122R-000449 | Genuine Eberspacher® Hydronic Water Heater 12V Kit

• Fuel: Diesel
• Voltage: 12V
• Heat output: 17,000 BTU (5 kW)
• Fuel consumption: 0.03 - 0.15 gal/h (0.15–0.59 L/h)
• Power consumption: 5 - 32 W
• Max operating altitude: 9,900 ft (3,000 m)

1. No engine idling (big one)

• Heats the cab & sleeper with the engine off

• Saves a lot of diesel

• Avoids no-idle fines

• Cuts engine wear

2. Cold-weather engine protection

• Heats engine coolant

• Makes cold starts easier

• Reduces engine damage in freezing temps

• Faster warm-up = less smoke and stress

3. Comfort while parked

• Quiet, steady heat all night

• More even warmth than air heaters

• Great for sleeper berths in winter

4. Multi-use heat source

One system can:

• Heat the cab

• Warm the engine

• Sometimes provide hot water (custom setups)

5. Lower operating costs

• Burns far less fuel than idling

• Extends engine life

• Pays for itself over time (especially for long-haul)

6. Works in extreme conditions

• Reliable in very cold climates

• Used by emergency vehicles, oilfield trucks, heavy equipment

1. No heat or weak heat

• Cab/sleeper stays cold

• Takes way longer to warm up than normal
   Often: glow plug, fuel delivery, or coolant circulation issue

2. Heater starts then shuts off

• Fires up, runs a few minutes, then stops

• Repeated restart attempts
   Flame sensor, overheat fault, low voltage, or clogged fuel screen

3. Fault codes or blinking lights

• Controller shows error codes

• Rapid blinking LED on the unit
   The heater is protecting itself—don’t ignore this one

4. Strong diesel smell or white smoke

• Excess fuel smell

• White smoke from exhaust
   Incomplete combustion, bad glow plug, or carbon buildup

5. Loud clicking, whining, or unusual noise

• Fuel pump clicking much louder than normal

• Grinding or squealing
   Failing pump, air in fuel line, or worn fan

6. Coolant leaks

• Wet spots under truck

• Sweet smell in the cab

• Low coolant level
   Hose, fitting, or internal heat exchanger leak

7. Overheating or shutdowns

• Unit overheats and trips off

• Fan keeps running after shutdown
   Coolant flow problem (bad circulation pump or airlock)

8. Battery drain

• Heater won’t start unless engine is running

• Low-voltage shutdowns overnight
   Weak batteries, poor wiring, or heater drawing too much power

9. Soot buildup at exhaust

• Black soot around heater exhaust
   Poor combustion—common if maintenance is overdue

10. Works sometimes, not others (intermittent)

• Works one night, fails the next
   Electrical connections, sensors, or control module issues