I have a calspa with a whisper 5000 it will not heat up past 89 is there two stages of the heater and one is out I have 124 volts to each lug to the heater any advice would be great thanks

1. Grammar, punctuation and reasonable use of the English language. If no one can understand you, and you're not willing to spend the time to properly ask a question, do you think we're going to spend the time trying to help?

3. Heaters are like light bulbs... they're either on or off. No in between (stages)

2. The only way to PROPERLY test for 240v is to test from heater lug to heater lug.