Ask us anything

How to replace A.O. Smith Master Fit ignitor?

Replacing the ignitor on an A.O. Smith Master Fit water heater is a relatively straightforward process that can be done with some basic tools and a bit of caution. Ignitors are critical components in gas water heaters, as they ignite the gas to heat the water. If you notice that your water heater isn't producing hot water and suspect a faulty ignitor, follow these steps to replace it:

1. Safety First: Always prioritize safety when working with gas appliances. Turn off the gas supply to the water heater and shut off the power at the circuit breaker or disconnect switch to ensure there is no risk of gas leaks or electrical accidents. Allow the water heater to cool down if it has been recently running.

2. Gather Your Tools: You'll need a few tools for this job, including a wrench, screwdriver, and a replacement ignitor compatible with your A.O. Smith Master Fit water heater model. Make sure to have the correct replacement part before starting the process.

3. Access the Ignitor: Open the access panel or cover on the front of the water heater. This panel is typically secured with screws. Use the screwdriver to remove the screws and carefully take off the cover to expose the internal components.

4. Locate the Ignitor: Once you have access to the inside of the water heater, locate the ignitor. It is usually a small, rectangular or square-shaped component positioned near the burner assembly. Take note of its orientation and connections for reference when installing the new ignitor.

5. Disconnect Wires: Carefully disconnect the wires or connectors attached to the old ignitor. These wires typically lead to a control module or circuit board. Note the color-coding or labeling of the wires, if present, to ensure proper reconnection later.

6. Remove the Old Ignitor: Use a wrench to carefully loosen and remove any mounting screws or brackets securing the old ignitor in place. Gently pull the ignitor out of its mounting position. Be cautious not to damage any surrounding components or wiring.

7. Install the New Ignitor: Take your replacement ignitor and position it in the same orientation and location as the old one. Secure it with the mounting screws or brackets, ensuring it is firmly in place but not overly tightened to avoid damage.

8. Reconnect Wires: Carefully reconnect the wires or connectors to the new ignitor, following the same color-coding or labeling as before. Ensure a secure connection to prevent electrical issues.

9. Replace the Access Panel: Put the access panel or cover back in place and reattach it using the screws you removed earlier. Make sure it is securely fastened.

10. Restore Gas and Power: Turn the gas supply back on and restore power to the water heater by flipping the circuit breaker or reconnecting the disconnect switch.

11. Test the Water Heater: Finally, test the water heater to ensure it ignites properly and produces hot water. Monitor it for a while to make sure there are no issues, such as unusual noises or gas odors.

If you encounter any difficulties during this process or are uncomfortable working with gas appliances, it's advisable to seek professional help from a licensed plumber or technician. Safety is paramount when dealing with gas equipment, so do not hesitate to contact a professional if you have any doubts or concerns about the replacement process.

In conclusion, replacing the ignitor on an A.O. Smith Master Fit water heater involves ensuring safety, gathering the necessary tools, accessing and disconnecting the old ignitor, installing the new one correctly, and conducting tests to verify its functionality. With careful attention to detail and safety precautions, you can successfully replace the ignitor and restore your water heater's operation.
Connect to virtual expert

Our virtual experts can diagnose your issue and resolve simple problems.