ThermoMate CZ422NG Natural Gas Tankless Water Heater - 5 GPM, 113,000 BTU, Indoor

Meet the ThermoMate CZ422NG Natural Gas Tankless Water Heater. This compact indoor unit delivers on-demand hot water for the whole house, without bulky storage and with flexible installation options.

Instant, on-demand hot water

With up to 5 GPM and 113,000 BTU, it can serve two showers simultaneously, delivering 105°F water at 2 GPM from an inlet temperature around 65°F. The built-in flow sensor and smart control maintain water within approximately ±1°F for a comfortable experience.

• No waiting time or cold-water shocks thanks to instant heat generation.
• Supports two showers at once with consistent hot water under typical family use.

Safety and reliability

Eight protections guard against common hazards: boil-dry, freeze, flame-out, overheating, over-temperature, pipe blockage, high-temperature lock, and excessive air pressure. Four ceramic heating cores plus frost protection activate automatically when temperatures drop to 41°F (5°C).

• Frost protection helps prevent pipe freezing in cold conditions.
• Comprehensive safety features support safe, long-term operation.

Energy efficiency and cost savings

The heat exchanger uses an oxygen-free copper alloy, delivering superior thermal conductivity and corrosion resistance. It achieves a thermal efficiency of 98% and a UEF of 0.81, reducing energy waste and, in many homes, lowering annual operating costs versus traditional tanks.

• High efficiency reduces energy waste and operating costs.
• Potential savings of around 30% annually compared with traditional tank models.

Smart features and installation

A 3.5-inch LED touchscreen lets you adjust water temperature from 90°F to 140°F and monitor real-time status such as flow, fan operation, and flame status. The unit includes a UL-certified 120V plug and standard 3/4 inch water connections.

• Intuitive control and real-time diagnostics at your fingertips.
• Compact footprint (about 21 in high, 13 in wide, 7 in deep) that frees space in tight areas.

Weather resilience and integration

Engineered with a DC high-speed fan delivering 360 Pa of static pressure and 3,000 RPM, the exhaust is designed for reliability even in high winds. Indoor-only installation uses common 3/4 inch water inlets/outlets, a 1/2 inch gas inlet, a 3 inch vent, and a 120V plug.