Refrigerant Leak Response and Repair Authorization

Purpose

This standing instruction guarantees that a system losing refrigerant leaves the visit with three things that did not exist when the tech pulled up: a located leak backed by physical evidence, an accounting of how much refrigerant went in and where it came from, and a written repair-or-replace position the customer said yes or no to on a dated form.

Without it a shop drifts into the top-off habit. A tech adds two pounds, the ticket closes as "low on charge," and the same system is on the board every spring for six years while the customer pays repeatedly for refrigerant that is now in the atmosphere. A leak is a repair with an authorization decision attached, not a consumable.

Safety actions that come before any panel opens

Do these in order, on every leak call, before diagnosis.

• If refrigerant is audibly escaping or you see fog at the equipment, get people out and prop the door open. Common refrigerants are heavier than air and displace oxygen at floor level, which is why a mechanical room or crawlspace kills people an open yard would not. Do not enter a below-grade space with a suspected large release until it is mechanically ventilated and a personal oxygen monitor reads normal.
• On an A2L system (R-454B, R-32 and the rest of the mildly flammable group), kill ignition sources before you sweep. No torch lit, no contactor cycled by hand, no drop light plugged in inside the space. If the refrigerant label is missing, treat it as A2L until you identify what is in it.
• Liquid refrigerant freezes skin. Gauntlet gloves and sealed eye protection any time you crack a fitting, break a flare, or handle a hose that may hold liquid.
• Never braze, cut, or apply heat to a line that still holds refrigerant. HFC over an open flame breaks down into hydrogen fluoride and carbonyl fluoride, which injure the lower airway at concentrations you can tolerate on the first breath. Recover first, then flow dry nitrogen through the joint while you braze.

Scope

Covers split, packaged, heat pump and ductless equipment on any residential or light-commercial call where refrigerant loss is suspected, from arrival through the authorization decision.

Does not cover recovery mechanics, cylinder selection or cylinder handling, owned by the refrigerant recovery and cylinder management SOP. Does not cover changeout execution once replacement is authorized, owned by the system changeout day-of-install standard. Does not cover supermarket rack or industrial process refrigeration, where the thresholds and record-keeping duties are stricter.

Roles and handoffs

Procedure

1. Read the nameplate and the account history before you connect anything. Write down refrigerant type, factory charge, line-set adder if the install record has it, and every prior weighed-in amount with its date. Acceptance: a total system charge figure and at least the last charge event, or an explicit note that no history exists. Wrong looks like starting from gauges with no charge figure, which makes every later percentage meaningless. If the nameplate is unreadable, get the model decoded from the manufacturer's data rather than guessing. Keep hands clear of the fan section while reading a condenser nameplate; a unit under a call restarts without warning.

2. Record the system running as found, before you change anything. Suction and liquid pressures with their saturation temperatures, suction and liquid line temperatures at the service valves, return and supply air dry bulb, and compressor amps against nameplate RLA. Acceptance: all eight values plus outdoor ambient. Wrong looks like two pressures and nothing else, which cannot separate a leak from a restriction or a failed metering device. If the system will not stabilize, note why rather than inventing steady-state numbers.

3. Confirm the loss is real and put a rate on it. Compare weighed-in history against elapsed time and express it as a percentage of total charge per year. Acceptance: a numeric annual loss rate, or a documented standing pressure test where there is no history. Wrong looks like calling any low subcool a leak; a plugged filter drier, a hunting valve and low indoor airflow all read low on the low side. If the numbers point at a restriction, stop the leak search and diagnose the restriction, because charging on top of one makes the system worse.

4. Locate the leak with a method that leaves evidence. Bump-test the electronic detector on a known source before you sweep, work the joints, coil returns, Schrader cores and valve stems, then confirm every hit with bubble solution or a second instrument. Acceptance: a leak you can point at, photographed, with the confirming method named. Wrong looks like one detector alarm and no confirmation. Stop rule: if you cannot confirm a location, add no refrigerant and name no component - escalate to the standing nitrogen test in step 5 or quote a return visit with the coil opened up.

5. Where the sweep is inconclusive, pressurize with dry nitrogen and hold it against a temperature correction. Recover the remaining charge first, then pressurize through a regulator to the manufacturer's stated test pressure and never above the lowest-rated component in the circuit. Acceptance: pressure holding over at least one hour after you correct the reading for the ambient change, in absolute pressure and absolute temperature. Wrong looks like calling a pressure drop a leak when the sun went behind a cloud. Nitrogen is an asphyxiant and an unregulated cylinder bursts lines, so regulate every time, and never pressurize with oxygen or shop air, which forms an explosive mixture with refrigerant oil.

6. Classify the appliance against the leak repair rules before you write the position. Comfort cooling appliances holding 50 pounds or more fall under the leak repair provisions at 40 CFR Part 82 Subpart F, which trigger repair at a 10 percent annualized leak rate and require verification tests; the AIM Act refrigerant management rule at 40 CFR Part 84 extends leak repair and inspection duties to HFC appliances at a lower charge threshold, so confirm the threshold and compliance date for the appliance in front of you rather than assuming the 50 pound figure covers you. Acceptance: the rule set named on the record. At any size, knowingly venting is prohibited, so recovery is never optional.

7. Repair, then prove the repair before any refrigerant goes back in. Braze with dry nitrogen flowing, pressure test again, then evacuate. Acceptance: the vacuum holding under a closed-off decay test, not just touching a target number once. Wrong looks like a gauge reading deep because the core is still in and only the hose got evacuated. Use cadmium-free brazing alloy; cadmium-bearing silver alloys release cadmium oxide fume that produces delayed lung injury from a single afternoon, and a nuisance dust mask does nothing for it.

8. Weigh the charge in, run the system, and re-verify. Charge by weight to nameplate plus line-set adder, then run and confirm subcool and superheat land in the manufacturer's window. Acceptance: scale weight plus target readings met. Wrong looks like charging to a pressure chart on a system whose airflow was never checked. Book the follow-up verification before you leave the driveway; a repair nobody re-checks is one the customer discovers failed in July.

9. Present the repair-or-replace position in writing and record the decision. Give the located leak, the annual loss rate, the age and refrigerant type, and the recommendation with its reasoning. Acceptance: a signature, or a recorded verbal decline with a timestamp. Exception path: if the customer declines, the shop standard is one documented top-off with a signed acknowledgment that the leak is known and located, never a second on the same fault. If the leak was never located, no refrigerant is added at all and the ticket closes as diagnostic.

The record this produces

One leak record per event, attached to the equipment rather than the ticket, so the next tech opens the unit's own history instead of three years of unrelated notes:

• Refrigerant type, total system charge, and the source of that figure (nameplate, install record, decoded model)
• Leak location, confirming method, photograph
• Amount recovered and cylinder number, amount weighed in and cylinder number
• Annualized loss rate with the two dates it was computed between
• The rule set the appliance falls under, and any verification tests owed
• The written position, the decision, and who made it

Office reads it to invoice and book the follow-up. The next tech reads it to know whether this is a first event or a pattern. The manager reads loss rates across the book to find accounts where the shop is funding an old system.

Worked pass: 3-ton R-410A heat pump, second loss in two seasons

Nameplate factory charge 8 lb 4 oz, install record adds 1 lb 8 oz for the line set, so total charge is 9 lb 12 oz (9.75 lb). Prior visit 14 months ago weighed in 2 lb 6 oz (2.375 lb) with no leak located.

Step 3, loss rate: 2.375 lb over 14 months annualizes to 2.375 x 12 / 14 = 2.04 lb per year, which against 9.75 lb total is 20.9 percent per year. Real loss, well past any reasonable shop threshold.

Step 4 FAILS its acceptance condition. The detector bump-tests fine and alarms once near a service valve stem, but bubble solution shows nothing there on two attempts. No confirmed location. Stop rule taken: no refrigerant added, escalate to step 5 rather than charge and leave.

Step 5, standing test: remaining charge recovered, system pressurized with dry nitrogen to 300 psig at 82 F ambient. After 60 minutes the gauge reads 288 psig at 76 F.

• Correction, printed: start absolute 300 + 14.7 = 314.7 psia at 541.67 R. Expected at 535.67 R is 314.7 x 535.67 / 541.67 = 311.2 psia, which is 296.5 psig.
• Measured 288 psig is 302.7 psia. Unexplained loss is 296.5 - 288 = 8.5 psi in one hour. That is a leak, not the weather.

Coil compartment opened, detector alarms at a hairpin return on the indoor coil, confirmed with bubbles and photographed. Step 4's acceptance condition is met on the second pass.

Step 9: coil out of warranty, unit 11 years old on a refrigerant being phased down, repair cost a meaningful fraction of replacement. Position written both ways, customer declines the coil. Exception path taken: one documented top-off, signed acknowledgment naming the hairpin as the located leak, and an account note that no second top-off is authorized on this fault.

Checking the pass against the sections above: step 3 computed against the 9.75 lb total stated at the top, not the 8.25 lb nameplate figure. The appliance sits far below the Subpart F charge threshold, so the 10 percent trigger named in step 6 does not apply and the record says so rather than implying a federal repair duty that does not exist here. The venting prohibition does apply, which is why step 5 recovers before it pressurizes.

References

• 40 CFR Part 82 Subpart F, the Section 608 requirements, for the venting prohibition and the leak repair provisions above the charge threshold
• 40 CFR Part 84, the AIM Act refrigerant management rule, for the HFC leak repair and inspection duties and their compliance dates
• 29 CFR 1910.1027, the cadmium standard, for exposure control when a silver brazing alloy is not cadmium-free
• Manufacturer's installation and service instructions for nameplate charge, line-set adder, and permitted nitrogen test pressure
• See related: the refrigerant recovery and cylinder management SOP, and the system changeout day-of-install standard