AC Drain Line Clogged? Clear It With a Shop Vac, No Parts

Updated 2026-09-03 · Sources verified 2026-07-20

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Short answer: no permit to clear it. Clearing or treating the condensate line is maintenance on an existing system. The full answer and its source are below, with the code requirements and mistakes that trip up Orlando homeowners.

The permit answer

Orange County and the City of Orlando run separate permit offices with separate portals — and your mailing address alone doesn't tell you which one covers your home. Check which permit office covers your address →

Key facts before you start

• Size, slope, and where it may legally end: 3/4-in nominal minimum (FBC-M 307.2.2 — the sizing table only steps up past 20 tons, so every house is 3/4 in) and the line may NEVER reduce downstream; code slope is 1/8 in/ft (307.2.1) but Goodman requires "a minimum of 1/4\" per foot," so use the stricter figure, support the line against bowing, and insulate any run over finished space. 307.2.1.1: a condensate drain "shall not directly connect to any plumbing drain, waste or vent pipe" — approved discharge is a floor sink, floor drain, or utility sink within the same dwelling unit, so tying into a lav tailpiece or a vent stack is a violation, not a shortcut.
• Don't crack the drain pan: the pan's 3/4-in NPT female ports take a 3/4-in NPT male PVC or metal fitting HAND-tightened to no more than 37 in-lbs — Goodman expects only 3/8 to 1/2 in of insertion (3-5 turns) at that torque, and wrenching it further splits the pan boss. Use only the ports you actually pipe: Goodman — "If secondary drain is not installed, the secondary access must be plugged"; Rheem — knock out only the connection(s) to be used, because "knocking out plastic webs on unused drain connections can cause condensate to flow out the holes resulting in property damage."
• Trap it the way the MAKER says — 307.2.4 defers entirely: "Condensate drains shall be trapped as required by the equipment or appliance manufacturer." Goodman requires a "P" style trap as close as practical to the coil with a positive liquid seal, because a draw-through air handler holds the pan under NEGATIVE pressure — without a primed trap the blower pulls air up the drain and the pan won't drain at all (overflow with a 'clear' line). Prime it at install and at the start of each cooling season. An open vertical tee between the air handler and the trap is NOT forbidden: Goodman says it "can improve condensate drainage in some applications" but does not recommend it because of air discharge out of the tee. Ductless mini-splits instead need an inline check valve OR a trap (307.2.4.1).
• AC dead in summer = check the float switch FIRST before condemning parts. FBC-M 307.2.3/307.2.3.1 require a UL 508 water-level shutoff (RectorSeal SS1 inline on the primary line, SS2 on the primary pan's auxiliary outlet) that kills the 24V control circuit — connect either the red or yellow leg — so standing water at the switch means a clogged drain, not a failed board; downflow coils and any coil with no secondary drain need the sensor in the primary pan. Same rule for a condensate pump: Goodman permits one but it "should have provisions for shutting off the control voltage should a blocked drain occur," needs a trap between the unit and the pump, and neither pump nor float switch may contain styrofoam or plastics the coil's oils dissolve.
• Chemicals vs. clearing: NEVER pour bleach or caustic drain cleaner in the pan or near the coil — Rheem: "Do not use caustic household drain cleaners in the condensate pan or near the indoor coil. Drain cleaners will quickly damage the indoor coil." Trane and Carrier both allow ONE CUP of distilled vinegar at the indoor access point, but only as prevention — Carrier notes vinegar or bleach "may not fully prevent blockages because many clogs are caused by debris or buildup that is not organic material." Clear an actual clog mechanically and always from the far end: wet/dry vac sealed onto the 3/4-in termination OUTSIDE (Carrier), or per Rheem remove the drain line "from the unit away from the pan and coil" and flush it with high-pressure water. Never blow compressed air toward the air handler. FBC-M 307.2.5 requires drains be configured to clear blockages WITHOUT cutting the pipe — if there's no cleanout tee, add one.
• Attic/above-ceiling air handlers: FBC-M 307.2.3 requires an auxiliary pan at least 1-1/2 in deep and 3 in larger than the unit in width and length (galvanized min 0.0236 in / No. 24 gage), draining to a CONSPICUOUS point — usually over a window or soffit. Goodman: "Water coming from secondary line means the coil primary drain is plugged and needs immediate attention," so shut cooling off rather than letting it run. Flushing/vacuuming the line and like-kind minor-part replacement (float switch) is permit-exempt maintenance under FBC 105.2; re-piping condensate or replacing the coil/air handler needs a licensed contractor + an Orange County mechanical permit (OC requires one for all permanently installed AC/heating equipment; City of Orlando is a separate office). Warranty note — Trane: "Going the DIY route could void your warranty," so on an in-warranty system call before cutting anything.

What it costs

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Frequently asked questions

Do I need a permit for a HVAC condensate line repair in Orange County, FL?

No permit to clear it. Clearing or treating the condensate line is maintenance on an existing system. Replacing the AC or air handler itself is a mechanical changeout that always needs Orange County's mechanical permit — plug-in portable units are the only exception.

Are there specific building-code requirements for a HVAC condensate line repair?

Size, slope, and where it may legally end: 3/4-in nominal minimum (FBC-M 307.2.2 the sizing table only steps up past 20 tons, so every house is 3/4 in) and the line may NEVER reduce downstream.

What tools or parts do I need to get right for a HVAC condensate line repair?

Don't crack the drain pan: the pan's 3/4-in NPT female ports take a 3/4-in NPT male PVC or metal fitting HAND-tightened to no more than 37 in-lbs — Goodman expects only 3/8 to 1/2 in of insertion (3-5 turns) at that torque, and wrenching it further splits the pan boss.

What does a HVAC condensate line repair cost?

DIY: Essentially free in parts — HomeGuide's DIY method is 1/4 cup distilled white vinegar poured in the line monthly, then a hot-water flush (pantry-item cost; a wet/dry shop vac you may already own helps pull stubborn clogs). The source publishes no separate DIY dollar figure. Hiring it out: $75–$250 for a professional AC flush to unclog the condensate drain line Skipping the flush risks drain-pan overflow and water damage — the same page prices primary drain pan replacement at $600–$1,200. Published national figures (HomeGuide, checked Aug 2026) — local prices vary, and the free DIYrr planner pulls current retail prices for your exact repair.

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Sources

https://up.codes/viewer/florida/fl-mechanical-code-2023/chapter/3/general-regulations
https://codes.iccsafe.org/content/FLMC2023P1/chapter-3-general-regulations
https://documents.alpinehomeair.com/product/Goodman%20AVPTC14%20oddnum%20Installation%20Instructions.pdf
https://cdn.bakerdist.com/rheem_rcba-uncased_en_ii.pdf
https://www.trane.com/residential/en/resources/troubleshooting/air-conditioners/ac-drain-line-clogged/
https://www.carrier.com/residential/en/us/products/air-conditioners/air-conditioner-maintenance/how-to-clean-ac-drain-line/
https://rectorseal.com/safe-t-switch-legacy-group/
https://documents.alpinehomeair.com/product/rectorsealsafteyswitchbrochure.pdf
https://up.codes/viewer/florida/fl-building-code-2023/chapter/1/scope-and-administration

This guide is general informational content, not professional or legal advice. Codes and county rules change — confirm permit requirements with your local building department, and use a licensed professional for electrical, gas, structural, or main-line plumbing work.

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