How to Fix the blb Error Code & Replace Your Sundance® CLEARRAY® XL UV-C Bulb

If your Sundance® Spa topside control panel is flashing the blb error code (or showing a bulb replacement reminder), don't panic. This isn't a mechanical breakdown or heater failure; it is simply your hot tub’s built-in maintenance timer letting you know that your CLEARRAY® XL UV-C bulb has reached the end of its 365-day lifespan.

Even if the bulb appears to be lit or glowing blue, UV-C output degrades over 12 months, reducing its ability to neutralize waterborne contaminants.

This guide covers why replacing your UV bulb is critical, a step-by-step DIY installation walkthrough, how to reset the error code on your control panel, and how pairing UV sanitation with the right chemical system keeps your water crystal clear.

What Does the CLEARRAY® System Do?

The CLEARRAY® Water Purification System uses natural UV-C light technology to sanitize your spa water as it passes through the filtration circuit. It neutralizes 99.9% of waterborne pathogens on contact, which:

• Dramatically reduces the amount of harsh chemical sanitizers (like chlorine or bromine) needed.
• Eliminates heavy chemical odours and skin/eye irritation.
• Keeps water feeling silky smooth and easy to balance.

To maintain maximum sanitizing efficiency, the bulb must be replaced once every 12 months.

What You’ll Need Before Starting

• Replacement Bulb: CLEARRAY XL UV-C Replacement Bulb 240V (Part #6472-841)
• Tools: Screwdriver (Phillips head), pair of latex/nitrile gloves (or a clean cloth).
• Important Safety Note: Never touch the glass of the new UV bulb with bare fingers. Skin oils create hot spots on quartz glass, significantly reducing the bulb's lifespan and potentially causing premature failure.

Step-by-Step Replacement Guide

1. Power Down the Spa: Safety Prerequisite.
   Turn off the main GFCI breaker at your outdoor electrical panel. Never attempt to open the control enclosure or replace electrical components with power supplied to the hot tub.
2. Access the CLEARRAY® Unit:
   Remove the cabinet panel directly below the topside controller. Locate the stainless steel CLEARRAY® canister attached near the control box.
3. Remove the Protective Enclosure Cover:
   Unscrew the protective shroud/enclosure cap from the top of the CLEARRAY® vessel and slide off the protective rubber boot to expose the bulb connector cable.
4. Extract the Old Bulb:
   Gently unplug the wire harness connector from the top of the old bulb. Carefully slide the expired UV bulb straight up and out of the internal quartz tube. Inspect the quartz sleeve for any mineral scaling or moisture.
5. Install the New 6472-841 Bulb:
   Put on gloves. Take your new CLEARRAY XL UV-C Bulb (6472-841) and align the pins with the cable harness connector until firmly seated. Slide the new bulb down into the quartz tube, replace the protective rubber boot, and re-fasten the enclosure cap.
6. Restore Power & Reset the Timer:
   Turn the GFCI breaker back ON. Follow the control panel instructions below to reset the 365-day timer and clear the blb alert.

How to Reset the blb Error Code

Depending on your Sundance® Spa Series (980 Series, 880 Series, 780 Series, or 680 Series), the timer reset process varies:

• Glass Touchscreen Models (980 & 880 Series):
• Navigate to Settings > Water Care / CLEARRAY > Select Reset UV Timer and confirm.
• Digital Push-Button Models (780 & 680 Series):
• Press and hold the Jets 1 and Cooler (Down) buttons simultaneously for 3 seconds. Scroll through the menu until UV or 0 appears, then press the Warmer (Up) button to reset the counter back to 365 days.

Maximize Water Quality with the Right Water Care System

While the CLEARRAY® system handles microorganism neutralization, maintaining balanced water and preventing scale buildup on your UV quartz sleeve requires regular chemical maintenance.

At Main Street Pool & Spa, we recommend pairing your CLEARRAY® system with the Mineraluxe Water Care System:

• Weekly Mineral Treatment: Use the Mineraluxe 2-Part Kit along with Mineraluxe Cubes to prevent scale buildup on your heater and UV quartz tube.
• Deep Clarification: Apply Mineraluxe Oxygen weekly to cleanse organic waste and keep water sparkling.
• Explore Full Chemical Lineup: Browse our complete selection of Hot Tub Chemicals for balancing pH, alkalinity, and hardness.

Need Help or Looking to Upgrade?

If you prefer to have a certified technician handle your bulb replacement or perform a full seasonal spa tune-up in Uxbridge and Durham Region, visit our Hot Tub Service & Repair page to book an appointment.

Looking to replace hardware or upgrade your spa experience?

• Browse OEM components in our Hot Tub Parts Collection.
• Explore new energy-efficient models in our full Sundance Spas Collection.