Sorry, the web browser you're using is not supported by this website.

Please use Google Chrome, Firefox, Safari, or another browser to access Thank you.

Skip to main content

We use cookies to enhance your experience. For details on how we use cookies, collect data, & how to manage your consent please see our Cookie Policy & Privacy Policy.

Gas Line Can Cause Tankless Water Heater No Hot Water Problem

Tankless gas water heater pressure needs to be perfect for hot water to flow properly. A licensed plumber or a gas fitter can check the gas line to see if a pressure issue is causing no hot water.

Check Your Tankless Water Heater Gas Line

Your tankless water heater’s gas line uses gas to heat your water. If you don’t have the right size gas line with the appropriate gas pressure, your unit won’t be able to produce hot water.

How to check your tankless water heater gas pressure

  • 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.

  • If your system is showing a "Water Heater Not Igniting" or "Returning Flame Failure Message", it means that the pilot light won't light. This could be due to low gas pressure, but there are a number of other reasons that could also interfere with the pilot light. You'll need to call a technician to determine why it won't stay lit.

  • If you suspect that the gas pressure is too low, a technician will have to come out with an instrument called a manometer to measure the gas pressure.

Is there a problem with your tankless water heater’s gas line? If not, consider other reasonsfor why your water heater can't handle the heat.

What to Do if Your Tankless Water Heater Gas Line Pressure Is Low

When your tankless water heater is acting up due to gas pressure problems, it’s best to have a licensed plumber inspect it.

Need a hand? Connect with one of our Remote Assist technicians who can diagnose your tankless water heater issues over the phone or video call––helping you get your hot water 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.

Let's Get It Fixed!

HomeX virtual experts will assess your issue (for free!) and can resolve simple problems.

What Did You Think of This Article?

What Did You Think of This Article?