Home Heat Pump Guide

Heat Pump Decommissioning: Removing an Old System

Whether your heat pump has reached end of life, you are upgrading to a newer model, or circumstances mean the system is no longer needed, removing a heat pump is not as simple as unplugging it and carrying it away. There are legal requirements around refrigerant handling, electrical disconnection procedures, and proper disposal of components.

This guide covers the full decommissioning process, what it costs, who can legally do the work, and the situations where heat pump removal becomes necessary.

When Do You Need to Remove a Heat Pump?

There are several scenarios where heat pump decommissioning becomes necessary:

  • End of life replacement: Your heat pump is 15 to 20 years old and you are replacing it with a new unit. The old system must be properly decommissioned before the new one is installed.
  • System failure beyond economic repair: A major component has failed and the repair cost exceeds the value of the system.
  • Property renovation: Major building work requires the removal of the outdoor unit, pipework, or indoor components.
  • Change of heating system: In rare cases, a homeowner may switch to a different heating technology, though this is uncommon given the direction of UK energy policy.
  • Incorrectly installed system: If an original installation was poorly designed, undersized, or installed by an unqualified person, complete removal and replacement may be the only practical solution.
  • Property demolition: The heat pump must be properly decommissioned before any demolition work.

Legal Requirements for Heat Pump Removal

The most important legal requirement relates to refrigerant. Under UK F-gas regulations, it is illegal to vent refrigerant into the atmosphere. All refrigerant must be recovered by a certified engineer using specialist recovery equipment.

Refrigerant Recovery

Before any physical removal work begins, every gram of refrigerant must be extracted from the system. This involves:

  • Connecting recovery equipment to the heat pump's service ports
  • Running the recovery machine to extract all refrigerant into a certified recovery cylinder
  • Verifying that the system is fully evacuated using a vacuum gauge
  • Documenting the type and quantity of refrigerant recovered
  • Ensuring the recovered refrigerant is either sent for recycling, reclamation, or destruction at an approved facility

The engineer must keep records of all refrigerant recovered, and these records must be available for inspection. Penalties for illegally venting refrigerant are severe — fines can reach tens of thousands of pounds.

Electrical Disconnection

The heat pump must be electrically isolated before removal. This involves:

  • Switching off and locking out the dedicated circuit breaker in the consumer unit
  • Disconnecting the electrical supply at the outdoor unit's isolator switch
  • Removing or making safe any dedicated wiring runs
  • If the dedicated circuit is no longer needed, the circuit breaker should be removed from the consumer unit by a qualified electrician

Waste Disposal

Heat pumps contain metals, plastics, electronic components, and refrigerant oil that must be disposed of responsibly. The outdoor unit is classed as Waste Electrical and Electronic Equipment (WEEE) under UK regulations. Your installer or removal contractor should ensure the unit is taken to an approved recycling facility rather than sent to landfill.

The Decommissioning Process Step by Step

Step 1: Assessment and Planning

A qualified engineer assesses the system, confirms the refrigerant type and estimated charge, checks the electrical setup, and plans the removal sequence. If the system is being replaced, this assessment is usually part of the new system survey.

Step 2: System Shutdown

The heat pump is shut down through its normal controls. The engineer may run the system briefly in a specific mode to pump refrigerant into one section of the circuit, making recovery more efficient.

Step 3: Refrigerant Recovery

Using certified recovery equipment, the engineer extracts all refrigerant from the system. This typically takes 30 minutes to an hour for a domestic heat pump, depending on the system size and refrigerant type.

Step 4: Electrical Disconnection

The electrical supply is isolated and disconnected. Cables are either removed or made safe for reuse with the new system.

Step 5: Pipework Disconnection

Refrigerant pipes, water pipes, and any other connections between the outdoor unit and the indoor components are disconnected. If the system is being replaced with a similar model, some pipework may be reused.

Step 6: Physical Removal of the Outdoor Unit

The outdoor unit is unbolted from its base and removed. Domestic air source heat pumps typically weigh between 60 and 120 kilograms, so this usually requires two people. For larger units or difficult access situations, mechanical lifting equipment may be needed.

Step 7: Indoor Component Removal (If Required)

If the entire system is being removed rather than replaced, indoor components are also taken out:

  • Hot water cylinder (if dedicated to the heat pump)
  • Buffer tank (if fitted)
  • Controls and wiring
  • Any dedicated pipework that will not be reused

If you are replacing the heat pump with a new one, many indoor components may be retained. The new installer will advise on what can be reused and what needs replacing.

Step 8: Making Good

After removal, the area needs tidying up:

  • Pipe penetrations through walls should be sealed
  • The outdoor base or mounting brackets may be removed or left in place for a replacement unit
  • Any damage to walls, floors, or decorations from the removal should be repaired

Step 9: Documentation

The engineer provides documentation including:

  • Refrigerant recovery certificate showing type and quantity recovered
  • Waste transfer note for the disposed equipment
  • Confirmation that the system has been safely decommissioned

How Much Does Heat Pump Removal Cost?

The cost of decommissioning and removing a heat pump depends on the scope of work:

  • Refrigerant recovery only: £150 to £300 — if you just need the refrigerant safely removed, for example before a different contractor removes the physical equipment
  • Full outdoor unit removal (as part of a replacement): £300 to £600 — most replacement installers include decommissioning of the old unit in their overall quote
  • Complete system removal (outdoor unit, cylinder, pipework, making good): £500 to £1,200 — a full strip-out where no replacement is being installed

If the removal is part of a new heat pump installation, most installers absorb the decommissioning cost into their overall installation price. Always confirm this when getting quotes — some may list it as a separate line item.

Ground Source Heat Pump Decommissioning

Removing a ground source heat pump follows the same process for the heat pump unit itself. However, the ground loop — the network of pipes buried in your garden — raises additional questions:

  • The ground loop is usually left in place. It is buried at depth (typically 1.2 to 1.8 metres for horizontal loops, or in boreholes for vertical systems) and removing it would involve extensive excavation. The antifreeze solution can be flushed and the loop left dormant.
  • A new ground source heat pump can connect to the existing loop if it is in good condition and correctly sized for the new unit.
  • Borehole loops are essentially permanent fixtures. They can be abandoned in place with no environmental impact, or reused for a replacement system.

Recycling and Scrap Value

Heat pump outdoor units contain copper, aluminium, steel, and electronic components that have scrap value. While you are unlikely to profit from scrapping an old heat pump, the metal content can offset disposal costs. A reputable removal contractor will ensure the unit goes to an approved WEEE recycling facility where materials are recovered properly.

Never allow an unqualified person to remove a heat pump with the intention of scrapping it. The refrigerant must be recovered first, and this requires certified equipment and qualified personnel.

Can I Remove a Heat Pump Myself?

In short: no, not fully. You are legally prohibited from handling refrigerant without F-gas certification. Electrical disconnection should be carried out by a qualified electrician. The physical removal of the outdoor unit is heavy and potentially dangerous if not done properly.

What you can do yourself:

  • Clear the area around the unit to give the removal team easy access
  • Remove any fencing, trellising, or decorative screening you have built around the unit
  • Ensure there is a clear path from the unit to the access point for the removal vehicle

Frequently Asked Questions

How long does heat pump decommissioning take?

For a straightforward domestic air source heat pump, allow half a day. Refrigerant recovery takes 30 to 60 minutes, electrical disconnection 30 minutes, and physical removal another hour or so. If indoor components are also being removed, allow a full day.

Do I need planning permission to remove a heat pump?

No. You do not need planning permission to remove a heat pump. However, if you installed the system under permitted development rights and received any conditions, check whether there are any requirements related to removal or replacement.

Can the old base be used for a new heat pump?

Usually yes. Concrete bases and ground-level pads can typically be reused for a replacement unit, although the new unit may have different mounting dimensions. Your installer will confirm during the survey whether the existing base is suitable.

What happens to recovered refrigerant?

Recovered refrigerant is sent to a specialist facility where it is either reclaimed (cleaned and re-certified for use), recycled (processed for re-use in the same type of equipment), or destroyed (for refrigerant that cannot be reclaimed). All routes are tightly regulated under UK F-gas and waste regulations.

Will removing a heat pump affect my EPC rating?

Yes. If you remove a heat pump and replace it with a less efficient heating system (or no heating system at all), your EPC rating will drop. If you are replacing it with a newer, more efficient heat pump, your rating should remain the same or improve.

Can I remove just the outdoor unit and keep the indoor components?

You can remove the outdoor unit while keeping the hot water cylinder and pipework in place if they will be reused with a replacement system. If no replacement is planned, keeping orphaned components serves no purpose and they should be removed to free up space.