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Heat pump vs boiler: practical guide
This guide explains how to use the Count.ie heat pump vs boiler. Compare annual fuel demand, running cost and simple payback. Follow the inputs, method and worked example below, then compare your own scenario.
Guide written .
Open the Heat pump vs boiler calculatorWhat to prepare
- Use meter readings, bills, equipment specifications and actual tariff periods where possible.
- Separate power in kW from energy in kWh and daily use from annual use.
- Identify whether efficiency, standing charges and losses are included in the chosen model.
Understand the inputs
The calculation method
Heat pump input = heat ÷ COP. Boiler input = heat ÷ efficiency. Payback = extra capital ÷ positive annual saving.
Worked example
Illustrative inputs and their result.
Example inputs
- Annual useful heat (kWh)
- 12000
- Seasonal heat pump COP
- 3.5
- Electricity price (€/kWh)
- 0.3
- Boiler seasonal efficiency (%)
- 85
- Boiler fuel price (€/input kWh)
- 0.1
- Extra installation cost (€)
- 5000
Calculated example result
- Annual Saving
- €383.19
- Simple Payback Years
- 13.05 years
How to interpret the result
Energy consumption and money saved are different outputs. Results based on entered prices or efficiencies are scenarios, not a performance guarantee, installer quote or measured emissions assessment.
Use the same demand and time horizon for each option. Test a less favourable tariff, lower efficiency or lower use to see how sensitive the estimated saving is.
Common mistakes to avoid
- Do not count the same efficiency loss twice.
- Keep standing charges and unit charges separate when the model distinguishes them.
- Check seasonal demand, export restrictions and tariff assumptions before extrapolating.
Assumptions and sources
Seasonal COP is an assumption, not a product guarantee. Excludes grants, finance, maintenance differences and temperature-dependent performance.
If your case falls outside this scope, use a more suitable calculator or contact us about an unclear method.