Installing a gas combi boiler involves several key steps and requires technical expertise. This comprehensive guide will walk you through the process, providing detailed instructions and technical specifications to help you successfully install a gas combi boiler in your home or business.
Mounting the Boiler
- Prepare the Mounting Surface: Start by mounting a plywood panel to the basement wall. This will serve as the mounting panel for your new combination boiler.
- Attach the Mounting Brackets: Securely screw the metal mounting brackets to the plywood panel, ensuring they are level and properly spaced to support the weight of the combination boiler.
- Hang the Boiler: Carefully lift the combination boiler and hang it onto the mounted brackets, making sure it is level and securely in place.
Running New Lines
- Gas Line: Run a new gas line from the main supply to the plywood panel, ensuring it meets local building codes and safety regulations.
- Electrical Line: Install a new electrical cable from the main power source to the combination boiler, providing the necessary power for its operation.
- Plumbing Lines: Connect hot and cold water lines from the plumbing system to the combination boiler, ensuring proper water supply for both the heating system and domestic water fixtures.
Venting
- Exhaust Vent: Drill a 4-inch-diameter hole through the exterior wall for the exhaust vent. The vent should be positioned at least 12 inches from any windows and 12 inches from the air intake vent.
- Air Intake Vent: Drill a second 4-inch-diameter hole through the exterior wall for the air intake vent. Ensure the air intake is positioned above the snow line to prevent blockage.
- Vent Piping: Use PVC pipe and fittings to create the exhaust and air intake vents, running the piping from the boiler through the exterior wall.
Connecting Water Lines
- Heating Supply: Connect the heating supply line from the combination boiler to the heating system, ensuring proper water flow and circulation.
- Domestic Hot Water: Connect the domestic hot water line from the combination boiler to the plumbing system, providing hot water for household use.
- Domestic Cold Water: Connect the domestic cold water line from the plumbing system to the combination boiler, ensuring a reliable water supply.
Connecting Gas and Electrical Lines
- Gas Line Connection: Securely connect the new gas line to the combination boiler, following local building codes and safety regulations.
- Electrical Connection: Connect the new electrical cable to the combination boiler, providing the necessary power for its operation.
Installing Temperature Sensor
- Outdoor Temperature Sensor: Mount an outdoor temperature sensor on the north side of the house, as this will help the combination boiler regulate the production of hot water based on the outdoor temperature.
Condensate Line
- Condensate Drainage: Run a PVC condensate line with a limestone neutralizer from the combination boiler to a nearby utility sink drain or floor drain. Use a condensate pump if necessary to effectively drain the excess condensation.
Final Check and Startup
- Boiler Startup: Turn on the combination boiler, and it should immediately start producing hot water for your heating system and domestic use.
- Old Equipment Removal: Once the new combination boiler is fully operational, remove and discard the old boiler and water heater.
Technical Specifications
Navien Combi-Boiler Installation Diagram
The Navien NCB-H combi-boiler features the following supply connections (with dimensions) on the top and bottom of the unit:
– Pressure relief valve adapter
– Air intake (4-inch diameter)
– Exhaust gas vent (4-inch diameter)
– Heating supply (1-inch diameter)
– Domestic hot water (3/4-inch diameter)
– Gas connection (3/4-inch diameter)
– Domestic cold water (3/4-inch diameter)
– Auto feeder inlet (1/2-inch diameter)
– Condensate outlet (1/2-inch diameter)
– Heating return (1-inch diameter)
Wiring Diagrams
Navien provides multiple installation diagrams for various applications, including:
– Zone systems with pumps
– Zone systems with zone valves
– Air handler systems
– Cascade system applications
Gas Supply Piping Diagrams
The installation manual includes diagrams for both natural gas (NG) and liquefied petroleum gas (LP) piping configurations.
Venting Diagrams
The manual provides diagrams for direct venting, non-direct venting, and common venting configurations.
DIY Considerations
Safety
For safety reasons, it’s highly recommended to have a professional heating contractor assist with the installation of your new combination boiler. The process involves running new gas, electrical, and plumbing lines, as well as drilling holes through the house wall for the vents, which requires precision and technical expertise.
Cost
The cost of installing a combi-boiler in your home or business can vary depending on several factors, such as the availability of suitable venting pipes, the amount of gas and water piping that needs to be installed, and the overall complexity of the job.
Estimated Time
The installation process typically takes 6 to 8 hours, depending on the complexity of the job and the specific requirements of your home or business.
References
- This Old House. (2015). How to Install a Combination Boiler/Water Heater. Retrieved from https://www.youtube.com/watch?v=BuxvKbIIYLU
- CombiBoiler. (2017). How to Install a Combination Boiler Baxi Gas Combi Boiler Installation. Retrieved from https://www.youtube.com/watch?v=5GHT834JUOY
- LovingPlumbing. (2022). How to install a Combi boiler conversion – Worcester 8000. Retrieved from https://www.youtube.com/watch?v=vVjYDO8P-FU
- Navien. (2023). Combi-Boiler Installation. Retrieved from https://www.navieninc.com/blog/notice/combi-boiler-installation
- This Old House. (2015). How to Install a Combination Boiler and Hot Water Heater. Retrieved from https://www.thisoldhouse.com/plumbing/21016999/how-to-install-a-combination-boiler-water-heater