Good morning!
Thank you in advance for your help.
I have a Marquis 2000 sport spa.
My digital control is set at 101 degrees. I have noticed that the heater light on the display is on constantly along with the circulation pump. The tempature has been staying at about 92 to 97 degrees over the past two weeks with night tempatures dropping below freezing. The heater must be working at some level. I have also noticed that while the heat light is on with the circulation pump running that the house electrical meter is not spinning at a fast rate as is the case when the spa heater normaly kicks on. So it seems not to be drawing full 220 voltage.

Thank you for your help!

Yours truly,

Bryan Sherwood
Colorado Springs, Colorado

sounds to me like your spa is maintaining a residual heat from the pumps. The heater itself appears to be inoperative. Check for voltage across both heater terminals. If you have sufficent voltage, your element is probably open. To confirm, do a resistance check across the terminals (power disconnected, wires removed) and see if you get infinite or high resistance. Should be around 11 Ohms.