Marey heater vibrates excessively or rattles during operation.

Safety first: Turn OFF power and gas before tightening internal components.

Steps:

• Tighten mounting: Ensure the heater is firmly secured to the wall with appropriate anchors.
• Secure covers: Tighten all cover screws and internal brackets that may be rattling.
• Inspect fan (gas): Check the combustion fan for debris or bent blades and clean carefully.
• Address water hammer: Install or service water hammer arrestors if vibration coincides with valve closing.

When to call a technician: If vibration is severe or linked to fan or burner issues.