Yes, it’s Okay if Your HVAC is Connected to Your Sink Drainpipe

Drains and HVAC systems are not a topic of conversation that comes up all too often – especially around the table with friends. Let’s face it: you aren’t dreaming about your pipes and looking for the next opportunity to share information about our new  If you’ve never thought about it before, I can guarantee that the first sign of a leak can be a swift education for most of us. Many homeowners may not realize that they actually have drains connected to an upstairs HVAC, but they’re there, and it’s important to know all you can as the Texas winter sets in for the long haul.

Plumbing and HVAC Drain Lines in Your Home

For most newer homes, you’ll more than likely find that your HVAC condensate drains are tied to bathroom drains.

Standard drain line placements may include:

• Your bathrooms (sinks, shower or tub, toilet)
• The kitchen (sink, water line to the freezer)
• Laundry room
• Water heater

It is prevalent in new homes (because city codes require it) for drain lines to run from the air conditioner’s condensate line, which are often located in the attic, to the home’s plumbing system.

So, the quick answer is yes. It is completely normal and okay for your HVAC to be connected to the upstairs sink drainpipe.

Why? Any water collected by the condensate drain can be easily drained out of the home through larger pipes that will eventually meet at the home’s sewer line.

The trap in the bathroom sink can also prevent the gasses from the sewer from seeping their way into your home and air conditioning system.

In older homes, you might not always see this same setup. Often the evaporator coil is busy both removing humidity and cooling the air with refrigerant; in this case, lines are not tied to a home’s plumbing system. They may have a separate exit point from the home.

If You Ever Experience Clogs

The number one rule: skip harsh chemical-based drain-clearing products, like Drano or Liquid Plumr. These can cause damage to the fixtures and pipes, not to mention that it is dangerous for people around it. If you have a slow drain, make sure to have it fixed right away. In addition, If the slow drain is the bathroom sink, you can just remove the p-trap (the curved pipe underneath the sink) to clean out any clogs pretty easily.

A slow-draining sink that is tied to your home’s HVAC system can be a plumbing nightmare waiting to happen. From leaks to backups, take care of any problems you see ASAP.