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Is a Blocked Exhaust Causing a Gas Hot Water Heater Venting Problem?

A blocked water heater exhaust may have shut off your water heater to prevent gases from entering your home. This venting issue is actually protecting you, but you won't have hot water.

Check Your Water Heater Exhaust

When your water heater exhaust is blocked, your home won’t be able to deliver hot water through your taps. To get your system back on track, check on your water heater exhaust pipe.

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.

Is your water heater exhaust blocked? If not, consider other reasons for why you have no hot water.

What To Do If Your Water Heater Exhaust Is Blocked?

When your water heater exhaust is blocked, it’s best to have a certified plumber inspect it.

Reach out to one of our Remote Assist experts, who can guide you through the issue and help get your water heater back on track!

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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