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How To Test A HotSprings IQ 2020 Heater Relay Board

LIM OK HTR ON 800-

How To Test Your IQ 2020 Heater Relay Board

In this post, we are going to teach you how to test and troubleshoot the heater relay board in your Hotspring Spa’s IQ2020 control box. If your spa is not heating, there is a good chance there could be an issue with the heater relay board. There are just a handful of simple steps needed to figure out the source of the issue. Follow the steps laid out in this post and you will have your answer in no time!

Heater Relay Board Pre-test checklist:

• Determine which heater relay board generation you have (1st, 2nd, 3rd, or 4th Generation) and find the directions that belong to that version.
• The red “Power” light on the control panel must be on solid and NOT blinking. If it is blinking, contact our helpdesk.
• The green “Ready” light on the control panel should be off.
• The temperature on the control panel must be set higher than what the temperature of the spa water is.
• Have your voltage meter (aka Multi Meter)
• Phillips Screwdriver and needle-nose pliers handy (for testing 1st & 2nd Generation).

Testing 3rd and 4th Generation IQ 2020 Heater Relay Board

IQ2020 Control box

Step 1
Turn the temperature to the highest setting on the control panel. The temperature on the control panel must be higher than the temperature of the spa water. The green ready light on the control panel should be off.

Step 2
Remove the screws from your equipment compartment door and set the door aside. Then, remove the two small Phillips screws that hold on the front cover of the IQ 2020 Control Box and set the cover aside.

LIM OK HTR ON 800-

Step 3
Look at the circuit board (motherboard) on the right and make sure that the two LED lights are lit. The green LIM Ok light and the red HTR ON light. It is important that the red HTR ON light is lit before continuing.
If it’s not, then there is a problem with your motherboard and you will need to troubleshoot with one of our technicians. Please contact us via our helpdesk or call us at (805) 541-9000 or text at (818) 583-0350.

d9 and d10 lights 1400x1000 1-

Step 4
On the heater relay board, look for the two LED lights D9 (Red) and D10 (Green) on the top. They should both be lit. If D9 is flashing, that is an indication that the heater relay board is bad or needs to be reset with a new motherboard.
*The 3rd Generation (Invensys) heater relay board does not have a D9 or D10 light. If you are testing at 3rd Generation board, please skip to the next step.

Voltage Meter-

Step 5
Using your multimeter, set the voltage meter higher than 300 ACV. Meters vary in design so you will need to be familiar with yours. Make sure there is a fresh battery in the meter.

77119 heater board test 5 H1 and H2 115 120 volts zoomed in-

Step 6
Put one probe from your voltage meter onto the H1 terminal and the other probe onto the H2 terminal. It will not matter which probe goes onto the H1 and H2.

77119 heater board test 5 H1 and H2 115 120 volts-

Step 7
Check the reading on your meter. In this test, the spa is wired for 115 volt and the reading is good.

CONCLUSION

If your voltage reading was lower than 100 volts, then the board is damaged and has to be replaced. It is not repairable. Sometimes you can see visible smoke residue between one or more of the black relays (relays are shown above the probes on the Step 6 picture). The 77119 Heater Relay Board is the newest upgraded beefier heater relay board. The original 73355 & 74618 circuit boards were discontinued.

My voltage reading was zero
If you know for sure that you are making a solid connection between the voltage meter probes and the heater board terminals, a voltage reading of zero indicates that the board has failed and needs to be replaced. You can buy a new heater relay board now or Contact us with any questions you may have.

My spa is wired 240 volts and my voltage reading was between 215 volts-250 volts.
Your heater relay board is okay but your heater may not be. Contact us so we can walk you through the next steps.

Testing 1st & 2nd Generation IQ 2020 Heater Relay Board (Invensys)

IQ2020 Control box

Step 1
Remove the screws from your equipment compartment door and set the door aside.

Step 2
Remove the two small Phillips screws that hold on the front cover of the IQ 2020 Control Box and set the cover aside.

LIM OK HTR ON 800-

Step 3
Look at the circuit board (motherboard) on the right and make sure that the two LED lights are lit. The green LIM Ok light and the red HTR ON light. It is important that the red HTR ON light is lit before continuing. If it’s not then please contact us.

locating heaters power leads 300-

Step 4
Now turn off the power to your spa. Either unplug it if it’s 120-volt model or turn off the breakers if it’s wired 240 volts.

Step 5
Find where the black and white wire from the heater’s power cord connects onto the front of the heater relay board. The black wire should be connected to the P3 terminal and the white wire onto the P2 terminal.

disconnecting heater from board 300-

Step 6
With the power OFF to the spa, gently remove the black wire from the P3 terminal and the white wire from the P2 terminal. If the power is still on to the spa, the board will short out when you remove these wires.

setting voltage meter for 230volt spa 300-

Step 7
Turn the power back on to the spa.

Step 8
Set the voltage meter higher than 300 ACV . Meters vary in design so you’ll need to be familiar with yours. Make sure there is a fresh battery in the meter.

voltage meter probes on P2 and P3 flag terminals 300-

Step 9
Put one probe from your voltage meter onto the P2 terminal and the other probe onto the P3. It won’t matter which probe goes onto the P2 & P3.

CONCLUSION

If your voltage reading was lower than 100 volts, then the board is damaged and has to be replaced. It is not repairable. 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). The 77119 Heater Relay Board is the newest upgraded beefier heater relay board. The original 73355 & 74618 circuit boards were discontinued.

My voltage reading was zero
If you know for sure that you are making a solid connection between the voltage meter probes and the heater board terminals, a voltage reading of zero indicates that the board has failed and needs to be replaced. You can buy a new heater relay board now or Contact us with any questions you may have.

My spa plugs into a 120-volt outlet and the voltage reading was between 110 volts-130 volts.
Your heater relay board is okay but your heater may not be. Contact us so we can walk you through the next steps.

My spa is wired 240 volts and my voltage reading was between 215 volts-250 volts.
Your heater relay board is okay but your heater may not be. Contact us so we can walk you through the next steps.


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Thank you for reading this testing guide from Backyard Plus! If you have any questions about your HotSpring Spa, please don’t hesitate to give us a call! 1-805-541-9000.

6 thoughts on “How To Test A HotSprings IQ 2020 Heater Relay Board

  1. Hello. So I have a hot spring vista with 240 volts, and the multimeter is reading 120 volts when I check it across the white and black terminals on the heater board. You don’t have a answer to that scenario do ya? Thanks

  2. Hi Jason-
    Verify you have 220V between TB1 & TB3 on the Terminal Block. Then measure between the White & Black wires of the Heater Power Cord. If you only have 120V, the Relay Board needs to be replaced. If you have any other questions or want to troubleshoot further, please reach out via phone 805-541-9000, text 818-583-0350 or by help desk and our technicians will be happy to help you.
    Thanks!

  3. So when I checked my board my D10 green light wasn’t on when I got to step 4. Your walkthrough just says it should be on, but nothing about if it is off. Is that an indication the board has failed or something else?

  4. Hi there, Holland-
    If the Green “D10” is not lit, the Heater Relay Board is not detecting the Incoming Voltage between Terminals TB-1 & TB3 on the Terminal Block. Check Voltage between TB1 & TB3, it should be 220V for the 220V spas. If no voltage present, Check the Sub-Panel for a tripped GFCI Breaker. Reset the Breakers. Still no Green “D10”, service required. Please contact our technical department and they can help you troubleshoot further. They can be reached via phone 805-541-9000, text 818-583-0350, or through our helpdesk.
    Thanks!
    Rebekah

  5. Tub will not turn on. Power to gfci verified, power to heater board model verified, power to main control module verified. Has a gen 4 heater module. Appears to be latest control board module. Removed and reinstalled remote battery. Reset breakers with approx. 15 minutes between off and on.

  6. Hi, Ricky-
    It sounds like you may be having issues with your wireless control panel (remote). I will open a help ticket for you and have one of my technicians reach out.

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