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Understanding the RHI ‘Plant Replacement’ legislation

GlenFarrow biomass boiler

Four years ago, Ofgem implemented new legislation for the non-domestic RHI (Renewable Heat Incentive) scheme called ‘Plant Replacement”. Under this new legislation, you are able to replace your biomass boiler and retain your existing RHI tariff. So, if your boiler is currently accredited to the RHI scheme, you would be able to change your boiler without having to miss out on those monthly payments.

Good news, right? Although this legislation doesn’t come without its limits. There are a few things to consider when replacing your biomass boiler – especially when it comes to the kW capacity. Let’s break it down….

Increasing capacity

Let’s say you currently have a 200kW biomass boiler. If you were looking to replace your boiler with a higher capacity appliance (400kW for example) your tier 1 and 2 rates will still remain the same as the original accreditation, however, your tier 1 threshold will be based on the original boiler size of 200kW.

Decreasing capacity

If your current system is now too large for your requirements, you can also replace your boiler with one that has a lower kW capacity. Although, this means that your tier 1 tariff rate and threshold will now be reduced and based on the new lower plant capacity.

Changing model/boiler type

This legislation also allows for you to change the type of biomass boiler you have. For example, you can swap a batch-fed system to a fully automatic boiler or vis-versa.

Benefits of plant replacement:


Changing to an automatic system helps to keep a more consistent boiler temperature – potentially uplifting your current RHI payments.


Upgrading to a more efficient boiler could help to reduce your fuel consumption and help you to cut fuel costs.

Reduced manual labour

If you currently have a batch-fed biomass boiler, upgrading to an automated system means you will be able to reduce the amount of labour time spent fuelling the boiler – saving you valuable time.

How can GF help?

  • Our in-house RHI consultant can assist with all RHI work to help the transition move as smoothly as possible
  • We are experts in the field with many years of experience and are able to offer advice on multiple upgrade options
  • We offer a full turn-key service: supply, replace, install and commission

Take a look a one of our plant replacement projects we completed for one happy customer: https://glenfarrow.co.uk/case-studies/r-hutt-partners/

For more information about the RHI Plant Replacement legislation please call David Taylor on 01775 722327.