Swapping an R410A cassette means thinking about the whole system: outdoor unit, indoor unit, pipework, oil, controls, ceiling void and drain. A modern cassette charged with a different refrigerant is not a drop-in for an R410A outdoor unit. Pressures, oils and components differ, and only the new manufacturer's rules can say whether any existing copper may stay. The old charge has to be recovered by a certified company. Budget a replacement system, not a new fascia.
A new fascia on an old R410A outdoor unit
The cassette panel is what customers see. The system is the matched outdoor unit, the refrigerant the pair was built for, the pipe sizes that pair allows, and the controller that speaks to both. R410A equipment is leaving the catalogue as current ranges move on. Buying a new indoor panel and hoping it will run on the old outdoor unit mixes two designs.
Matched indoor, outdoor and refrigerant
Some manufacturers publish a route to reuse existing pipework after their own cleaning and sizing checks. That route is specific. It is not a general permission to put any new cassette on any old pair of pipes. The survey writes yes or no against the manual, in words. Match indoor, outdoor and refrigerant as one system.
Grid size, a dead pump and today's trade
Grid size may have changed between cassette generations. A new panel that does not match the tile, or a unit that needs more void height, is a builder's problem.
- The drain may have been a pump that is now dead.
- The electrical supply may have been adequate for the old maximum current and tight for the new one.
- A competent electrician confirms the supply. This page will not specify breakers.
- A cafe that became a hairdresser, or a shop that now leaves the door open, is not the load the old cassette was bought for.
The new charge has its own leak-check band
Recovery of the R410A, any decision about the new charge, and commissioning of the new circuit belong to an F-gas certified company. GOV.UK publishes that certification. There is no house procedure here for converting gas, flushing oil or weighing a charge. The old R410A is recovered and sent on a lawful waste route. Venting is illegal. Ask for the recovery record with the new commissioning sheet. Leak-check duties on the new system depend on the carbon-dioxide equivalent of whatever charge the new equipment holds. Ask for that figure at handover and compare it with current GOV.UK guidance. Do not copy the old R410A interval onto a new gas.
A mid-thousands replacement, not a fascia price
As a 2026 illustration, replacing a single shop cassette and its outdoor unit is commonly a mid-thousands-of-pounds conversation including VAT once recovery, a new pair, making good the ceiling and recommissioning are included. A fascia-only price that ignores the outdoor unit is not a comparable quote. Access out of hours, asbestos in old grids, and a condenser that must move to satisfy planning or a lease will lift it. The Planning Portal heat-pump page is a domestic starting point, not a consent for moving a shop condenser. Energy Saving Trust's air-to-air pages describe the class of equipment. They do not authorise a drop-in. If the wider building system is large enough, the GOV.UK air conditioning inspection duty may still apply after the swap. Tell the operator so the log stays continuous.
When a top-up of a different gas is the wrong job
That approach is wrong when someone offers a top-up of a different refrigerant into the old circuit. Refuse it. It is also wrong to put a new R32 cassette on an old R410A outdoor unit as a drop-in. They are different systems. Only a manufacturer-approved matched combination is acceptable, and most replacements are a new indoor and a new outdoor. The survey has to say so in writing. Old pipes stay in the ceiling only if the new manual allows that diameter and condition and any required preparation is done by the certified installer. It is not automatic. If the manual says no, budget new pipework. Ceiling grid, panel size and drain still have to fit.
Core buying guides
Start with these high-intent guides, then dig into the rest of the library.
Related guides
Sources and further reading
How this guide was prepared
This guide was written by the Local AC Installers Editorial Team. We compare official guidance, legislation and established consumer information, separate general information from project-specific advice, and show publication dates and sources. We do not accept installer accreditation claims at face value.