Electrics and gas
Refrigerant lines of a split system are unlagged across the garden. Has the refrigerant charge been weighed?
No. The refrigerant charge has not been weighed. Unlagged pipes across the garden are a visual defect: the lines between the indoor and outdoor parts of a split system are bare. Missing lagging can let those pipes gain or lose heat and can leave the copper exposed. It does not say how much refrigerant is in the circuit. This visit did not fit gauges and did not weigh a charge. The survey records bare lines. It has not tested the heat pump and has not decided the charge is correct.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What is the fuller explanation?
A split system moves refrigerant between an outdoor unit and an indoor coil. The pipe run is normally insulated so the lines behave as intended and so the copper is protected. Where lagging is missing, the surveyor can see that. The amount of refrigerant is invisible. Checking it needs equipment and a procedure a home survey does not carry out. An oil stain or a bare pipe may each matter, and neither is a weighed charge. Do not read the report as a refrigeration test.
Ask the seller for any commissioning sheet that may record a charge, and do not treat that sheet as verified by this survey. The Boiler Upgrade Scheme, in England and Wales, is a grant route and does not weigh refrigerant on a later inspection. Approved Document L guides building work. It is not a certificate this visit issues. If the bare lines and the charge both concern you, a heat-pump engineer can inspect. Tell a lender the lagging was missing and the charge was not weighed.
What should you ask your surveyor?
- How much of the run is bare, and is it one line or both?
- Are there oil stains or physical damage, or only missing insulation?
- Is there a commissioning sheet stating a charge the survey has not checked?
What are the typical next steps?
- Record the missing lagging as seen, and the charge as not weighed.
- Ask the seller for the commissioning record without calling it verified.
- Instruct a heat-pump engineer if the refrigerant circuit needs a real test.
Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.
Also asked about this
Does missing lagging prove the refrigerant has leaked away?
No. Bare pipes are an insulation defect. A leak is a different fault and was not tested here. The charge was not weighed, so the survey cannot say the system is full or short. An oil stain, if one is noted, is still not a weighed loss. An engineer would have to test the circuit. This visit did not.
Can new lagging be fitted and the charge ignored?
New lagging would cover the bare copper the survey could see. It would not tell you whether the charge is right. The survey has not treated insulation as a refrigeration test. Deal with the pipe covering if an engineer agrees, and keep the unweighed charge as a separate point that is still open.