Zilmet ZEP-1 Stainless Steel Thermal Expansion Tank (1/2" NPT) – For Tankless

Overview

Protect your tankless water heater and plumbing system from pressure spikes caused by thermal expansion. This stainless steel thermal expansion tank is built for durability and features a UV-resistant design that’s suitable for outdoor installations.

Key Benefits

• Protects critical components: Helps safeguard the heat exchanger and valves from excess pressure.
• Built to last: High-quality stainless steel construction resists corrosion.
• Outdoor-ready: UV-resistant design stands up to sun exposure.
• Compact footprint: Easy to add on most tankless installs.

Suggested Applications

• Tankless water heater systems (residential & light commercial)
• Closed or partially closed plumbing systems where thermal expansion can occur

Specifications

What’s Included

• Stainless steel thermal expansion tank
• Installation guide (if provided by manufacturer)

Installation Notes

• Install on the cold-water supply per local code; orient per manufacturer instructions.
• Pre-charge and size per system requirements and inlet pressure.
• Use thread sealant rated for potable water.

Compatibility

Works with most major tankless brands (Navien, Noritz, Rinnai, Takagi, etc.). Always size and verify connection before purchase.

Frequently Asked Questions

Do I need an expansion tank with a tankless heater?
If your plumbing system is closed or partially closed (e.g., with a check valve or PRV), an expansion tank helps prevent pressure spikes that can damage components.

Is this OK outdoors?
Yes, the design is UV-resistant. Protect fittings and follow local code for outdoor installations.