Hot Water Recovery Time Calculator

Calculate hot water cylinder recovery time from power, or required power from desired recovery time.

Volume (Litres)

Temperature Difference (ΔT °C)

Power (KW)

Recovery Time

23.31

minutes

Formula Reference

Time (minutes) = (Volume × ΔT) / (14.3 × Power)
Volume = cylinder volume in litres
ΔT = temperature difference in °C
Power = heating power in kilowatts (KW)
14.3 = constant factor for this calculation

Volume (Litres)

Temperature Difference (ΔT °C)

Recovery Time (Minutes)

Required Power

23.33

kilowatts (KW)

Formula Reference

Power (KW) = (Volume × ΔT × 4.2) / (Minutes × 60)
Volume = cylinder volume in litres
ΔT = temperature difference in °C
Minutes = desired recovery time in minutes
4.2 = specific heat capacity of water (kJ/kg·°C)
60 = conversion factor (seconds per minute)

Important: This calculator provides indicative hot water recovery estimates only. Actual performance may vary based on system efficiency, heat losses, and real-world conditions. Always consult with a qualified heating engineer for your specific installation requirements.