Yes, a gas or oil-fired water heater can cause carbon monoxide problems if it is not venting properly or its burner is not working right. Carbon monoxide, or CO, is a colorless, odorless gas that can make people very sick, which is why venting and working CO alarms matter.
Why It Can Happen
Fuel-burning water heaters create exhaust gases, including carbon monoxide. A vent pipe carries those gases outside. If the vent is blocked, disconnected, rusted through, or not drawing air properly, exhaust can spill into the home. A burner that is dirty or not getting enough air can also produce more CO than normal.
Symptoms and Clues
- A CO alarm sounding
- Headaches, dizziness, nausea, or tiredness that improve when you leave the house
- Soot or scorch marks around the top or bottom of the heater
- A yellow or flickering burner flame instead of a steady blue one
- A vent pipe that is loose, rusted, or sagging
If an Alarm Sounds
If a CO alarm sounds or people feel sick, get everyone outside to fresh air right away and call 911. Do not go back inside until emergency responders say it is safe. Do not try to inspect or repair the heater yourself. Your gas utility may also be able to check the appliance once the home is safe.
Prevention
Install CO alarms on every level of the home and near sleeping areas. Test them monthly and replace batteries as needed. Have fuel-burning appliances, including the water heater, checked once a year. Keep the area around the heater clear so it gets enough air, and never store paint, gasoline, or cleaning chemicals near it. Electric water heaters do not produce carbon monoxide.
If you see soot or a damaged vent, having the heater and venting inspected is an important safety step. For general questions about gas appliances and plumbing, you can ask about safe setups for gas appliances at (833) 603-1840.