Combustion air and leak protection checks during install

What is going on

These are the basic site checks to make before the boiler is set in place. It's the walk-around that catches problems while they're cheap to fix, like a missing drain, water piping in the wrong spot or a pile of paint cans next to the burner. It applies on a new install and especially on a replacement, where the old system may bring leaks and an undersized tank along with it.

Likely causes

• New boiler install where utilities and clearances need confirming
• Replacement where old leaks, freeze risks or an undersized expansion tank were ignored
• Mechanical room used for storage of combustibles
• Location where a leak could cause serious water damage

Check in this order

1. Check for nearby system water piping, vent connections, gas supply, power, and condensate drain.
2. Remove combustibles, gasoline and flammable liquids from the area.
3. Protect gas controls from dripping water during operation and service.
4. On a replacement, correct system leaks, freeze risks, and an undersized expansion tank.
5. Flush the system when reinstalling a boiler.
6. Install leak containment (drain pan or pitched floor) and consider leak detection with an automatic shutoff if damage is possible.
7. Have a licensed tech do the gas and venting connections.

More general guides

• Expansion tank and air elimination
• Install and test the CH and DHW relief valves
• Low water cut-off wiring (field supplied)
• Primary/secondary piping and 3-way valve for heating-only use
• Removing the boiler from a common vent system
• Wall mounting the boiler