R-Pro › Field cases › Air conditioning
System AC Drain Pump Cleaning / Replacement — Ceiling Leak Emergency
Likely causes
Step 1 — Emergency action + identify leak point
Check: **Immediate action**: tell user to turn system OFF + breaker OFF. Catch drips with container. Ceiling-recessed system AC = no gravity drain, uses forced pump to lift water. **Locate leak**: ① Listen for pump operation sound (normal = soft hum). No sound = pump coil/float switch fault. ② Pump runs but no discharge = impeller clogged or drain hose blocked. ③ Discoloration/mold on ceiling = leak duration estimate (1–3+ months).
What to do: **Clean impeller/float** (resolves 60% of cases): remove pump → clear impeller of debris/slime → disassemble and clean float switch → reassemble → test (pour 1 L water into pan → pump runs + drains in 90 sec). **Replace pump** (coil open): same-spec new unit (12V/24V, flow L/min per manual). Residential KRW 50–150k. **Drain hose clog**: wet-vac from discharge end. Finish with **antimicrobial spray** (vinegar 1:16; bleach risks copper/aluminum corrosion). **Pre-season service** prevents 80% of leaks.
**Field trick**: ceiling leak = #2 reported issue (after filter). Emergency dispatch required — upstairs/downstairs disputes. **Filter cleaning every 2 weeks** + season-start pump cleaning prevents 80% of leaks. Educate user. **Pump life** = 3–5 years (7+ years with regular cleaning). Ceiling damage from leak = separate quote (paint/replace).
All 565 cases work offline in R-Pro, with error codes for 62 brands and P-T data for 108 refrigerants.
Open R-Pro →