Gas
Low-NOx Condensing Gas Storage Water Heater – PRO Series
- Thermal efficiency ≥107%
- NOx < 30 mg/m³
- 30–99 kW
Gas
Commercial Gas Storage Water Heater – CLASSIC Series
A straightforward atmospheric-combustion gas storage water heater for small and mid-sized businesses that need a 24-hour hot water supply, such as guesthouses, budget hotels, spas and care centers.
- 22–99 kW
- 220–360 L tanks
- Pressure rating 1.1 MPa
- Indoor & outdoor
Key features
Efficiency
SPOILER-FLUE turbulent heat exchange technology with thermal efficiency of up to 87% (≥93% for the 22 kW model). Thick polyurethane insulation and a specially designed flue baffle reduce standby flue heat loss by 60%.
Safety
Two-stage ignition with automatic gas valve control. Four layers of protection: thermostat, high-temperature limit, over-temperature protection and T&P valve. Pressure rating up to 1.1 MPa.
Quiet operation
Atmospheric combustion with no combustion fan required, for low operating noise.
Installation
Suitable for indoor and outdoor installation; an optional forced-draft fan is available.
Technical specifications
Indoor models
| Model | RSTQ22-220 | RSTQ32-320 | RSTD50-360 | RSTD73-360 | RSTD99-320 |
|---|---|---|---|---|---|
| Storage capacity (L) | 220 | 320 | 360 | 360 | 320 |
| Thermal efficiency | ≥93% | ≥87% | ≥87% | ≥87% | ≥87% |
| Rated heat input (kW) | 22 | 32 | 50 | 73 | 99 |
| Gas consumption (m³/h) | 2.2 | 3.2 | 5.0 | 7.3 | 9.9 |
| Electric power (W) | 65 | 65 | 25 | 25 | 25 |
| Rated working pressure (MPa) | 1.1 | 1.1 | 1.1 | 1.1 | 1.1 |
| Temperature setting range (°C) | 30–80 | 30–75 | 30–75 | 30–75 | 30–75 |
| Hot water output at Δt = 25 °C (L/h) | 619 | 900 | 1,500 | 2,190 | 2,967 |
| Hot water output at Δt = 35 °C (L/h) | 442 | 643 | 1,071 | 1,564 | 2,120 |
| Hot water output at Δt = 55 °C (L/h) | 281 | 409 | 682 | 996 | 1,348 |
| Inlet/outlet pipe diameter | DN32 | DN32 | DN50 | DN50 | DN50 |
| Flue outlet diameter | Φ60 | Φ60 | Φ200 | Φ200 | Φ200 |
| Net weight (kg) | 195 | 297 | 427 | 440 | 450 |
| Total height (mm) | 1750 | 1900 | 2200 | 2200 | 2200 |
| Body diameter (mm) | 520 | 630 | 710 | 710 | 710 |
Outdoor models
| Model | RSTW50-360 | RSTW73-360 | RSTW99-320 |
|---|---|---|---|
| Storage capacity (L) | 360 | 360 | 320 |
| Thermal efficiency | ≥87% | ≥87% | ≥87% |
| Rated heat input (kW) | 50 | 73 | 99 |
| Gas consumption (m³/h) | 5.0 | 7.3 | 9.9 |
| Electric power (W) | 25 | 25 | 25 |
| Rated working pressure (MPa) | 1.1 | 1.1 | 1.1 |
| Temperature setting range (°C) | 30–75 | 30–75 | 30–75 |
| Hot water output at Δt = 25 °C (L/h) | 1,500 | 2,190 | 2,967 |
| Hot water output at Δt = 35 °C (L/h) | 1,071 | 1,564 | 2,120 |
| Hot water output at Δt = 55 °C (L/h) | 682 | 996 | 1,348 |
| Inlet/outlet pipe diameter | DN50 | DN50 | DN50 |
| Gas connection | DN20 | DN20 | DN20 |
| Safety valve / drain valve | DN25 / DN25 | DN25 / DN25 | DN25 / DN25 |
| Flue outlet diameter | Φ200 | Φ200 | Φ200 |
| Net weight (kg) | 427 | 440 | 450 |
| Waterproof rating | IPX4 | IPX4 | IPX4 |
Data as published by OTTMEL. Specifications may change; please confirm the current datasheet with our sales team before ordering. Gas type, voltage and other market-specific requirements should be confirmed for each project.
Typical applications
- Guesthouses and budget hotels
- Spas and foot-massage centers
- Infant swimming centers
- Postnatal care centers
- Small commercial buildings
Related products
Gas
Low-NOx Gas Storage Water Heater – PLUS Series
- Thermal efficiency up to 98%
- NOx < 30 mg/m³
- 400 L tank
Gas
Condensing Premix Storage Fire-Tube Boiler
- 240–700 kW
- NOx 22.3–24.7 mg/m³
- Modulation up to 12:1
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