Where do condensate lines drain to?

Author: Wilson Kilback  |  Last update: Sunday, December 21, 2025

In new homes, city codes require drain lines from the air conditioner's condensate line which are often located in the attic to tie in or be plumbed to the home's plumbing system. Typically, those 3/4″ pipes are plumbed into a bathroom sink's drain that is on average 1-1/4″ or 1-1/2″ in diameter.

Where should a condensate pipe drain to?

Where an installer is fitting a new or replacement boiler, the condensate discharge pipe should be connected to an internal “gravity discharge point” such as an internal soil stack (preferred method), internal kitchen or bathroom waste pipe such as sink, basin, bath or shower waste.

Can AC condensate drain to the ground?

The most popular areas we terminate condensate drain lines to is the side of the house and usually about six inches from the ground. And this can be in a planted area that is large enough to accept the amount of drainage, and soak down into the earth.

Can condensate drain to the sewer?

Condensate drains shall not directly connect to any plumbing drain, waste or vent pipe. Con- densate drains shall not discharge into a plumbing fixture other than a floor sink, floor drain, trench drain, mop sink, hub drain, standpipe, util- ity sink or laundry sink.

What are the rules for condensate drain lines?

Condensate drains shall not directly connect to any plumbing drain, waste or vent pipe. Condensate drains shall not discharge into a plumbing fixture other than a floor sink, floor drain, trench drain, mop sink, hub drain, standpipe, utility sink or laundry sink.

Furnace Troubleshooting Condensate Piping

Where should an AC condensate line drain to?

Condensate lines should terminate in a location that allows for safe and effective drainage. This can include outdoor areas, a nearby floor drain, or a dedicated drain connected indirectly to your plumbing system to prevent contamination.

Should a condensate pipe go into the ground?

Your condensate pipe can terminate above or below ground. If above ground, however, you will have to have it lagged.

Where does the condensate pump drain to?

Generally, there are different places where you can drain the water; these might include underground drain pipes, catch basins, or gardens. One excellent option here is to connect your condensate drain line to a sink.

Can condensate drain go to storm drain?

Different municipalities may require condensate be disposed of to the sanitary sewer, while others may require disposal to building exterior or storm drainage piping. Some AHJ may even require the use of additional equipment to neutralize certain elements/compounds prior to disposing of the condensate.

Should water be coming out of condensate pipe?

Leaks with a constant flow rather than slow drip can mean a condensate pipe has become disconnected or punctured. If that's the case, it's important to get your HVAC system serviced as soon as possible to avoid additional problems including further damage to your house.

Can HVAC condensate drain outside?

The pipes dip in a trap close to the coil end of the pipes. The trap resembles a shallow U-shape. The bend lives up to its name as it traps gas from your drainage lines. After the trap section, the AC condensate drainage pipe continues on to the outdoors or to one of your structure's other drain lines.

What is the code for condensate discharge?

307.2. 1.1 (IPC [M] 314.2. 1.1) Condensate Discharge.

Where does AC drain water go?

It carries the water from your indoor unit outside and deposits the water onto your grass. Your drain line often travels from your indoor units to outdoors near your external AC units. If you walk outside and look near your HVAC system, you may see a pipe connected to your home.

Should condensate line be full of water?

The drain pan and condensate drain line in an AC unit move residual water from the system to outside your home. If you have an AC drain pan full of water, it can lead to leaks, bacteria and algae buildup, and water damage. Leaks can also be a sign of future problems with other AC system components.

How do I know where my condensate pipe is?

Where is the condensate pipe? The condensate pipe runs from the boiler to a suitable existing waste pipe system, or external drain pipe. If it is connected to an external drain pipe, it will be found outside your property leading out from your boiler.

Can a condensate pipe go into a gutter?

It is possible to terminate a condensate pipe into a rain water down pipe that terminates into the foul waste system. As with all externally-run condensate pipes, it is recommended to keep the external run to minimum and the pipe diameter to 32mm when exiting the property.

Where can I drain my condensate line?

In newer homes, HVAC condensate drains are tied most often to bathroom drains. Common drain lines inside your home include in your bathrooms (sinks, shower or tub, toilet), kitchen (sink, water line to your freezer), laundry room, and water heater.

What are the rules for condensate drains?

The IMC dictates a 1% minimum pitch of the drain, equal to 1/8″ fall for every 12″ (foot) of horizontal run. In practice, it is safer to use 1/4″ of fall per foot to ensure proper drainage and provide some wiggle room for error.

Can a condensate pipe go into waste pipe?

Where should a boiler condensate pipe go? The HHIC states that: “When fitting a new or replacement boiler, the condensate discharge pipe should be connected to an internal 'gravity discharge point', such as an internal soil stack, internal kitchen or bathroom waste pipe such as sink, basin, bath or shower waste.

Can you drain condensate into the sewer?

Most jurisdictions will not allow condensate discharge in the sanitary sewer system. Disposing condensate into sewer systems creates hundreds of gallons of water that must be treated daily during hot summer months.

Why is my AC condensate drain line constantly dripping?

Over time, this line can become clogged with algae, dirt, dust, and debris. When this happens, the line backs up and overflows from the drain pan, causing the water to leak into your home. You can unclog the drain line by removing the debris with a wet/dry vac.

How to tell if a condensate line is clogged?

Signs of An AC Drain Line Clogged
  1. Musty, moldy smell near your indoor unit or in air from the registers/vents.
  2. Standing water near the indoor unit.
  3. Water damage in areas near the indoor unit.
  4. AC system is not cooling your home.
  5. AC system shuts down or doesn't turn on.

Does condensate line drip in winter?

Regardless of the season or whether you are in heating or cooling mode, a heat pump produces a certain amount of condensation. During the winter, the outdoor unit will drip water under your heat pump as a normal part of the evaporation process.

How much water should come out of the condensate pipe?

Usually being released in 300ml increments (often the reason you may hear water transportation through the pipes when your boiler is operational).

Can a drain pipe go straight into the ground?

UK building codes require downpipes to exit a metre from foundations to avoid saturated soil that could undermine structures. Surface drains and soakaways are best as they slowly absorb water, unlike sewers which risk flooding if pipes discharge directly into them as this can overwhelm the drain system.

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