Your signature does not say what heater you have.
The
Pentair MasterTemp Heaters say:
- Operating this heater continuously at water temperatures below 68° F. (20° C) will cause harmful condensation and will damage the heater and void the warranty.
- When starting the heater for the swimming season with a water temperature below 50° F (10° C), the heater may be used to heat the water; however, make sure that the heater operates continuously until the water temperature reaches the heater’s minimum setting of 68° F (20° C).
The Hayward H-Series heaters say "Do not use the heater to maintain the water temperature just above freezing or for freeze protection."
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