Before you start

• •Dispatch slip with customer address, complaint, and contact number
• •Fully stocked service truck (refrigerant, capacitors, contactors, filters)
• •Digital camera or phone for photo documentation
• •Tablet or clipboard with service agreement form

The procedure

Step-by-step, in order. Each step has the action and the reason it matters.

1. 1

   Call ahead 20-30 minutes before arrival

   Call the customer when 20-30 minutes out. Confirm they are home, confirm the complaint hasn't changed, and ask if pets need to be secured. No-call arrivals lead to locked gates, no-shows, and wasted drive time.

2. 2

   Photo-document the equipment before touching it

   Photograph the unit nameplate (model + serial), refrigerant line set, disconnect box, and any visible pre-existing damage before work begins. Date-stamp photos. These photos protect you from claims that damage was caused by your tech.

3. 3

   Read the nameplate — confirm refrigerant type and tonnage

   Model number decodes tonnage (24 = 2 ton, 36 = 3 ton, 48 = 4 ton in most cases). Confirm refrigerant type (R-22 vs R-410A vs R-32) before touching refrigerant circuit. Wrong refrigerant charges destroy compressors.

4. 4

   Check electrical first — measure supply voltage at disconnect

   Clamp meter at the disconnect. Nominal 240V ±10% is acceptable (216-264V). Low voltage (under 210V) causes compressor overheating and must be documented and escalated to the utility — it is not a warranty issue the tech can fix.

5. 5

   Check capacitor readings

   Discharge capacitor fully before probing. Compare measured μF to nameplate rating — capacitor is failing if reading is more than 10% below nameplate. A weak capacitor is the #1 missed service item. Replace at first visit if under spec; do not 'monitor it.'

6. 6

   Check refrigerant charge with manifold gauges

   Connect gauges and let pressures stabilize for 3 minutes before recording. Target superheat/subcooling per OEM spec — not generic rules. Document: suction pressure, discharge pressure, calculated superheat/subcooling, outdoor ambient temp.

7. 7

   Check filter and static pressure

   Pull the filter. A dirty filter is the most common cause of AC complaints. Replace if past recommended life (1 inch = 30 days, 4 inch = 90 days, 5 inch = 6-12 months). Measure static pressure if airflow complaint — over 0.5" WC indicates blockage.

8. 8

   Document all findings on the service ticket — quote before you repair

   List every finding on the ticket. Price each repair. Get verbal and written authorization before proceeding. Do not perform unrequested work on a first visit even if you notice it — quote it, let the customer approve it.

9. 9

   Complete work, verify operation, document outcome

   After repair, run the system through a full cycle (at least 15 minutes). Confirm supply temp drop of at least 16-20°F vs return. Document final readings: suction pressure, discharge pressure, supply temp, return temp.

10. 10

    Leave a completed maintenance sticker on the unit

    Sticker goes on the unit — not the inside of a file folder. Include: tech name, date, filter size, next recommended service date, your company phone number. This sticker generates repeat calls.

Verify when done

• ☐Nameplate photo taken before work starts
• ☐Refrigerant type confirmed before touching circuit
• ☐Capacitor reading documented on ticket
• ☐Authorization obtained before any repair over $200
• ☐Final system run 15+ minutes documented
• ☐Maintenance sticker applied

Common mistakes

• ✕Connecting gauges without confirming refrigerant type first
• ✕Replacing capacitor without checking if it is actually under spec
• ✕Performing un-quoted work without written authorization
• ✕Leaving without a maintenance sticker on the unit

Trainer notes

The authorization-before-repair step is non-negotiable on new customers. Experienced techs skip it because they assume approval. New customer = no prior relationship = document everything.

Common questions