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A Simple Water Heater Blockage Can Lead to a Big Issue

Once your water heater intake gets blocked, your hot water supply can suffer. Don't let a lack of airflow create more problems — it's an issue that's easy to prevent and to fix.

Check Your Water Heater Intake

Gas water heaters need a constant flow of air in and out of the unit to create proper combustion. If the airflow is blocked in the inlet, your water heater won't be able to pull in enough air. Your burner may still light, but the flame won't be a healthy, hot blue.

If you see a yellow flame, your water heater is going to take much longer to heat up your water. If you have a tankless water heater, it will shut down completely and give you an error code.

How to check your water heater intake

  • 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 your water heater intake doesn't seem to be blocked and the issue persists, consider other reasons for no hot water.

What to Do if Your Water Heater Intake Is Blocked

Fortunately, you can usually fix a blocked water heater intake yourself by following the troubleshooting steps above. If that doesn't do the trick, you give a technician a call to get an expert eye on the problem.

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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