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HDC1500i (59kW) Commercial Condensing Gas Fired Water Heater

HDC1500i (59kW) Commercial Condensing Gas Fired Water Heater

Rinnai HDC1500i Condensing Water Heater

The condensing water heater process delivers up to 105% net thermal efficiency, which translates to significant energy savings when compared to their conventional counterparts. also ideal for temporary or emergency hot water. 

  • Energy efficient -105% net efficiency*
  • Saves space, water, energy and time
  • Limitless application
  • Compact design with internal and weather-proof external models
  • Renewables ready when you are - Suitable for use as a temperature booster for solar thermal and heat-pump
  • Rinnai commercial condensing water heaters are available in both Natural Gas and LPG
  • LPG commercial water heaters are delivered to site LPG enabled.

* In accordance with BS EN 677

W1500IKM-NAT : Natural Gas Water Heater
W1500IKM-LPG : LPG Water Heater


Ancillaries Commercial Brochure HDC1500i ERP HDC1500i Product Fiche

 Status Monitoring For Easier Diagnostics

The status has three conditions

  1. The water heater is off (no water flowing):The LED is blank
  2. The water heater is on (heating water ):The LED displays the set temperature
  3. The water heater should be on, but is not (water flowing, heater is not on):The LED will flash a diagnostic code

The LED will flash a diagnostic code.

'Rinnai condensing water heaters will never run out of hot water'


Installation Internal
Fuel Natural Gas or LPG*
Control Modulating
Gas consumption
Natural gas 59.5 kW max
Propane 58.8 kW max
Exhaust type Forced room sealed
Ignition Electronic
Burner Stainless steel
Low NOx Less than 50ppm
Height 721.6mm
Width 470mm
Depth 256.9mm
Weight 31 kg
Water flow rate 1.5** to 37L/min
Minimum operating pressure 1.0 Bar
Noise level 50 db(A)
Gas 3/4 bsp
Water inlet 3/4 bsp
Water outlet 3/4 bsp
Condensate outlet 1/2 bsp
Electrical Supply 230 AC 50 Hz 1ph

* Separate models available for Natural gas or LPG fuel.

** Minimum flow rate based on temperature set point and inlet conditions.

'The Rinnai continuous flow water heaters represent our commitment to delivering the best systems available in the world today' 

Additional Information

Gas Usage 5.7m3
Gas usage LPG 4.2kg/hr
Turn down 59.5 - 2.8 kW

HDC1500i as a Solar Booster

The HDC1500i will deliver 16 l/min @ 50˚C Rise using 5.4m³ gas.
If the incoming water temperature is increased, the following savings are achieved:

Flow rateEnergySaving on gas
16l/min @ 40°C Rise 44.7kW 21% (1.2m3)
16l/min @ 30°C Rise 33.5kW 21% (1.2m3)
16l/min @ 20°C Rise 22.3kW 40% (2.2m3)
16l/min @ 10°C Rise 11.0kW 61% (3.5m3)


A 20 tube panel will yield approx 1439kW/yr* so a fairly standard arrangement of 3 panels would yield 4317kWh/yr

Consequently this equates to 4317kW free energy or the equivalent of 401.6 m³ gas per annum

*This is based on an installation in Southampton, south facing and an inclination of 45˚

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