RHI Calculator - OMNIE | The Whole House System

Renewable Heat Incentive Calculator

This tool enables you to calculate the approximate RHI that would be paid for your domestic Heat Pump installation over a 7 year period. This is a government backed scheme that applies to MCS approved installations. You can find further details and criteria under the MCS explained documents on this website.

The tool provides a comparison to using a conventional fossil fuel (oil and mains gas) heating system versus a heat pump installation. Select the preferred option for ground or air source heat pump, depending on suitability. Use the sliders to input the data that is applicable for your property.

Heat Pump

Type of Heat Pump

GSHP: Ground Source Heat pump, extracts energy from the ground, is reliant on horizontal or vertical collectors
ASHP: Air Source heat Pump, uses the ambient air temperature to provide the energy

Estimated yearly Space heating requirement

Unit of energy equivalent to one kilowatt (1 kW) of power expended for one hour


Flow Temperature

Flow temperature deg C = the flow temperature in the heating system required to meet the heat losses of the building

Cost of Electicity £/kWh


Comparative Conventional Boiler

Type of Fossil Fuel

Oil Consumption


Oil Consumption to kWh

1 litre of oil = 11.8kWh


Heat Load

Gas/Oil Boiler based on 85% efficiency


Gas Consumption (kWh)


Cost of Gas £/kWh


Your Results

RHI Payments

COP is

Percent kWh Renewable is

RHI Payments per year

RHI: Renewable Heat Incentive

Total RHI payments over 7 years


Fuel Savings

Annual Savings



Existing properties

If you have an existing property and looking to replace the entire heating system you can use your annual energy usage in kWh on you utility bill, or the number of litres for oil. Working on a flow temperature of 50 deg C the radiators can be sized on this flow temperature. Use the sliders to replicate your energy usage for existing, and the new heating system using a heat pump.

New build/ refurb

Use the space heating energy demand on the Energy Performance Certificate (EPC) to determine the RHI payment. This can be found on the bottom of the EPC document which is generated from your Standard Assessment Performance (SAP) document, this will provide an accurate kWh to calculate the RHI. The typical flow temperature for new build/ refurb are 35-45 deg C depending on the insulation levels and type of heating system used.

General notes

This tool provides an indication of the RHI and shouldn’t be used for the basis of securing finance or making an investment in this technology. Please note this does not factor equipment installation costs or any other overheads relating to the heating system