My spa plugs into a 120 volt outlet and the voltage reading was between 110 volts-130 volts. The original 73355 circuit board was discontinued in 2008.ДЄ voltage reading of zero indicates a few other possibilities.Д¬ontact us so we can walk you through the next steps. The 74618 Heater Relay Board is the newest upgraded beefier heater relay board. Sometimes you can see visible smoke residual between one or more of the black relays (relays are shown above the probes on the Step 9 picture). If your voltage reading was lower than 100 volts, then the board is damaged and has to be replaced. My voltage reading was less than 100 volts It won't matter which probe goes onto the P2 & P3. Put one probe from your voltage meter onto the P2 terminal and the other probe onto the P3. Make sure there is a fresh battery in the meter. Meters vary in design so you'll need to be familiar with yours. Set the voltage meter higher than 300 ACV. If the power is still on to the spa, the board will short out when you remove these wires. With the power OFF to the spa, gently remove the black wire from the P3 terminal and the white wire from the P2 terminal. The black wire should be connected onto the P3 terminal and the white wire onto the P2 terminal. Either unplug it if it's 120 volt model or turn off the breakers if it's wired 240 volts.ДЇind where the black and white wire from the heater's power cord connect onto the front of the heater relay board.

It is important that the red HTR ON light is lit before continuing. The green LIM Ok light and the red HTR ON light. Look at the circuit board (motherboard) on the right and make sure that the two LED lights are lit. Remove the two small Phillips screws that hold on the front cover of the IQ 2020 Control Box and set the cover aside. Remove the screws from your equipment compartment door and set the door aside. Have your voltage meter (aka Multi Meter), and a Phillips Screwdriver and needle nose pliers handy.The temperature on the control panel must be set higher than what the temperature of the spa water is.The green 'Ready' light on the control panel should be off.The red 'Power' light on the control panel must be on solid and NOT blinking.Testing electrical components can be dangerous and even deadly. Warning: If you're not familiar with electricity, then call an electrician or qualified Hot Spring service tech.

Hot spring iq 2020 manual