Product Description

The Balboa Auxiliary Slave Heater – 3.0 kW (SKU 58133) is a powerful inline heater designed to supplement the main heater in larger spas and swim spas. Installed in‑line on the spa’s plumbing circuit, it provides an additional 3kW of heating output, making it ideal for high‑capacity systems requiring faster heat‑up times and improved temperature stability.

Built with a durable Incoloy 800 heating element, the 58133 heater is engineered for long‑term reliability and superior corrosion resistance. It connects directly to 2-inch plumbing using the supplied unions and gaskets for a secure, leak‑free installation. This unit features a built‑in high‑limit safety sensor, while flow detection and temperature regulation are controlled by the master Balboa spa pack. 

Fully compatible with a wide range of Balboa M7 systems—including GS500/GS501/GS510/GS523, GL2000, GL2001, and BP series controllers—the Auxiliary Slave Heater integrates seamlessly by connecting via its dedicated control cable. When the main heater activates, the slave heater automatically engages to deliver a combined heating power of up to 6kW, perfect for large‑volume water spas and swim spas needing increased thermal performance. 

Whether you're replacing an existing unit or upgrading your spa system to achieve faster, more efficient heating, the Balboa 58133 Auxiliary Heater offers reliable performance, wide system compatibility, and robust construction trusted across the spa industry.