Hot Water Calculator

Compare hot water heating costs for different systems and find savings

Hot Water Cost Calculator

Compare different water heating systems and find savings

Usage Details

Recommended: 150L for 3 people

Energy Prices & Settings

Hot Water System Technologies

Understanding different water heating technologies and their efficiency

Electric Systems

95% efficiency, instant hot water, higher running costs but lower installation cost

Gas Systems

85% efficiency, lower fuel costs, requires gas connection and flue

Heat Pumps

300% efficiency, very low running costs, higher installation cost

Solar Thermal

Free energy from sun, 60% coverage typical, requires backup system

Combi Boilers

88% efficiency, combined heating and hot water, space-saving solution

Hybrid Systems

Combine multiple technologies for optimal efficiency and reliability

Hot Water Saving Tips

Simple changes that can reduce your hot water costs significantly

💡

Lower Temperature

Reduce water heating temperature by 5°C to save 10-15% on costs

🚿

Shorter Showers

Reduce shower time by 2 minutes to save 25% on hot water usage

🔧

Fix Leaks

A dripping hot water tap can waste $49-70 per year in energy

  1. 1

    Estimate Daily Usage

    Calculate hot water needs: 35-45 litres per person/day, plus dishwasher (15-25 litres/load) and washing machine (30-60 litres/load). Average UK household: 120-150 litres/day. Track actual usage for 1 week for accuracy.

  2. 2

    Check Current Heater Type

    Identify existing water heater: combination boiler (instant, no storage), system boiler with cylinder (150-300 litres), immersion heater (electric, 70-85% efficient), heat pump (200-300% efficient). Check age - if 10+ years old, consider replacement for efficiency gains.

  3. 3

    Input Energy Rate

    Enter electricity or gas price per unit from utility bill (gas typically £0.06-£0.10/kWh, electricity £0.24-£0.34/kWh). Water heating typically costs £200-£500/year for gas, £400-£800/year for electric. Higher rates make efficient heaters more cost-effective.

  4. 4

    Select New Heater Type

    Compare options: Combination boiler (£1,500-£3,000, instant hot water, space-saving), system boiler with cylinder (£2,000-£4,000, better for multiple taps), heat pump water heater (£2,000-£4,000, very efficient), solar thermal (£4,000-£6,000, 50-70% free hot water). Consider: household size, budget, and efficiency goals.

  5. 5

    Review Savings and Payback

    Calculator shows annual operating cost for each heater type, upgrade cost, and payback period. Consider total lifetime cost (purchase + installation + 15 years energy). Factor in available grants: Boiler Upgrade Scheme covers heat pump water heaters. Combination boilers most popular in UK for space efficiency.

Pro Tip: Use Ctrl+Enter to calculate quickly, or Ctrl+R to reset the form.

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