Standards and legislation applying to heat pump installations

The renewable heating industry is governed by  several bodies, all with sets of guidelines and standards that exist in order to keep standards high, satisfy customer expectations, encourage fair and transparent trading and push for efficient, well designed systems.

There are lots of baffling acronyms, various measures of efficiency, and all in all it can be confusing, especially of you are not an MCS-Accredited installer, or you have limited experience of the industry.

At Kensa we do our best to keep things simple, understandable and fair. We want you to understand why these guidelines exist, so that you can continue to provide a solid, clear service to your clients too.

MCS and MIS 3005

What's MCS?

MCS Stands for the Microgeneration Certification Scheme.

It covers all forms of renewable heat generation - solar PV, solar thermal, biomass and heat pumps.

MCS covers heat pumps up to 45kW output.

It exists to define and uphold standards of manufacture, installation and workmanship across the industry.

In order to claim RHI on a project, the installer must be MCS Accredited for Ground Source Heat Pumps. The product must also be MCS Accredited. Finally, the installation itself must be MCS Accredited.

All Kensa's products (with the exception of some 3-phase models) are MCS Accredited.

If you (or your installer) are not MCS Accredited, don't worry - Kensa is one of very few organisations that can cover this on their behalf, provided they will provide us with the required evidence.

This means that Kensa can arrange for you to receive an MCS Certificate for your project - it's this certificate that is the key to claiming RHI payments.

What's MIS 3005?

MIS stands for MCS Installer Standards. 3005 is just the issue number.

These are the standards that all MCS Accredited installers have to abide by.

They tell us how to quote, how to size, and how to install heat pumps. The standards exist to ensure consistency and quality.

If we are covering an installation under our MCS Umbrella Scheme, we have to be satisfied that the installation complies with everything laid out in MIS 3005.

This is why we ask for evidence in the form of photographs and calculations, and signed documents from installers to assure us that all guidelines are adhered to.

MIS 3005 Installer standards

MCS heat pump calculator (useful tool for doing heat losses) - can be found at the above link, under "heat Pump Reference Materials"

Why bother?

If we (or any other installer) don't stick to MCS rules, or MIS 3005 guidelines, we can be penalised.  At the worst, our MCS Accreditation could be removed which would be exceptionally bad for business!

The rules are there to make sure that customers are given correct, clear information. No one wants to see the industry suffer damage to its reputation as a result of customers being misinformed.

Another part of MCS is to make sure that no one manufacturer or installer has an advantage over any other by not offering accurate information, or by not telling the truth about a product or service.

Everything can appear very tightly controlled but there are good reasons for it!

Requirements for MCS Umbrella Scheme

List of Requirements

In order for Kensa to cover the MCS Accreditation on your project, we'll need the following information.  This checklist is also downloadable from the course portal.

Signed end user contract

Signed installation contract

These are zero-value contracts that assign the responsibility for the installation to Kensa, and oblige the householder and installer to provide accurate information.

Signed risk assessments for the type of work completed

These are provided to ensure your contractors comply with Health and Safety regulations. The signature tells us that they have read and understood any applicable risks.

A valid copy of your plumber's G3 certificate or card

This document proves that your plumber is qualified to install unvented hot water cylinders. Please ensure it is within date. If you are not installing one, you don’t need to produce this.

A photo of the label on the new cylinder, showing that it has been completed by the plumber/installer

Unvented hot water regulations ask that the fitter’s details are left on the cylinder. This proves to us that it’s been done.

A copy of the installer's Part P certificate – or the electrician’s completion certificate for the property

“Part P” is part of the electrical regulations that allows trained professionals to do basic electrical work. If you are using a fully qualified electrician, ask for a copy of his qualification.

Confirmation that your DNO has been notified

The DNO is the electrical grid provider. They must be told if you are fitting a heat pump, in case the current draw is more than the supply can manage. Normally an email from your DNO is sufficient evidence.

Room by room heat losses

We will need full heat losses (compliant to BS EN 12831). Kensa can provide this service for you.

Heat emitter details

We will need details of the underfloor heating and/or radiators you are fitting. A system schematic is helpful. A drawing of the UFH system is required, as is a radiator schedule showing types, sizes and outputs of rads fitted.

Heat emitter details

If you have additional heaters such as electric towel rails, please tell us the outputs and where they are fitted.

Heat emitter details

Please tell us if your UFH system is screeded, plated, or both.


Heat emitter details

Please tell us the floor coverings in each room where UFH is fitted – choose from tile, wood or carpet.


We require a photograph showing the system as “meter-ready” (i.e. that there is a space to fit a heat meter if one is needed).


If your system is “bivalent” (more than one source of heat) we will need details of the heat metering system you have fitted. We will need details of how your system is configured. We will need the calibration certificate for your heat meter(s).

Ground arrays sketch

We require a sketch showing where the ground arrays have been located. A marked-up site plan is ideal.

Antifreeze samples

Please return two samples of antifreeze in the bottles provided. Take your samples around an hour apart to ensure the mixture has had time to circulate.

Pressure test certificate

If you are using boreholes, please ask your driller to provide evidence that the probes have been pressure tested.

Overall cost (including materials and labour)

This doesn’t have to be exact– it is for the insurance-backed guarantee that you get as part of being MCS Accredited.

Controls – confirmation that you have enabled weather compensation on the unit, and a description of what controls you are using on the system

In order for us to issue an Energy Efficiency label for the whole system, we need to know what controls are being used. Heat pump standards suggest that weather comp should be used, but it is not mandatory.


Domestic RHI vs Non-Domestic RHI


The RHI stands for Renewable Heat Incentive.

This is a Government scheme to reward people who invest in renewable energy.

The idea is to help cut CO2 emissions and encourage uptake of renewables.

The RHI tariffs for Ground Source Heat Pumps are  generous compared to other renewable technologies. This is because ground source is generally more expensive to buy and install, so the higher payments reflect the higher capital expenditure.

As a rule, we have found that the returns from the RHI over its duration will cover the cost of the heat pump, so the householder will benefit from lower bills - for the duration of the RHI and after it's finished.

There are two types of RHI funding for ground (and water) source heat pumps:

  • Domestic
  • Non Domestic

Domestic RHI covers systems installed to heat single dwellings.

The application to the RHI itself is done by the householder.

Domestic RHI will not cover heat generated to heat a swimming pool or spa (space heating is fine - just not the pool water itself).

Multiple properties can be eligible for either domestic or non domestic RHI. Just because the ground array may be shared, doesn't mean that non-domestic RHI has to be claimed. It may be easier for the two clients to claim domestic RHI individually.


Non Domestic

Non  domestic RHI covers basically installations that are not single dwellings!

Some examples of projects where non-domestic RHI has been claimed:

  • A heat pump at a garden centre, heating the retail floor and providing hot water 
  • A heat pump providing space heating to three offices in the same block
  • A heat pump as part of a bivalent system, providing space heating and hot water to a community hall
  • Two heat pumps - one heating a domestic dwelling and another heating a holiday let belonging to the same homeowners, using a shared or "common" ground array
  • Heat pumps in social housing - each house with its own heat pump, and the ground arrays shared by at least two houses.

Heat pumps on common ground arrays are referred to as "micro-district heating systems" - they are district heating but generally on a small scale. They are considered district heating because they use shared "plant" - i.e. the ground array. This has been confirmed in writing by OFGEM.

Other eligible uses of heat include commercial or industrial processes that might require heating.  A swimming pool may be eligible under non-domestic RHI, but only if it was considered a commercial property - not at a domestic dwelling.

In order to claim non-domestic RHI, your installation will need metering.




At a glance

Requirements to claim RHI

Claiming Domestic RHI

Claims for domestic RHI are normally made by the owner of the system (generally the householder).

Most simple systems do not need metering, but if the system is bi-valent or only heats part of the property, then you will require heat meter(s) and power meter(s).

You will need a current EPC (energy performance certificate), your MCS certificate, your bank details, and if you do require metering, you will need to complete a metering questionnaire.

Some useful links:

Before you apply

Application form help sheet

Metering guidance

Claiming Non-Domestic RHI

The process for claiming non-domestic RHI is a little more convoluted than for domestic.

We normally advise that you allow Kensa to handle it for you, because there are a lot of questions in the application and many of them are quite technical.

You will still need an MCS certificate (or more than one, if there are multiple units) for the project. You will need to create an account on OFGEM's online application system (known as E-Serve).

You will also need to decide what name the application is made under (this can be a business). You will have to nominate one person as the Authorised Signatory for the application, and that person will have to provide personal information in order to undergo identity checks.

You will have to provide bank details on headed paper for the payments, and the name on this bank account must match the name on the application. 

The installation will need to have heat meter(s) and power meter(s) fitted. You will have to take photographs of everything, including the meters (showing their serial numbers and readings)

It is possible to claim non-domestic RHI in phases - to start a claim, and as additional heat pumps come on-line as the project progresses, to then add to the claim.

However the first part of the claim must be eligible for non-domestic RHI itself - so for example, you cannot build a house, fit a heat pump in it, and then hope to claim non-domestic RHI on the premise that you are planning to convert some outbuildings to holiday lets later on.


Some useful links:

How to apply for Non Domestic RHI

Easy guide to applying

Guide to using the online application system

Metering guidance


What is SCOP?


Why air source has it easy

Further reading:

Fact sheet

ERP and Eco-labelling

What is ERP?

ERP stands for Energy Related Products.

As at September 2015 all heat pumps (and other energy producing appliances) must have a label showing their energy performance, both as an indicidual product, and as part of a system.

That label is an "ERP label".

ERP regulations have been created to help lower carbon emissions and increase the proportion of heat generated from renewables.

It means that manufacturers have to design eco-friendly products, and installers and manufacturers of those products have to label them clearly.

The label itself will show a rating from G (poor) to A++ (very good). This is a lot like the efficiency labelling you will see on other domestic appliances.

There are 2 kinds of label - one for the individual product, and one for the whole system.

If you are keeping any bit of the old system (e.g. controls) then you don't need to create a system label.

If everything is new, then you must.

The hot water cylinder does not need a product label unless it is a solar cylinder (twin coil).

You can create the labels yourself on line - there is a tool on the Kensa website.

All of Kensa's heat pumps are A+.

Further reading:

ERP support at Kensa's website

Eco labelling - the installer's responsibilities

As an installer, it is your responsibility to put a product label on the heat pump, and if applicable, create a package label for the system.

We will gladly supply the product label, and you can use the online tool to create the package label. You will need to know what class of controls you are fitting to the system.

ERP label creation tool


Tick what you think is needed

  • For the heat pump SCOP
  • For pictures of the meter(s) installed
  • For the details of the staff that use the heat pumps
  • For a calculation proving any heat lost from pipework in unheated areas
  • Heat losses
  • Details of the ground array
  • The price paid for all works
If you are claiming non-domestic RHI, what do you think you'll be asked as part of the application?

Match the definition...

  • ERP is:
    A new rule that means heat pumps have to be labelled to show their efficieny
  • MIS 3005 is:
    The installer standards that MCS Approved installers must comply by
  • MCS is:
    A Governemt scheme overseeing all renewable products
  • SCOP can..
    Show the efficiency of a heat pump at a set flow temperature
  • COP shows
    a very simple way of illustrating a heat pump's efficiency