Aqualink RS8 erratic pump relay cycling during freeze protection

CJH_KLAS

Member
Jan 10, 2021
6
Henderson, NV
Aqualink RS8 erratic pump relay cycling during freeze protection

When freeze protection is active, the main pump erratically cycles on and off. This only occurs when freeze protection is active. I have adjusted multiple times the temperature set point for freezing, but regardless of the set point, when freeze protection is active the pump cycles on and off erratically. I have an Aqualink RS8 controller, and since I have purchased the home 2 years ago, this has been occurring anytime freeze protection is active. A previous post identified a solution: “cycle the main power to the system, then clear the memory, and reprogram devices, time and temperature settings. FINALLY, assign an unused device to freeze protection.”

This has not resolved my erratic pump relay cycling during freeze protection.

Any ideas?
 

1poolman1

In The Industry
Jul 14, 2014
73
Sacramento
Not sure what qualifies as erratic operation. Have you changed the Jandy "air temperature" sensor. With the pump running, your display should show air temperature. Is it correct? It will be the sensor that should be hanging outside the control panel or mounted externally. I have seen them left inside the panel and this will give erroneous results.
 

CJH_KLAS

Member
Jan 10, 2021
6
Henderson, NV
Hello 1poolman1...
I changed the temp sensor outside - no change. Yes, the panel accurately reads outside air temperature. By erratic, I mean inconsistent, irregular, non-uniform. I.e. On for 1 second, off for 2 seconds, on for 3 seconds, off for .5 second, on for .5 second, off for 2 seconds, on for 3 seconds, off for 1 second, etc. etc. etc...
Anyone else?
 

superuser

Well-known member
Nov 16, 2020
72
Spring, TX
The timing was the key piece of info everyone was looking for. On/off every few hours vs. sub-second makes a huge difference.

I'm not fully versed on the RS even though I have one too, but it sounds like you have conflicting commands being sent. You might try disconnecting everything from the RS485 bus in the panel and see if it calms down. If it does, you might have a PDA or other remote control flooding the bus with 'pump off' messages, while the panel is turning the pump back on for freeze protect.
 

CJH_KLAS

Member
Jan 10, 2021
6
Henderson, NV
Hello superuser, thanks for the ideas. I already removed power from the system and did a complete reset. No change. There are no PDAs for this system.
Of note, when I simulate cold weather by submerging the temperature sensor into a cup of ice, the freeze protection activates and functions properly without erratic cycling. I tried this with both the old sensor and the new, same result.
This erratic pump cycling only occurs when the actual atmospheric conditions match the temperature that I have set for the freeze protection.
Anyone else..?
 

PoolGate

Gold Supporter
TFP Guide
Jun 7, 2017
5,536
Damascus, MD
Pool Size
29000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Jandy Aquapure 1400
Hello superuser, thanks for the ideas. I already removed power from the system and did a complete reset. No change. There are no PDAs for this system.
Of note, when I simulate cold weather by submerging the temperature sensor into a cup of ice, the freeze protection activates and functions properly without erratic cycling. I tried this with both the old sensor and the new, same result.
This erratic pump cycling only occurs when the actual atmospheric conditions match the temperature that I have set for the freeze protection.
Anyone else..?

Freeze protection uses the air-temperature gauge to activate, not the water temperature gauge. Make sure each of these is properly plugged in and in the proper location. Where is your air-temp gauge? Is it someplace that might get warm when the system is running like near the pump itself?
 

1poolman1

In The Industry
Jul 14, 2014
73
Sacramento
If you have a "spa-side" button, open the panel and unplug the connector with 6 wires. You can leave it in the panel pushed out of the way. They are notorious for causing erratic operation at most anytime. Whenever I call tech support for an Aqualink the first question to me is usually, "Is there a spa button in the system?" Then, "Try disconnecting it and see what happens." Give it a shot if you have one. Most pool owners don't know that they are there or understand what they are for. I wish you well.
 

CJH_KLAS

Member
Jan 10, 2021
6
Henderson, NV
There is not a "spa-side" button, and there are not any connectors with 6 wires.
Also of note, the temperature displayed on the RS8 fluctuates approximately 3 degrees. That is, as the display cycles through its display pattern of date, "Jandy", time, temperature... the temperature displayed will show 41º, then 43º, then 40º, then 43º, etc. It would seem the system believes the outside air temperature is fluctuating, and so it displays this fluctuating temperature, and therefore it sends fluctuating commands to the "freeze protection" with the resulting erratic on/off cycling of the pump.
Both the previous temperature probe as well as the replacement probe are "generic" and not OEM. Could this temperature problem be the result of an incompatible temperature probe...? Does Jandy have their own?
Anyone...?
 

PoolGate

Gold Supporter
TFP Guide
Jun 7, 2017
5,536
Damascus, MD
Pool Size
29000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Jandy Aquapure 1400
I'd say you probably need to get new temp probes. You could try just swapping the 2 to see if the problem goes away.
 

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superuser

Well-known member
Nov 16, 2020
72
Spring, TX
There is not a "spa-side" button, and there are not any connectors with 6 wires.
Also of note, the temperature displayed on the RS8 fluctuates approximately 3 degrees. That is, as the display cycles through its display pattern of date, "Jandy", time, temperature... the temperature displayed will show 41º, then 43º, then 40º, then 43º, etc. It would seem the system believes the outside air temperature is fluctuating, and so it displays this fluctuating temperature, and therefore it sends fluctuating commands to the "freeze protection" with the resulting erratic on/off cycling of the pump.
Both the previous temperature probe as well as the replacement probe are "generic" and not OEM. Could this temperature problem be the result of an incompatible temperature probe...? Does Jandy have their own?
Anyone...?
Sounds to me like you found your smoking gun. The sensor itself, unless simply faulty, shouldn't cause erratic readings. It's a simple thermistor.

Look at the simple things first:
- Are the wiring connections tight?
- Is the connector on the board in good shape? (check for cold solder joints)
- Are the wires in good shape, not nicked or cut?
- Is the temp sensor wire running too close to something that may cause interference (e.g. induced current from a nearby high voltage line)

The temp sensor provides a simple resistance based on temperature, which the board then does a simple measurement of the voltage drop to determine temperature. A generic sensor may or may not be as accurate as OEM (depending on component choice, sensor body construction, and quality of wire), but it would still be stable if all else is good.
 

CJH_KLAS

Member
Jan 10, 2021
6
Henderson, NV
Problem continues...
I replaced the temperature with an OEM Jandy temperature sensor. This did nothing.
All wires are tightly connected and in good shape. The board is in good shape.
I considered the possibility that other wires within the control box might be causing electronic interference, so I moved the temperature sensor wire to another area of the box and exited the box on the other side from it's previous location.
The temperature display now only fluctuates + or - 1 degree instead of + or - 3 degrees. This might be the issue. Has anyone ever used kapton tape to insulate from electronic interference...?
 

MSchutzer

Silver Supporter
Jan 15, 2021
77
Redwood City, Ca
Pool Size
10000
Surface
Plaster
Chlorine
Liquid Chlorine
While Kapton tape provides electrical insulating properties it won’t do anything to provide shielding from electronic interference.

The best advice is to keep the temperature sensor wires away from any other high voltage (AC) wiring in the control box. Make sure it enters the control box in the low voltage side and keep it away from wires from the transformer as the 60 Hz AC signals can couple into the temperature sensor wires. If you do need to cross over a wire carrying an AC signal make sure you do it at right angles.

The worst case for interference coupling is when you run wires parallel to each other in a bundle, especially when some of the wires carry AC signals (relay control signals or any of the relay switched signals)

By moving the temp sensor wiring as you have done you‘ve cut down the interference coupling and improved the situation.

I hope this helps,

Mark
 
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