The MCS heat pump Standard MIS 3005 was split into two separate Standards covering design and installation, with both becoming mandatory on 1 April 20221. The certification body MCS announced the change in an installer briefing published on 29 March 2022, three days before the new Standards took effect1.
The two documents are MIS 3005-D for heat pump design and MIS 3005-I for heat pump installation1. They were published on the MCS website on 1 December 2021 and became mandatory on 1 April 2022, following the closure of the Domestic Renewable Heat Incentive1. MCS said the split was intended to improve access to the MCS Scheme, reflecting two distinct skill sets in the sector, with system design separate from installation1.
"This split is intended to improve access to the MCS Scheme, reflecting two distinct skill sets that exist within the heat pump sector, with system design separate from installation."
Under the arrangement, contractors already certified to the previous standard, MIS 3005 issue 5.0, were automatically granted certification to both new Standards on 1 April 20221. MCS described this as "grandfather rights", with existing certified contractors continuing to be certified until their next surveillance visit, at which point they will be asked to confirm to their certification body whether they wish to be certified for design only, installation only, or both1. Compliance certificates are no longer required, and the MCS Installation Database (MID) is being updated to support the split1.
| Item | Detail |
|---|---|
| Design Standard | MIS 3005-D |
| Installation Standard | MIS 3005-I |
| Published | 1 December 2021 |
| Mandatory from | 1 April 2022 |
| Existing certified contractors | Automatically certified to both new Standards |
The change allows contractors who wish to focus on installation only to work with an independent designer, and allows a designer to support certified installers1. MCS has not reported how many contractors have since chosen design only, installation only or both.
Why it matters for households
The Heat Pump Standards, Testing and Certification that govern MCS-certified work now separate the party responsible for designing a system from the party responsible for installing it. For a household, that means the sizing, heat loss calculation and emitter specification can sit with a designer while the physical installation is carried out by a different certified contractor1. A poorly sized system tends to run at higher flow temperatures and use more electricity than necessary, so the design stage carries direct weight on running costs and on how much of a home's heat demand the property can meet from its own supply.
The split also widens the pool of contractors able to take on installation work, which MCS said was intended to accommodate an increase in contractors wishing to install heat pumps1. Households weighing a heat pump as a route to household energy independence are therefore dealing with a certification landscape where design and installation credentials are held separately, and where the two roles may not sit with the same firm. The MCS Installation Standards for other technologies, including MIS 3001 and MIS 3002, were not part of this change1.
What happens next
Certified contractors will be asked at their next surveillance assessment to confirm to their certification body whether they wish to hold design certification, installation certification or both1. MCS has not reported a date by which all contractors must have made that choice.
Sources1 cited
- Installer Briefing: Changes to the Heat Pump Standard - MIS 3005 - MCS, mcscertified.com