Stay Comfy in Your OP4

Your OP4 off-road camper is designed to keep you comfortable no matter the weather, thanks to the optional Truma VarioHeat propane furnace and Dometic Cool Cat 10,500 BTU A/C-heat pump. This detailed guide walks you through setup, operation, safety, troubleshooting, and maintenance—ensuring you enjoy all-season camping with confidence. Let’s dive into keeping your OP4 a cozy or cool haven!

Overview of Heating and Cooling Options

Your OP4 comes equipped with two optional systems to suit your camping needs:

• Truma VarioHeat (16,000 BTU Propane Furnace): Provides powerful warmth for cold nights, using propane from your 20-lb gas bottle.
• Dometic Cool Cat (10,500 BTU A/C-Heat Pump): Offers cooling for hot days and mild heating, requiring 120V shore power or a generator.

Both systems are designed for recreational use and enhance your OP4’s versatility, but proper setup and care are key to safety and performance.

Setting Up and Operating the Truma VarioHeat Furnace

Initial Setup

• Location: The furnace is typically installed in the floor well or under a bed, with vents near the ceiling or floor (check your manual’s layout).
• Propane Connection: Ensure your 20-lb propane bottle is securely mounted in the gas bottle holder. Connect the regulator and pigtail to the quick connect, then link to the furnace (see Gas System Guide for details).
• Ventilation: Open a window or roof vent slightly to allow air circulation, as required for safe propane use (Page 35: "Life & Fire Safety" emphasizes ventilation to prevent CO buildup).

Turning On the Furnace

1. Power On: Ensure the control panel’s red key is turned on and the 12V battery system is charged (above 12.2V).
2. Ignition: Turn the thermostat dial to your desired temperature (e.g., 60°F). The furnace will automatically ignite, and you’ll hear a click as the burner starts.
3. Fan Operation: The built-in fan will circulate warm air; adjust the vent direction for even heating.

Turning Off the Furnace

• Rotate the thermostat dial to the “Off” position. Wait 2-3 minutes for the fan to cool down before closing vents.
• Safety Step: Turn off the propane valve at the bottle after use to prevent leaks (Page 35 recommends this to reduce CO risks).

Performance Tips

• Heat Output: Delivers 16,000 BTU, sufficient for the OP4’s 21 ft 4 in x 6 ft 10 in interior. Expect 10-15 minutes to reach set temperature.
• Fuel Efficiency: A 20-lb propane tank lasts approximately 20-25 hours at medium settings.
• Altitude Adjustment: At high elevations (above 10,000 ft), the flame may weaken.

Setting Up and Operating the Dometic Cool Cat A/C-Heat Pump

Initial Setup

• Power Requirement: Connect to a 120V, 30 Amp shore power source using the exterior hookup (driver’s side) or a generator (minimum 2200W).
• Installation: The unit is roof-mounted; ensure the interior vent and digital thermostat are accessible (usually near the control panel).
• Ventilation: Keep the exterior condenser clear of debris for efficient airflow.

Operating the Cooling System

1. Power On: Turn on the main circuit breaker and the A/C breaker on the control panel.
2. Thermostat Settings: Set the digital thermostat to “Cool” mode and select your temperature (e.g., 75°F). The compressor will start, and cold air will flow within 5-10 minutes.
3. Fan Speed: Choose low, medium, or high fan settings based on your comfort needs.
4. Condensation: A drip tray under the unit collects moisture—empty it if camping in high humidity.

Operating the Heat Pump

• Switch the thermostat to “Heat” mode (effective above 40°F outdoor temperature).
• Set your desired temperature; the heat pump uses reverse-cycle technology for mild warmth.
• Limitation: Not a primary heater—use the Truma furnace for colder conditions.

Shutting Down

• Turn off the A/C breaker and thermostat. Disconnect shore power if moving camp.
• Storage Prep: Remove the exterior cover (if installed) and store indoors to prevent weather damage (Page 35 notes the importance of proper storage to avoid hazards).

Performance Tips

• Cooling Capacity: 10,500 BTU cools the OP4 in 15-20 minutes on a 90°F day.
• Power Usage: Approximately 10-12 Amps on high; monitor battery charge if using a generator.
• Maintenance: Clean the condenser fins annually with a soft brush to maintain efficiency.

Safety Considerations (Inspired by Page 35: Life & Fire Safety)

Your safety is paramount when using heating and cooling systems. Here’s how to stay protected:

• Propane and CO Safety: The LP/CO detector (wired to the 12V system) alerts you to propane or carbon monoxide levels. Test it monthly by pressing the test button (Page 35). If it alarms, ventilate immediately, turn off the propane valve, and evacuate.
• Smoke Alarm: Located near the door, it detects smoke from any source. Replace the battery annually or if it chirps.
• Fire Extinguisher: Keep the extinguisher (inside the door) accessible. Use it for small fires—aim at the base and sweep side to side. Call emergency services if unsure.
• Emergency Exits: In case of fire or gas hazard, use the main door or unzip the bed-end panels (bottom flap for quick escape, per Page 35).
• No Indoor Flames: Avoid using open flames (e.g., candles) with the furnace on to prevent fire risks.
• Ventilation: Always keep a window or vent open during propane use to avoid CO buildup (Page 35 warns of potential injury or death from poor ventilation).

Troubleshooting Common Issues

• Furnace Won’t Ignite:
  • Check propane level and valve (open fully).
  • Ensure the thermostat is reset and battery voltage is above 12.2V.
  • Listen for clicks—contact us if no ignition after 3 tries.
• Insufficient Heat:
  • Clear vents of obstructions.
  • Adjust thermostat; low propane or high altitude may reduce output.
• A/C Not Cooling:
  • Verify 120V power and breaker status.
  • Clean condenser fins; ensure no debris blocks airflow.
  • The A/C is not capable for climate controlling the interior of the OP4 camper, it is designed to provide some cooling and comfort at the end of the day, to prepare the cabin area for a more comfortable sleeping experience.
• Heat Pump Ineffective:
  • Check outdoor temperature (below 40°F disables heat mode).
  • Switch to the Truma furnace for colder weather.
• Error Codes: Refer to the thermostat manual for specific codes (e.g., E1 for power issues).

Maintenance and Care

• Truma VarioHeat:
  • Annual Service: Have a certified technician inspect the burner, heat exchanger, and exhaust.
  • Fuses: Replace the 5A fuse if the unit fails (located near the control panel).
  • Vents: Clean with a vacuum or compressed air to remove dust.
• Dometic Cool Cat:
  • Filter Cleaning: Remove and wash the interior filter monthly with mild soap.
  • Condenser Care: Brush fins gently every year; avoid high-pressure water.
  • Storage: Cover the unit or remove it for long-term storage to prevent corrosion.
• General Tips:
  • Inspect all connections (propane, electrical) before each trip.
  • Store both units dry and powered off to extend lifespan.

Winterizing for Storage

• Furnace: Drain any condensate from the exhaust line. Store the propane bottle outside the camper.
• A/C-Heat Pump: Remove the cover, clean thoroughly, and store indoors. Disconnect all power to prevent battery drain.
• Safety Check: Test the LP/CO and smoke alarms before storing to ensure they’re functional for the next season.

Why It Matters for Your Adventure

Proper use of your heating and cooling systems keeps you safe and comfortable, reducing the chance of issues that could dampen your trip. At Opus Camper USA, we’re committed to your satisfaction—follow these steps to maintain your OP4 and share your adventure stories with us!

Get Help

Have questions or need support? Contact us at 925.215.7315 or info@opuscamper.us. We’re here to ensure your OP4 remains your perfect camping companion!