Gas leak check before startup

What is going on

First thing I do on any gas appliance startup is use my nose. Before and during the first start, smell at the floor and around the boiler. If there is any sign of a gas leak, do not start it. Propane is the one that fools people, because the odorant can fade in a tank or new piping and you may smell nothing even with gas present. That is why the supplier should verify the odorant level, not you guessing.

Likely causes

• Gas leak at fittings, unions or valves from install or handling
• Propane odorant level too low, so a leak goes unnoticed
• Loose connection disturbed during boiler setup
• Damaged flex connector or gas valve seal

Check in this order

1. Smell near the floor and around the boiler before startup, since propane sinks.
2. Remove the front door and smell inside the enclosure.
3. If a leak is suspected, shut the boiler down at once, leave the area and do not operate switches or flames.
4. Find the leak with a bubble test and repair it before restarting.
5. Only licensed gas technicians should repair gas connections.
6. For propane, have the supplier confirm the odorant level before startup and periodically after.
7. Recheck every joint with leak solution after the repair, then start again and recheck at full fire.

More boiler guides

• Access the low voltage wiring connections
• Blocking errors versus lockout errors
• Blower not running
• Blower runs at high speed with burner off
• Boiler bangs or hisses; Lockout 81 delta T
• Burner not running on a call for heat