Jandy | R0621900 | Pro Series TruClear Chlorine Generator Installation & Winterizing Cap
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The Jandy R0621900 Installation & Winterizing Cap is the genuine Zodiac/Jandy replacement cap for the Pro Series TruClear® Chlorine Generating System. When the TruClear electrolytic cell is removed for off-season storage, cleaning, or during initial plumbing and pressure testing, this cap threads into the cell housing to seal the circulation loop so water can keep flowing while the cell is safely out of the system.
Built from corrosion-resistant polymer with a clear center window and a factory O-ring, the cap hand-tightens with its large grip knob—no tools required. Keep one on hand so your salt cell never sits in freezing water and your TruClear housing stays protected year after year.
Key Features
- Genuine Jandy / Zodiac OEM part – model R0621900 (alt. ref. JDY-45-9881)
- Fits the Jandy Pro Series TruClear® salt chlorine generator cell housing
- Seals the housing so the cell can be removed for winterizing, cleaning, or storage
- Doubles as an installation cap for plumbing and pressure testing before the cell is installed
- Corrosion- and salt-resistant construction with clear viewing window
- Large ergonomic knob for tool-free, hand-tight installation and removal
- O-ring included for a watertight seal
- Compact and lightweight – easy to store with your winterizing supplies
Specifications
| Brand | Jandy (Zodiac Pool Systems) |
| Part Number / MPN | R0621900 |
| UPC | 052337072397 |
| Product Type | Installation & Winterizing Cap |
| Compatible With | Jandy Pro Series TruClear® Chlorine Generating System (TruClear cell housing) |
| Material | Corrosion-resistant polymer with clear window |
| Includes | Cap with O-ring |
| Color | Black / Clear |
| Weight | 1.1 lb |
| Package Dimensions | 8.13 x 8.13 x 8.25 in |
| Condition | New |
Frequently Asked Questions
What is the Jandy R0621900 used for?
It seals the TruClear cell housing whenever the salt cell is removed—most commonly for winterizing in freezing climates, but also for acid cleaning the cell, extended storage, or pressure testing new plumbing before the cell is installed.
Which Jandy systems does this cap fit?
The R0621900 is designed for the Jandy Pro Series TruClear® chlorine generating system cell housing. It is not intended for AquaPure®, Nature2® or other Jandy/Zodiac sanitizers.
Do I need to remove my TruClear cell for winter?
Jandy recommends removing the cell before freezing temperatures so trapped water cannot expand and crack the cell. Install the R0621900 cap in its place so the system stays sealed.
Does it come with an O-ring?
Yes. The cap ships with a factory O-ring installed on the underside. Lubricate it lightly with a silicone-based lubricant before installation.
Do I need tools to install it?
No. The large knob is designed to be hand-tightened only. Over-tightening with tools can damage the threads or O-ring.
Is this a genuine Jandy part?
Yes. AppaeTech Pool Supply is an authorized dealer and ships only genuine Jandy / Zodiac OEM parts.
WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.