Rheem Furnace Flame Sensor Parts — Models & Compatibility

Your Rheem furnace fires up for a few seconds, then shuts right back down. That's the classic sign of a failing flame sensor — and this 62-23543-01 sensor fits over 20 Rheem, Ruud, and WeatherKing furnace series. It replaces the original 62-23543-02, 62-23543-03, and 62-23543-04 part numbers that Rheem discontinued years ago.

This hub covers which models use this exact sensor and how to verify you've got the right part before you order.

Is This the Right Part for Your Model?

Check your furnace's model number plate — it's usually mounted inside the front access panel or on the right side of the blower compartment. You're looking for a model number that starts with letters like RGDG, RGLG, RGPH, or RGRA. If your model number matches any in the compatibility list below, this sensor will work.

The 62-23543-01 crosses over with four different Rheem part numbers. If your old sensor shows 62-23543-02, 62-23543-03, or 62-23543-04 stamped on it, this is the current replacement.

About This Replacement Flame Sensor

The flame sensor is a thin metal rod that sits in the burner flame path. It detects whether the gas burners are actually lit — if it doesn't sense flame within a few seconds, the furnace shuts down to prevent raw gas from pumping into your home. Pretty important safety device.

Over time, these sensors get coated with carbon buildup and oxidation. Even a thin layer will prevent proper flame detection. You'll notice your furnace starting to short-cycle — lights for 5-10 seconds, clicks off, tries again in a minute. That cycle repeats until either the sensor clears (rare) or the system locks out completely.

Most techs try cleaning the sensor first with fine steel wool or a dollar bill (seriously, that works). But if your sensor's been in service for 8-10 years or the rod looks pitted and corroded, replacement is the better call. This part costs $15.99 — a service call to have someone else diagnose the same issue runs $150-200.

Compatible Rheem Furnace Series

This flame sensor works across multiple Rheem product lines — their standard efficiency upflow models, horizontal installations, and even some WeatherKing branded units that Rheem manufactures. The part's been consistent across their mid-efficiency furnace lineup since the early 2000s.

If you've got a Ruud furnace, check the model number anyway. Ruud is Rheem's sister brand, and they share tons of parts between the two lines. Same sensor, different nameplate.