Introduction
This manual provides essential information for the safe and efficient operation of your Optimus Instant Water Heater, Model OI-05 B Gas L.P. This appliance is designed to provide continuous hot water on demand, offering efficiency and convenience for a single service point. Please read these instructions thoroughly before installation and use, and retain them for future reference.
Key features include continuous hot water flow, automatic ignition upon hot water demand, and compatibility with both high and low water pressure systems.
Safety Information
Important Safety Instructions:
- Installation must be performed by a qualified professional in accordance with all local codes and regulations.
- Ensure adequate ventilation for the appliance to prevent carbon monoxide buildup.
- Do not store flammable materials near the water heater.
- Regularly inspect gas connections for leaks. Use a soapy water solution, never an open flame.
- Do not block the exhaust vent.
- Keep children and pets away from the appliance during operation.
- In case of gas odor, immediately shut off the gas supply, open windows, and contact a qualified technician.
Product Overview
The Optimus OI-05 B is an instant water heater designed for indoor installation, providing hot water for one service point. It operates on LP (Liquid Propane) gas and features a compact design for wall mounting.

Image: Front view of the Optimus Instant Water Heater, Model OI-05 B. The unit is white with the Optimus logo at the top and a control knob at the bottom.

Image: Angled view of the Optimus Instant Water Heater, showing the side vents and the compact design. The unit is white with the Optimus logo at the top and a control knob at the bottom.
The unit's dimensions are approximately 30 cm (length) x 13.5 cm (width) x 48.8 cm (height), making it suitable for various indoor spaces.

Image: Diagram illustrating the dimensions of the Optimus Instant Water Heater. The height is 48.8 cm, length is 30 cm, and width is 13.5 cm.
Setup and Installation
The Optimus OI-05 B water heater is designed for indoor wall-mounted installation. Due to the nature of gas and water connections, professional installation is strongly recommended to ensure safety and proper functionality.
Installation Steps (Overview):
- Location Selection: Choose a well-ventilated indoor location, away from flammable materials, with easy access to water and gas lines. The unit is designed for wall mounting.
- Mounting: Securely mount the water heater to a sturdy wall using appropriate hardware. Ensure it is level.
- Water Connections: Connect the cold water inlet and hot water outlet pipes. Ensure all connections are tight and leak-free.
- Gas Connection: Connect the LP gas supply line to the water heater. Use appropriate gas-rated fittings and ensure a leak-free connection. Perform a leak test with soapy water.
- Ventilation: Ensure the exhaust vent is properly installed and unobstructed, directing combustion gases safely outdoors.
- Initial Startup: After all connections are secure and checked, slowly open the gas supply valve. Open a hot water faucet to allow water to flow through the unit and purge air from the system.

Image: The Optimus Instant Water Heater mounted on a brick wall, demonstrating a typical indoor installation. The unit is white and blends with the wall.
Refer to the detailed installation guide provided with the product packaging for specific diagrams and instructions.
Operating Instructions
The Optimus OI-05 B water heater features automatic ignition, simplifying its operation.
Basic Operation:
- Ensure Gas Supply: Verify that the LP gas supply valve is open.
- Water Flow: Open any hot water faucet in your home. The water heater will detect the flow and automatically ignite to heat the water.
- Temperature Adjustment: Use the control knob on the front of the unit to adjust the desired water temperature. Turning the knob towards the '+' symbol increases the temperature, and towards the '-' symbol decreases it.
- Shut-off: When the hot water faucet is closed, the water heater will automatically turn off.
The unit is designed to work effectively with both high and low water pressure, ensuring consistent performance.
Maintenance
Regular maintenance ensures the longevity and efficient operation of your Optimus Instant Water Heater. It is recommended to have the unit inspected by a qualified technician annually.
Routine Checks:
- Ventilation: Ensure the area around the water heater is clear and the exhaust vent is free from obstructions.
- Gas Connections: Periodically check gas connections for any signs of leaks (e.g., using a soapy water solution).
- Water Leaks: Inspect water pipes and connections for any drips or leaks.
- Cleaning: Keep the exterior of the unit clean. Do not use abrasive cleaners.
For any internal maintenance or repairs, always contact a certified service professional.
Troubleshooting
This section addresses common issues you might encounter with your water heater.
| Problem | Possible Cause | Solution |
|---|---|---|
| No hot water / Unit does not ignite |
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| Water not hot enough |
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| Unit leaks water |
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If troubleshooting steps do not resolve the issue, contact customer support or a certified technician.
Specifications
| Brand | Optimus |
| Model Number | OI-05 B Gas L.P. |
| Capacity | 5 Liters/minute (for 1 service) |
| Power Source | Liquid Propane (LP Gas) |
| Installation Style | Indoor Installation |
| Mounting Type | Wall Mount |
| Product Dimensions (L x W x H) | 30 cm x 13.5 cm x 48.8 cm |
| Item Weight | 5.58 kg |
| ASIN | B0B191GCX7 |
Warranty and Support
For warranty information, technical support, or service requests, please refer to the documentation included with your product or contact Optimus customer service directly. Keep your purchase receipt as proof of purchase for warranty claims.
Manufacturer: Optimus
For further assistance, visit the Optimus Brand Store.





