5 Signs Your Pool Heater’s Heat Exchanger Is Failing

Rust-colored water around the burner Water leaking into the burner chamber from a cracked heat exchanger often appears as rust-colored water or puddles under the heater.

Soot around the burner Combustion gases leaking into the pool water leave soot deposits around the burner area and can cause a chemical smell at the water returns.

Frequent cycling or trouble holding temperature A failing heat exchanger may cause the heater to turn on and off more often or struggle to maintain set temperature, though this can also be due to a dirty filter or bad thermostat.

Steam or condensation in odd places Moisture where it shouldn’t be, like steam escaping from the heater or condensation inside the burner compartment, points to a cracked exchanger.

Heater is over 8–10 years old with these symptoms If your heater is old and shows rust or soot, replace the whole unit. Patching a cracked exchanger rarely lasts more than a season, and labor to swap it often costs more than a new heater.