Why is My Tankless Water Heater Makes Loud Noises? ^Featured

Tankless water heaters will all make some noise when starting up and heating water, but the noise levels are usually reasonable and not cause for concern. When the noise occurs when there is no hot water being used, it’s likely there is a vacuum that’s siphoning water away from the unit and causing loud noise and vibration. In most cases the solution is to have a plumber install a check valve in the water line to prevent other plumbing fixtures from interfering with the flow of water to the water heater.

Another common problem that can create noise in tankless water heaters is a dirty flow sensor which controls how much gas is sent to the unit. Other sources of noise include blocked or inadequate ventilation or a defective or improperly set pressure valve.

Because there can be many causes of the noise, it’s best to have your plumber diagnose the problem and fix the unit if needed.