Hayward ColorLogic Light Flickering or Dimming
Quick Summary
- Flickering or dimming is almost always a voltage problem — insufficient voltage reaching the light at the cord junction point due to transformer issues, bad connections, or voltage drop from cord length.
- First step: power cycle the lights off for at least 2 minutes. If the issue clears on restart, it was a transient condition. If it returns, proceed with voltage measurement.
- Required voltage at the junction point: 12–14VAC for 50-foot cords, 13–14VAC for 100-foot cords, exactly 14VAC for 150-foot cords.
- Mixing 150-foot cord lights with a junction box is not permitted — 150-foot cords require 14VAC and can only achieve this without a junction box adding resistance between transformer and light.
Why ColorLogic Lights Flicker or Dim
Hayward ColorLogic LED lights require a stable 12–14VAC supply at their cord's junction point to operate correctly. When voltage falls below this range — even briefly — the light's internal driver detects insufficient power and responds by dimming, flickering, or cycling off and on. The LED will flash if the supplied voltage is too low, which is the light's built-in protection response signaling a power issue.
The three most common causes are: low transformer secondary voltage, a bad or corroded junction box connection, and voltage drop caused by cord length or undersized low-voltage wiring between the transformer and the junction box.
Step-by-Step Diagnosis
Step 1: Power cycle the lights
Turn the lights off completely — either through the breaker or through the controller — for a minimum of 2 minutes. Then restore power. If the flickering or dimming clears after the power cycle and the lights run normally, the issue was a transient voltage sag or a timing hiccup in the light's initialization. Monitor over the next few days. If it recurs, proceed with voltage measurements.
Step 2: Verify voltage at the junction box (12–14VAC)
With lights running and flickering, use a multimeter to measure AC voltage at the junction box — the point where the transformer low-voltage output connects to the light cords:
- For 50-foot light cords: you need 12–14VAC at the junction point.
- For 100-foot light cords: you need 13–14VAC at the junction point.
- For 150-foot light cords: you need 14VAC at the junction point, and there must be no junction box between the transformer and the light (direct wiring only).
If voltage at the junction box is below the minimum for your cord length, the problem is upstream — either the transformer secondary is not outputting enough voltage, or there is too much resistance in the wiring between the transformer and the junction box. Proceed to step 3.
If voltage at the junction box measures within range but lights still flicker, call Hayward technical support — there may be a localized connection issue between the junction box and the specific light's cord connector, or the light itself has an internal driver fault.
Step 3: Verify transformer secondary voltage (14VAC)
Measure directly across the transformer secondary output terminals. You should read 14VAC. If you read less than 14VAC — especially under load with all lights connected — the transformer is either failing, undersized for the number of lights, or incorrectly wired.
- An overloaded transformer will measure closer to 14VAC with no lights connected but drop significantly under full load. Connect lights one at a time while measuring secondary voltage to identify at what point it drops.
- If secondary voltage is low even with no secondary load, the transformer is failing and should be replaced.
Step 4: Verify transformer primary voltage (120VAC)
If secondary voltage is low, check primary voltage before replacing the transformer. If the primary is also low — say, 108VAC instead of 120VAC — the problem is the utility supply, not the transformer. A primary voltage below 120VAC will proportionally reduce secondary output. Contact your electricity supplier if primary voltage is consistently low at the transformer terminals.
Step 5: Check for a break in the line or bad connection
If transformer secondary is correct (14VAC) but junction box voltage is low, there is resistance in the wiring run between transformer and junction box. This can be caused by a loose splice, a corroded wire nut, undersized wire gauge for the distance, or a partial break in the conductor. Inspect all connections in the run. Tighten or replace any suspect splices. If no physical problem is found, use a wire gauge calculator to verify the conductor is sized correctly for the distance and current draw.
Frequently Asked Questions
The light flickers only after running for an hour or more. What is happening?
A thermal-related flicker usually points to the transformer overheating under sustained load and its output dropping as it warms up. Feel the transformer case after an hour of operation — if it is hot to the touch, the transformer is either undersized for the load or has poor ventilation. Check that the transformer is not enclosed in a tight space and verify the total wattage draw does not exceed its rating.
Only one of my three lights flickers while the others are steady. What does that mean?
If only one light flickers while others on the same circuit are steady, the problem is specific to that light's cord or its connection at the junction box. Disconnect and reconnect that light's cord at the junction box, looking for a loose or corroded connection. If the connection is clean and tight and the light still flickers, swap it with a neighboring light to see if the problem follows the light (fixture failure) or stays at that position (wiring issue).
My lights dim only when multiple lights are on together. What causes that?
Dimming under full load is a classic sign of transformer overloading or undersized low-voltage wiring. Calculate the total wattage: each ColorLogic UCL light draws approximately 65W. If your transformer is rated at 150W and you have three lights (195W total), it is overloaded. Reduce the number of lights per transformer or install an additional transformer to distribute the load.
Can I fix voltage drop by adjusting the transformer output?
Some Hayward transformers have multiple tap settings that allow you to configure the output between 12VAC and 14VAC. If your junction box voltage is measuring low due to wiring resistance, setting the transformer to its highest output tap (14VAC) may compensate for the drop. Consult your transformer's installation guide for tap adjustment instructions. Always verify the junction box voltage with a meter after making adjustments.
Why do 150-foot cord lights require direct connection with no junction box?
Every connection in the low-voltage circuit adds resistance, which causes voltage drop. A 150-foot light cord has significant inherent resistance over that length. To arrive at the light with sufficient voltage (the minimum 12VAC the LED driver needs), the transformer must output the full 14VAC and the wiring must introduce as little additional resistance as possible. Adding a junction box inserts at least one additional splice resistance into the circuit, making it impossible to maintain adequate voltage at the light end. Hayward's specifications explicitly prohibit junction boxes on 150-foot cord installations.