John Moore Posted December 26, 2021 Report Share Posted December 26, 2021 Can anybody tell me what the constant red LED on my control board means? The LED is located next to the marking D21 and below marking F51. The other LED's that are lit are Limit OK which is constant green and PWR ON which is flashing green. On the outside of the tub the Hotsprings Logo lights are both flashing too. I have checked the and fitted the following; 1. New filter. 2. New High Limit Sensor. 3. Checked circ pump for air lock - all clear. 4. Tried new circ pump but to no avail. I want to confirm these LED's before I start investigating possible blockage. Cheers Quote Link to comment Share on other sites More sharing options...
imlost Posted December 26, 2021 Report Share Posted December 26, 2021 From my research, I've not been able to find info on what the D21 LED is for. It seems that steady red is normal function, though. My money is on the pressure switch (or flow switch) needing replacing. Quote Link to comment Share on other sites More sharing options...
John Moore Posted December 27, 2021 Author Report Share Posted December 27, 2021 Many thanks for your reply. I shall investigate that further. Quote Link to comment Share on other sites More sharing options...
RDspaguy Posted December 27, 2021 Report Share Posted December 27, 2021 Post pics of circuit board. Many IQ2020 systems do not use a pressure/flow switch. The flow switch connection on the board may just have a jumper on it. If not, you can jumper that for testing. If it works while jumpered it is an open switch, which can be a bad switch, a chewed wire or loose connection, or a flow issue. I recommend replacing both thermistors at once. You can test them with an ohm meter in the 20k ohm range. Quote Link to comment Share on other sites More sharing options...
John Moore Posted January 6, 2022 Author Report Share Posted January 6, 2022 Many thanks. I will put a jumper across the flow switch connectors to see if it is the flow switch that's open. When you say thermistors, do you mean the Control Sensor and High Limit Sensor as I replaced both of these as the High Limit Sensor was defective? Quote Link to comment Share on other sites More sharing options...
RDspaguy Posted January 6, 2022 Report Share Posted January 6, 2022 Yes, thermistors are sensors. Quote Link to comment Share on other sites More sharing options...
pdelahaye Posted January 7, 2022 Report Share Posted January 7, 2022 I've no idea how much these IQ2020 PCB's have changed over the years, but on my 2009, when the red LED is lit, it's indicating the board is calling for the Heater to be on. It required the pressure switch to either be working or bypassed to make the red light come on. There are some pictures here of my IQ2020 PCB for comparison. I don't have a Power LED, only the limit one, so it sounds like it might have changed a bit. Quote Link to comment Share on other sites More sharing options...
RDspaguy Posted January 8, 2022 Report Share Posted January 8, 2022 The power led is on the control panel, not the board. They have not changed much visually, but some systems are obsolete and not compatible with new replacement relay boards, which have visually changed several times. Quote Link to comment Share on other sites More sharing options...
Elad Posted September 29, 2022 Report Share Posted September 29, 2022 I have a similar issue with red light by D21 and flashing green power on indicator light on my IQ 2020. The 30 switch on my breaker usually trips randomly in the middle of the night every 1-2 days as well. any idea what might be going on? Photo here Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.