Like the title says, I want to replace my existing AC drain lines for two units located in my attic. This includes potentially rerouting the drain lines to different plumbing fixtures in our second floor bathrooms.

Should I call an HVAC company or a plumber? If either, would one be cheaper than the other?

Mechanical guys would normally handle but in residential a plumber can run a line just as easily. Even a handyman could probably help you out.

I would vote for Plumber !

Plumbers care to a different degree than many HVAC techs/ installers when it comes to drain lines. Highly trained HVAC guys don't usually mess with drain lines, those jobs tend to go to lower hourly paid ppl and drain lines can cause lots of complaints/ issues if not done AND cleaned properly at some point in time.



Seems like a simple job with drain lines but tools, skill set, and degree of knowledge all factor in with how your system drips and where. Fix it right the first time so no issues in 10 years from now.

Yeah , definitely get a plumber for that. HVAC guys installed a new system for my neighbor and they just ran the drain line in the attic out to the soffit area without extending it out thru the soffit. When his system backed up last year, it overflowed onto his soffit and the soffit panel eventually deteriorated, warped and fell loose...

What's current code for drain lines and right way for the primary? At some point the prior owners replumbed the primary drain lines to drain to the exterior with PVC running down the side of my house to about 6 inches of the ground. Previously they drained to the upstairs sinks as I can see the connection to both.

The secondary lines still drain above through the soffits above Windows.

Edit to add I've only seen primary drain lines routed to sinks before and I believe that is to code.

We did the same thing and both a plumber and A/C guy came and did the job.