NORITZ Tankless Water Heater, Model GQH-40H1FFAI
40kW Gas Combination Boiler, Staged Combustion
- Rated heat input 40 kW
- Rated heat output 36 kW
- Minimum start-up flow 2.5 L/min
- Hot water flow (ΔT = 25°C) 20 L/min
Noritz 40 kW staged-combustion gas combination boilers are aimed at projects that need higher output and more flexible control. Wi-Fi remote control supports real-time adjustments and lets users check operating status easily. These boilers can be applied to heating and hot water systems in private homes, commercial residential buildings, and hotels. Staged combustion also allows the flame to adjust automatically to the load, which helps reduce unnecessary gas use in large-area residential and commercial office heating applications.
- Staged Combustion
- Full Combustion
- Heating temperature settings cover 30–80°C, suitable for different space-heating needs
- Outdoor flue discharge design helps improve efficiency and reduce energy use
- Hot water stays more consistent during multi-point use, even when outlets run at the same time
- Noise is kept low, with operation down to 42 dB(A)
- Active anti-freeze protection supports stable winter operation
| Model | GQH-40H1FFAI |
| Rated heat input | 40 kW |
| Rated heat output | 36 kW |
| Minimum heating output | 14 kW |
| Minimum DHW output | 7.8 kW |
| Minimum start-up flow | 2.5 L/min |
| Thermal efficiency | ≥89% |
| Hot water flow (ΔT = 25°C) | 20 L/min |
| Dimensions (H × W × D) | 738 × 510 × 350 mm |
| Weight | 41 kg |
| Water-flow servo motors | 0 |
| Staged combustion | Yes |
| Circulation pump | 1 |
| 0.5°C temperature step control | No |
| Heating temperature range | 30–80°C |
| Hot water temperature range | 35–60°C |
| Noise level (sound power / sound pressure) | ≤53 / ≤39 dB |
| Wi-Fi | Yes |
Combustion Fan
A fixed-speed fan supports stable operation and broad compatibility. Reliable start-up performance makes it suitable for higher-load conditions.
Electronic Controller
Provides accurate temperature control and efficient operation. Includes safety protections, convenient smart functions, and fault diagnosis for easier maintenance.
Sealed Combustion Chamber
Side panels use insulating and sound-damping materials to reduce noise and help prevent friction and resonance. H-series gas boilers can operate at noise levels as low as 42 dB(A).*
Noritz Water Pump
Designed for quiet operation to improve comfort. Features built-in self-protection to help reduce fault risk.
Sectional Valve
Supports staged combustion control for finer, more precise flame adjustment.
Five-Stage Heat Exchanger Design
Keeps the unit compact while improving heat absorption. Larger main tubes and a longer heat-exchange path help capture heat more effectively.
Italian SIT Proportional Valve
Precisely regulates gas flow and pressure with fast response. Helps optimize combustion efficiency and reduce energy use.
Expansion Tank
Balances pressure changes in the water circuit and compensates for volume shifts as temperatures change. Helps protect components and supports stable operation.
- Component Overview
- Installation Dimensions
- Radiator heating: Set within 30–80°C to match different rooms and seasonal needs
- Shower comfort: Hot water stays stable, with temperature changes around ±1°C
- Floor heating: Quick warm-up in typical use, often about 30 minutes
- Kitchen bathroom: Multi-point hot water use stays steady, so outlets can run together with less interference
Noritz is a Japan-based manufacturer with a long track record in hot water and heating technology. With over 70 years of R&D experience, Noritz supplies energy-saving, high-output hot water and heating systems for projects ranging from private residences to commercial buildings. Partners choose Noritz for competitive thermal solutions and reliable global supply chain support.