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Don't Let A Water Heater Exhaust Blockage Exhaust You

When your water heater exhaust is blocked, your unit will shut off to prevent gases from entering your home. At this point, you'll want to check the exhaust to safely get hot water back in your pipes.

Check Your Water Heater Exhaust

Inside your water heater's combustion chamber, the burning fuel produces gas. Those gases are then moved out the exhaust pipe so they don't enter your home. In the event your exhaust or vent pipe gets blocked, the unit will shut down to prevent any further damage.

How to check your water heater exhaust

  • Check for an error message on the display of the water heater and write down the error code. Check your owner's manual or the system's website and look for the section on error codes. It should tell you what each error code means.

  • Carefully (it can be hot) try moving the PVC intake and exhaust pipes gently. If either pipe are loose, it's not secured correctly.

  • Depending on the unit you have, you may have a dedicated air inlet and exhaust pipe or a combination intake and exhaust. Whichever you have, follow the pipes from your tankless water heater and you'll be able to locate the pipes on the outside of your home. Look around the pipe and make sure there are no leaves, plants, or other debris blocking the pipe. If you don't see anything blocking it on the outside, look inside the pipe with a flashlight. Be careful when looking inside, sometimes bees like to make a cozy nest inside the warm piping.

  • Winter can create specific challenges. The building code requires the air intake and exhaust to be placed high enough off the ground to avoid snow blocking the pipe. However, if you get an unusual amount of snow, it could still happen. Ice can also be a concern. Water vapor in the exhaust will condense and drip from the exhaust pipe. If that condensation freezes, it can start to block the exhaust.

If the water heater exhaust doesn't seem to be the issue, consider what else might be causing no hot water.

NOTE: This content is for informational purposes only, and HomeX and its affiliates disclaim all liability related to it. If you decide to perform any tasks based on this information, you assume all risks, including the risk of loss or damage to property or personal injury.

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