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Step Four: Heaters

Heaters have a "normal" life about 5 years but they can last many more years. Manufacturers of heaters believe the longevity of a heater is totally related to the water quality of the spa. Hard water, too little chemicals, too much chemicals, not enough water flowing pass the element... all contribute to early heater failure. I have seen the same heater last less than 12 months and 12 years. So keep your water ph balanced and use the least amount of chemicals to keep your water perfect.

To test a heater is fairly easy. First, turn off main power to the hot tub. Set your voltmeter to OHMs. With OHMS you test the resistance of the heater. Heater element resist electrical flow and in doing so emits heat. So expect to see 10-15 ohms resistance on you meter. If not it indicates the heater has failed.

Then turn on power to the hot tub. CHANGE the meter to 300vac or higher. When the heater light on your topside is on solid, CAREFULLY place a probe from the meter on each heater post. Since the hot tub is saying its applying either 115v or 230v (heater light is on) you should see voltage. If you DO and its not heating, its a failed heater. If you do NOT see the correct voltage, then you have a failed board. The solid heater light shows the board "thinks" its applying correct voltage and it's not. Replace PCboard.

As a rule of thumb, spas operating on 115v will heat 1-2 degrees per hour. Spas operating on 230v will heat 5-6 degrees per hour.