Metering for performance

This information only applies if you have a heat pump. If you don’t have a heat pump then go to the metering for payment section to see if your plant needs to be metered for payment.

The Government has introduced changes to the Domestic RHI Regulations. Changes were introduced in two stages. The first stage of changes to the Domestic Scheme came into effect on 20 September 2017. The second stage came into effect on 22 May 2018.

For more information about changes to the scheme and what they mean to you, please see our changes to the scheme webpage and our Factsheet: Important changes to the Domestic RHI Scheme.

After 22 May 2018, all new Domestic RHI applications for heat pumps are required to have an electricity meter arrangement that measures the electricity consumed by it to generate heat.

To receive Domestic RHI payments, you must ensure your meters are properly calibrated, installed and in good working order.

To comply with this requirement, your MCS installer needs to install at least one of the following electricity meter arrangements:

The meter(s) will be required to record and display:

  • electricity used by the plant to generate heat;
  • electrical input into any supplementary electric heater controlled by the same control system as the heat pump; and
  • electrical input into any immersion heater for a domestic hot water cylinder where the immersion heater is controlled by the same control system as the heat pump.

This will need to be added on your MCS Certificate. For full details and examples, please read our Essential Guide to Metering.

Note: If there are multiple supplementary or immersion heaters controlled by the same control system as the heat pump, a single meter can be installed to record the total combined electrical input; or, each heater can be metered separately. Metering input to each heater separately could help monitor the efficiency of the heat pump and identify if there is an issue with an individual immersion heater/supplementary heater. Each meter is also required to have a label which identifies the plant or component that’s being metered.

In the majority of cases you’ll only require a single meter, but it’s possible that more meters may be needed. In some cases up to two further meters could also be required to measure the domestic hot water immersion heater. This will need to be added on your MCS Certificate. For full details and examples, please read our Essential Guide to Metering.

The metering for performance requirement is aimed at making the measurement of performance of the heating systems possible. It’s separate from, and different to, any requirement to be metered for RHI payments. Unless you are also required to have meters for payment, Domestic RHI payments will still be based on the heat demand listed on your Energy Performance Certificate (EPC), up to the relevant heat demand limit.

You won’t be required to submit electricity meter readings to us unless you have meters for payment. However, BEIS recommends you monitor the electricity (kWh) your heating system uses on a regular basis and speak to your MCS installer if your heat pump isn’t performing as efficiently as you’d expect.

If you commissioned your plant before these changes came into effect but applied to the scheme after, you’ll need an MCS installer to install electricity meters before you can make an application to the Domestic RHI scheme.

For more detailed information, please read our Essential Guide to Metering.