Spa Heater High Limit Thermostat Tripped


Old 12-23-18, 06:12 AM
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Spa Heater High Limit Thermostat Tripped

Just replaced the heater and heater circuit board on my 2002 caldera utoptia spa. When I applied power, the water circulates, and the main circuit board LIM Green LED comes on just for a split second and then goes off, and HEAT LED red light does not come on. I get the Heater High Limit Thermostat Tripped error, and only the circulation pump is working, spa heater and jets do not come on.. Could this be a bad main board? I removed the filter, even though I had previously cleaned it, and it is not tripping due to heater getting too hot, since the heater is not even coming on.

I tested the temperature sensor for continuity and it was within tolerances, and the heater board is new. Changed out pressure sensor also. It will not come on now, except the water circulation pump is working.

Any ideas as to what else to trouble shoot? It was working, except not heating before I replaced the heater and other parts. Since the main board LIM LED comes on for half a second, something is causing it to not fully power on. How do I test if it is the main circuit board that is bad? I don't see any burns or bubbles or any physical sign the board is bad.

Last edited by jlcassio; 12-23-18 at 06:29 AM.
Old 12-23-18, 10:00 AM
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Welcome to the forums.

Typically there are two temperature sensors and a pressure switch controlling the heater operation. An LED lighting briefly on power up sounds like a normal occurrence.

What main control board does that spa use ?

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