What we do

About the DIY install support package

Air conditioner and heat pump installation is expensive, but a good DIY-er can do most of it themselves and save hundreds or even thousands of pounds.

For safety and environmental reasons, only a qualified professional can legally do the F-gas related parts of an installation - and that’s where Checkmark can help.

Checkmark offers a fixed price package to help you legally and responsibly complete the DIY installation of an air conditioner / heat pump you have purchased. It saves you money because you don’t have to buy specialist tools and equipment. It also gives you peace of mind, because you know your unit has been rigorously tested and is legally installed.

Fixed price package

A typical visit to connect, test, commission and certify your DIY install takes between half and a full day and is priced at £395.

This is based on the ‘What is included’ and ‘What is not included’ sections below. It is ideal for those looking to put a ‘mini-split’ air-con / heat pump unit in a home or garden office, workshop or other space.

A pre-visit video call to review the install, confirm the install work done so far, answer any questions and arrange the visit.

This is useful to ensure everything is ready for commissioning.

Flaring of the copper pipe ends, and connections to the outdoor and indoor units.

The quality of the flare is crucial, especially for refrigerants like R32 that operate at a high pressure.

This involves pressurising the lines and indoor unit with Oxygen Free Nitrogen and conducting a leak test (both a timed and joint bubble test).

A pressure test is more effective than a vacuum leak test because it is testing for leaks at system pressure, rather than under a vacuum which tends to ‘pull’ small leaks closed.

This involves connecting a vacuum pump to the system and removing air/nitrogen down to at least the vacuum specified in the system manual. A vacuum hold test will be performed and any issues investigated.

When all tests are good, the pre-charged refrigerant will be released from the outdoor unit into the vacuumed pipes and indoor unit.

The system will then be checked to ensure it is operating to specification.

System temperatures and pressures are checked against manufacturer data and recorded in a commissioning log.

This forms the first part of the service record.

What is not included

The fixed price package is designed to cover most ‘mini-split’ air-con / heat pump DIY requirements.

The package is based on you doing a good physical installation of the indoor and outdoor units, electrics, condensate pipework, and positioning, but not connecting, the refrigerant pipework. The ‘Info’ section of the web-site has lots of useful information on planning your installation.

There may be extra charges if:

1. The install is outside the M25 or more than 20 miles from Bromley, Kent.
2. The unit rated as is 5kW or larger and/or has more than one indoor unit (see below).
3. The refrigerant pipe lengths are longer or shorter than the ‘pre-charge’ lengths that the unit allows in its documentation (often minimum 3m or maximum 15m per line).
4. If refrigerant pipes need lengthening or brazing (pipe runs are typically available up to 30m so this would be unusual)
5. If condensate pumps need to be installed.
6. The install is at a commercial premise.

The initial and pre-visit calls are designed to identify all of the above, meaning unexpected additional costs are avoided. If you have any questions, or are considering installing larger or multiple units, then please don’t hesitate to contact us.