Inspection 822ve6yu · 1617 Wichita St, Houston, TX 77004 · Draft · inspection incomplete
Carrier Performance™ 17 · Model 24ACB760A310 · Serial 4015E07086 · 5.0 tons · 2-stage · R-410A · 12.7 lbs · Factory SC 14°F · MCA 37.3 A · MOCP 60 A · LRA 152.9 A
Verify unit model (24ACB760A310) and manufacture date (September 2015). The source report lists an approximate age of 10–11 years and a 10-year factory warranty; verify the actual age and warranty coverage. Note overall corrosion and fin fatigue.
Inspect the WeatherArmor™ louvered cabinet for hail impact. Confirm the report’s reference clearances: 24 inches at service sides and 48 inches at the top discharge. Check pad level and verify applicable manufacturer requirements.
Force the thermostat to Stage 1 (Y1, approximately 70% / 3.5 tons), then Stage 2 (Y2, 100% / 5.0 tons). Verify the compressor’s internal unloader activates without metallic sticking or chatter.
The report specifies a 1-1/8-inch suction line for 5 tons and an expanded adapter at the 7/8-inch service valve; verify sizing against manufacturer guidance. Inspect vapor line insulation. Verify the crankcase heater is energized and warm to protect the 12.7 lb charge against flooded starts.
Measure running amperage in Stage 2 and compare with the nameplate RLA of 28.8 A. Note the locked-rotor rating of 152.9 A.
Test capacitance under power or discharged as appropriate (report tolerance: ±5%). Check contactor points for severe arcing, carbon pitting, or fire ant infestation.
Verify the outdoor disconnect fuse/breaker does not exceed the 60 A MOCP and that supply conductors meet the 37.3 A MCA.
Inspect coil fins for biological growth, dirt coating, or formicary corrosion and pinhole leak risk. Inspect the composite/poly drain pan for warpage, cracks, or threaded drain port damage.
Confirm the blower is a variable-speed ECM to modulate airflow between Stage 1 (approximately 1,400 CFM) and Stage 2 (approximately 2,000 CFM). Check wheel cleanliness.
Inspect the return plenum and coil transitions for air leaks. Check media filter rack sizing, gasket seal, and ease of filter replacement in the attic.
Insert static pressure probes into supply and return plenums. Measure total system pressure with all zones calling, then with each individual zone calling. Pay particular attention to the smallest zone (Zone 3).
Cycle thermostats individually. Verify each motorized damper blade fully opens and seats without humming, binding, or air bypass whistle.
Check whether a bypass duct is present and properly weighted. Confirm the zone board includes an operational Discharge Air Temperature (DAT) sensor to downstage or shut down before the coil drops below the report’s 34°F reference.
Inspect attic flex ducts for tight bends, kinks, sagging runs, or outer vapor barrier tears. Verify strong velocity at upper-floor supply grilles.
Source report advisory: a 5.0-ton system requires approximately 2,000 CFM on high stage. With only one small zone calling, closed dampers may create severe backpressure. If TESP exceeds 0.80 in. w.c., verify that Stage 1 reduces capacity or the bypass relieves excess volume without freezing the evaporator. Verify operating limits against manufacturer guidance.
Verify a 3/4-inch PVC line with positive slope (report reference: at least 1/8 inch per foot), functional P-trap, and accessible cleanout tee. Ensure the cleanout cap upstream of the P-trap is airtight to prevent negative-pressure suction overflow in draw-through attic coils.
Inspect the secondary pan under the attic unit for standing water, rust, or cracks. Test the inline float and emergency pan switches to confirm cooling cutoff.
Verify the secondary overflow line terminates outside above a prominent window or soffit where drips signal a clog. Confirm lines in the unconditioned attic are insulated to prevent condensation drips.
If a gas furnace is present, inspect the burner assembly for rust or delayed ignition. Check heat exchanger cells for cracks or flame rollout. Verify flue pipe slope and draft inducer; measure ambient CO at supply grilles. Mark N/A if not applicable.
If an electric air handler is present, test sequential heating element staging. Measure operating current across each heat strip bank to confirm element continuity and limit switch function. Mark N/A if not applicable.
Record brand, model, and rated daily capacity. The source report expects 70–120 pints/day for a 2,500 sq ft home. Slide out and inspect the internal washable / MERV filter.
Inspect return/supply tie-ins. Verify the gravity backdraft damper is functional so central AC airflow does not blow backward into the dehumidifier.
Lower the RH setpoint to 40% (below ambient room RH). Verify the unit starts independently without requiring an active cooling call from the AC.
Confirm whether the dehumidifier control board cycles the main HVAC variable-speed blower at low speed to distribute dry air evenly.
Inspect the dehumidifier drain line, dedicated P-trap, and secondary pan/float. Ensure the condensate line drains directly to an approved disposal location.
Source report advisory: in mild Texas spring and fall conditions, cooling may satisfy temperature before removing enough humidity. Verify the dedicated dehumidifier can maintain indoor humidity below the report’s 50% RH reference independently, to limit moisture accumulation and microbial growth.
Force the system into Stage 2 (Y2 / 100%) and run for at least 15 minutes to stabilize before recording measurements. Test subcooling (charge volume) and superheat (TXV metering health). Report references: 14°F subcooling and 8–18°F superheat.
Measure return and supply air temperatures at the main coil plenum during high-stage cooling. The report’s target split is 15–20°F.
Check all 3 thermostats for 24V C-wire presence. Confirm zone board lights correctly display calls and dispatch Y1 / Y2 stages.
No defects recorded.
System status: Not recorded