My 220 volt spa no longer gets hot

Yes, it is

Measure the voltage across both hot wires coming from the house. You should see 220 volts on your volt meter - note that measuring from each wire to the ground will not give an accurate reading). 

No, it is not

If you are not getting any error messages in the display screen (blinking dots is an error message) then please proceed, otherwise find the steps below to troubleshoot error messages. 

In order for the spa to heat, the heat indicator light needs to be on the topside control. If it is not then there may be an issue with the pressure switch (it may be defective). 

The pressure switch screws into the heater manifold and has cable leading from the circuit board with two small wires that attach to it; one on each terminal. 

Use the instructions provided below to bypass the pressure switch to see if it is the cause of the "no heat". Note that not all spas have a pressure switch, so these instructions may not apply. 

1- Power the circuit board down, then unplug the pressure switch cable from the circuit board revealing two pins. 

2 - Power up the system. As soon as the low/filter pump turns on, jump the two pressure switch pins on the board with alligator clips. Don't worry, you will not get shocked as the pins are low voltage. 

Did the heater light come on on the topside control? If so, the pressure switch or the pressure switch cable is defective and should be replaced. If the light did not come on, then the circuit board will need to be replaced.