---
product_id: 694295900
title: "ETX-90 6-Gallon Non- Potable Expansion Tank for Closed-Loop Systems"
brand: "watts"
price: "$581"
currency: NZD
in_stock: true
reviews_count: 13
category: "Watts"
url: https://www.desertcart.nz/products/694295900-etx-90-6-gallon-non-potable-expansion-tank-for-closed
store_origin: NZ
region: New Zealand
---

# Pre-charged at 12 psi 6-gallon capacity Max pressure 75 psi ETX-90 6-Gallon Non- Potable Expansion Tank for Closed-Loop Systems

**Brand:** watts
**Price:** $581
**Availability:** ✅ In Stock

## Summary

> 🛠️ Upgrade your hydronic system with Watts — pressure control that just works!

## Quick Answers

- **What is this?** ETX-90 6-Gallon Non- Potable Expansion Tank for Closed-Loop Systems by watts
- **How much does it cost?** $581 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.nz](https://www.desertcart.nz/products/694295900-etx-90-6-gallon-non-potable-expansion-tank-for-closed)

## Best For

- watts enthusiasts

## Why This Product

- Trusted watts brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Pressure-Smart Design:** Keeps system pressure below relief valve setting to prevent costly leaks
- • **Robust 6-Gallon Capacity:** Handles thermal expansion with ease, reducing system stress
- • **Durable Carbon Steel Build:** Epoxy finish resists corrosion for long-lasting performance
- • **Pre-Charged for Instant Use:** Comes ready at 12 psi to maintain optimal system pressure from day one
- • **Seamless System Integration:** 1/2 inch MNPT connection fits standard piping for quick installation

## Overview

The Watts ETX-90 is a 6-gallon, carbon steel non-potable expansion tank designed for closed-loop hydronic heating systems. Pre-charged at 12 psi and rated for a maximum pressure of 75 psi, it efficiently manages thermal expansion to protect your system from pressure spikes. Its durable epoxy finish and standard 1/2 inch MNPT connection ensure easy installation and long-term reliability in both residential and commercial settings.

## Description

The Watts ETX-60 Non-Potable Water Expansion Tank is used in tandem with your hot water heater to absorb increased water volume resulting from hot water boiler heating and to keep system pressure below the relief setting. Use in closed-loop, non-potable water heating systems. Durable steel tank with 60 psi maximum working pressure

Review: Perfect Fit and Replacement. Watts is what you need!! - Perfect Fit and replacement. Purchased the EXT-30 to replace my failed Flextrol expansion tank purchased 12/2020. Apparently the bladder failed, causing my hydronic heating system to increase pressure causing the pressure pop off valve to drip. The old tank was small, 2.1 gallon size. When researching replacements, I accidently ordered the 4.5 gallon. Thankfully it just barely fit. I have three zones and fingers crossed the larger capacity will endure less stress during the repeating thermo cycling. Watts tank is well built, came pre charged at 12 psi. Spun right on 1/2 mnpt connection. Ordered on Monday, delivered Wednesday and 30 minutes later was installed. Pressures have maintained, no leaks, and zero worries. Btw, I called the plumbing supply store where I purchased the Flextrol in 2020, I believe it was less than 100 bucks, wanted a whopping $150.
Review: Better pricing - Easy to install. Better pricing than from the Big Box store. Good quality.

## Features

- This non-potable water expansion tank is for closed loop hydronic heating system piping to control the thermal expansion of hot water and maintain system pressure below the relief sett of the relief valve
- The carbon steel tank is pre-charged at 12 psi, has a 6 gallon volume, and features a durable expansion membrane preventing minimizes loss of the air change and ensures long and trouble-free life for the system
- Made of carbon steel with epoxy finish, mounts to supply piping, with 1/2 inch MNPT system connection and .302-32 inch charging valve connection for on-site charging of the tank
- Maximum pressure 75 psi and can be used in residential or commercial hydronic heating systems
- Use in tandem with your hot water heater to absorb increased water volume ensuring long and trouble-free life for the system

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0026GOWHS |
| Best Sellers Rank | #221,128 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #322 in Water Heaters |
| Brand | Watts |
| Capacity | 6 Gallons |
| Color | Gray |
| Date First Available | September 6, 2014 |
| Item Weight | 10.63 pounds |
| Item model number | 66607 |
| Manufacturer | Watts |
| Material | Carbon Steel |
| Product Dimensions | 11.5 x 11.5 x 11.5 inches |
| Specification Met | Buy American Act |
| UPC | 098268219364 |

## Product Details

- **Brand:** Watts
- **Capacity:** 6 Gallons
- **Color:** Gray
- **Material:** Carbon Steel
- **Specification Met:** Buy American Act

## Images

![ETX-90 6-Gallon Non- Potable Expansion Tank for Closed-Loop Systems - Image 1](https://m.media-amazon.com/images/I/51WvPeIs8LL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Perfect Fit and Replacement. Watts is what you need!!
*by W**** on March 8, 2025*

Perfect Fit and replacement. Purchased the EXT-30 to replace my failed Flextrol expansion tank purchased 12/2020. Apparently the bladder failed, causing my hydronic heating system to increase pressure causing the pressure pop off valve to drip. The old tank was small, 2.1 gallon size. When researching replacements, I accidently ordered the 4.5 gallon. Thankfully it just barely fit. I have three zones and fingers crossed the larger capacity will endure less stress during the repeating thermo cycling. Watts tank is well built, came pre charged at 12 psi. Spun right on 1/2 mnpt connection. Ordered on Monday, delivered Wednesday and 30 minutes later was installed. Pressures have maintained, no leaks, and zero worries. Btw, I called the plumbing supply store where I purchased the Flextrol in 2020, I believe it was less than 100 bucks, wanted a whopping $150.

### ⭐⭐⭐⭐⭐ Better pricing
*by P***N on August 14, 2025*

Easy to install. Better pricing than from the Big Box store. Good quality.

### ⭐⭐⭐⭐⭐ Worked Just Fine!
*by K***T on December 20, 2025*

OEM. Worked Just Fine!

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---

*Product available on Desertcart New Zealand*
*Store origin: NZ*
*Last updated: 2026-03-03*