I have a 2 year old Sundance Caprio Spa. The heater stopped working after the cover had been left off all nite. Not sure if this was just a coincidence. The heater light is on at the control panel but the water never heats up. Visually, the heater and all controls look new. I used a volt meter to measure 240 volts coming out of the control panel to the heater. I get no readings on anything within the heater control box itself. Not sure what to do next. It's wired for 240v. Any help would be appreciated.

With the power disconnected from the tub, remove the two wires from the heater terminals in the heater box, and check the heater element by using a DVM (Volt/Ohm meter) set to read resistance. If your readings are infinite, then you need a new element. The heater should read below 100 ohms. The problem is coinsidence.

Just to check can you confirm which are the terminals in the attached picture of the heater box. Thanks...

try again w/ attachment

I checked the resistance at the terminals. It's reading 0. What do I need to look at next?