State Vibration / Mounting or Fan Imbalance

State tankless water heater: unit makes loud vibrating or rattling noise when running.

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Loose mounting hardware, Imbalanced combustion fan, Loose vent piping, Scale causing turbulent flow

Safety: Turn off power and gas before tightening or adjusting components.

Check mounting: Ensure the heater is firmly secured to the wall with all mounting screws tight.
Inspect venting: Secure any loose vent sections and support long runs to prevent vibration.
Fan inspection: Check the combustion blower for debris on the wheel. Clean carefully.
Descale: Perform a descaling flush if water-side noise is suspected.

Medium 3/5

Combustion Blower Assembly

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