Spa Doctor--No Heat

If the heater light or icon doesn't come on the most common reason is the filter. To check is easy. Turn off main power and remove and leave filter(s) out for this test. Turn on power. If the spa heats (1-2 degrees per hour for 110vac spas; 4-5 degrees per hour 220vac) then you know either the filters need to be replaced or cleaned better.

If the heater light doesn't come on even with the filter(s) out, then it's likely 1 of 2 things. First and most common is the pressure switch. For interruption of heater because of the pressure switch, it's always best to replace. If not the pressure switch, it's the pcboard itself but this is rare.

If the heater light DOES come on it's either the heater itself or the pcboard. The only way to check is with a voltmeter. To perform this test you must have understanding of electricity and know how to use a volt/ohm meter.

Most likely the problem is a heater failure. Turn off main power. Set the meter for OHMS. Test the 2 posts of the heater. The diagram on the control box cover should help you identify the heater connections. On some spas its easier to test the wiring from the heater to the board. Post or wiring is fine. Make SURE the spa's power is OFF. You don't have to disconnect any wires to make this test.

The heater terminals-wire-posts should read 11-15 ohms resistance on most heaters. If not, replace the heater.

If the heater DOES have that resistance, Set the meter for above 250vac. The following test is down with power to the spa active. You MUST have experience in electrical tests to perform this test safely.

Again, set meter to VAC above 250.

While the spa is running and the heater light is ON you place the voltmeter probes on the 2 posts of the heater or whatever post you use to test OHMS. Be careful not to short anything with your probes. IF the meter shows nothing YET the heater light is on solid, you have a bad board. Replace the board..

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