DH15 Hydronic Diesel Hot Water System with Belief 5kW Furnace


The unique DH15 Hydronic diesel hot water system provides fast hot water and optional air heating in the coldest of conditions in a super robust form.  Say goodbye to the hassles, risk (in boats) and cost of LPG and enjoy the benefits of hot water and air heating from one compact setup when free camping, sailing or off the grid. Powered by a 5kw Belief furnace, this is a compact economical diesel hot water system.


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SKU: DH15-BEL-RV Categories: , Tags: , ,


The DH15 replaces the DH12, Dieselheat’s most popular diesel hot water system, with super fast heat up time, the DH15 will provide a sink full of hot water or a continuous shower at 2.5L/min within 9-10 min of a cold start.

The reliable Belief diesel furnace is backed with a 2 year warranty and parts and service from Dieselheat. The Belief furnace is perfect for hot water only or occasional air heating recreational systems. For systems expected to use air heating a lot, live in or more commercial uses we suggest getting the DH15 with the Eberspacher D5E HS3 furnace.

The DH15 is sold pre assembled and tested for easy installation. The kit includes the Belief installation kit with wiring, fuel line, exhaust, inlet air silencer and on/off switch.

The DH15 has the following features

  • All 316 stainless steel, suitable for caravans and boats
  • Insulated dual skin tank retains heat for efficient operation
  • Compact design fits in tight spaces
  • Pre assembled and tested for easy installation
  • Fast heat up time, around 9-10min from cold
  • Integrated air heating (optional)
  • Includes Watermark approved tempering valve and plate heat exchanger to ensure hot water is always delivered at safe temperatures

Pair the DH15 with a Bricor Ultra Max low flow shower head to have super water wise showers – 0nly 2.5L/min, great for a caravan or boat where water is limited. Alternatively use the Bricor Elite shower head for a more luxurious 4-5L/min shower.

By adding in a Kalori fan head, the DH15 diesel hot water becomes an effective air heater, giving off up to 4kW of air heating from the single quiet Kalori Silencio 2 fan head.

Kits now include the high temperature silicon floor plate to get the exhaust through the floor with a dust/water proof seal.

System Performance

Time to useable hot water from cold start: 9min

Time to fully hot: 14min

Regeneration time between showers: 7min

Length of shower assuming 30 degree temp rise using Dieselheat shower heads:

Bricor UltraMax 2.5L/min @ 40PSI: >15min

Bricor Elite 4L/min @ 40PSI:   7min

Length of time the system can achieve a 30 deg temperature rise:

2L/min – >15min

3L/min – 13min

4L/min – 6min

5L/min – 3 min

These numbers are all affected by ambient temperature, installation layout and assume no concurrent air heating, so should be taken as a guide.

See here for more information on the DH Hydronic Series

The pre-assembled and tested hot water system kit includes:

  • insulated 15L hot coolant tank
  • Belief diesel hot water furnace
  • combustion air silencer
  • exhaust system
  • silicon exhaust floor plate
  • tempering valve
  • wiring loom
  • fuel pump and fuel line
  • on/off toggle switch

Note: the system is not shipped with coolant. The purchaser is required to fill the tank using a standard automotive corrosion resisting coolant mix.

Heat Power 5000(W)
Fuel Diesel
Rated voltage 12V/24V
Fuel Consumption 0.21~0.69(l/h)
Working temperature -40℃~+20℃
Dimensions 223*86*176(mm)

Useful Dimensions

Bare Tank including cap:

340W x 320H x 220D

Tank with tempering valve installed:

400W x 320H x 220D

Full system allowing for install brackets, furnace and plumbing fittings (required space):

450W x 320H x 340D

Note: Allow space or access above to fill the tank with colorant.

DH15 Installation Instructions

DH Hydronic Series Operator Manual 

Eberspacher D5E HS3 Technical Manual

All water heaters sold by Dieselheat carry 24 MONTHS warranty from date of purchase. Warranty is return to base which means you are responsible for returning any defective heaters to us for repair.

If you have an issue every attempt will be made to fix it via phone or email. Warranty is on heaters only and does not cover any issues caused by installations performed by the customer or other parties. If we can’t fix any issues with heater operation over the phone or email then the unit and possibly other parts as we suggest to you depending on the issue must be returned to us using an Australia Post air bag at your expense.

On arrival at our premises we will set the unit up on our test bench to ascertain what problem has occurred. Any defects or issues with the heater will be fixed free of charge and the unit will be shipped back to you at our expense. If the unit operates without any problems it will be deemed an installation problem and this is not covered by warranty. Any costs involved in returning the unit to the customer is at your expense.

Please do not try to disassemble the heater yourself whilst it is still under warranty without consulting with Dieselheat.

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