain comfort levels easily—even from bed on cold mornings.

Main features

• All-in-one design with built-in fuel tank
• Powerful 5kW heating output
• 12V operation for off-grid use
• Diesel-powered for efficient running costs
• LCD control panel and remote control
• Automatic temperature regulation
• Fast heating with aluminium heatsink
• Quiet operation once temperature is reached
• Auto cool-down cycle for safety
• Compact and portable unit

Key specifications

Specification	Details
Brand	Thermomate
Model	TH-RVH6
Power	5kW
Voltage	12V
Fuel type	Diesel
Fuel tank	Approx. 5L (integrated)
Fuel consumption	0.21–0.51 L/hour
Noise level	Approx. 70–90 dB
Operating temperature	-40°C to +20°C
Remote range	Up to 30m

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Who it suits

This heater is ideal for:

• Caravan and camper trailer owners
• Van life and motorhome setups
• Off-grid travellers
• People wanting easier installation than split diesel heaters

It works particularly well for users who want a heater that can be installed quickly or removed later without major modification.

Important points before you buy

Although easier than standard diesel heaters, this unit still requires proper installation. You will need to:

• Install exhaust and air intake safely
• Connect to a 12V power source

The 5kW output may also be too powerful for very small vans. Running at low output for long periods can lead to carbon build-up, so correct sizing is important. :contentReference[oaicite:5]{index=5}

What is in the box

• All-in-one diesel heater unit (heater + tank)
• LCD control panel
• Remote control
• Wiring loom
• Air ducting and outlets
• Exhaust pipe and muffler
• Mounting hardware kit
• User manual

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Final thoughts

The Thermomate 12V 5kW All-in-One Diesel Heater is a smart choice for simplicity and flexibility. It offers strong heating performance while reducing installation complexity compared to traditional diesel heater setups.

For caravan and van users who want reliable, efficient, and portable heating, this model delivers excellent value—especially if ease of setup is a priority.

Frequently Asked Questions

What does “all-in-one” mean?

It means the heater and fuel tank are built into a single unit, simplifying installation and layout.

Does it require mains power?

No. It runs on diesel fuel and a 12V battery system.

How long can it run?

Up to around 18 hours depending on tank size and heat settings. :contentReference[oaicite:7]{index=7}

Is it easy to install?

Yes, easier than standard diesel heaters, but proper installation is still required.

Is it suitable for small vans?

It may be oversized for very small spaces. A lower output heater could be more suitable.