Home A/C Replacement Issue

[bernorange 8385]

21 year old two story house in the outlying Houston area.  We have two A/C units - 5 ton unit for the downstairs.  3 ton unit for the upstairs.  Both units original to the house when built, so 21 years old.

We've had issues with the A/C units for the last several years.  Every summer, we have to flush the drains by the sinks inside the house where the main drain lines for the units connect as they clog up and the A/Cs stop working.  This year, I noticed the secondary drain line outside dripping non-stop (even first thing in the morning).  Drains in the house working fine, so lines not clogged (at least, not from the upstairs sinks on down).  Called A/C guy out and discovered that evaporator unit in the attic seems to have a cracked/leaking basin/pan inside the unit - it's dripping water down both main drain and secondary drain.  Not really fixable.  Time to replace the unit.

Side note:  we replaced tanked water heaters with a tankless system several years ago.

A/C company comes out yesterday and replaces the 5 ton unit with the leaking issue.  Unfortunately, they are unable to unclog the main drain line from the evaporator to the upstairs sink.  They replaced the piping in the attic and the hose at the sink, but the line in the wall is FUBAR.  They connected the main drain line for the 5 ton unit to the old (1") drain a line from one of the old tanked water drain lines.  This ensures water is dripping out a pipe near the foundation on the side of the house.

A/C guy says best solution is to install a French drain at the pipe and leave the main drain connected to the old water heater drain line.

I'm wondering if there will be less headaches down the road if we tear open the wall and install a new drain line to connect to the sink drain like the old system did.

Anyone have any experience in this area?

[MonkeyDoughnut 10805]

No experience, but I'm hoping you rip the wall open as I really can't think of what might have caused that line in the wall to clog such that they couldn't clear it and want to find out what it was.

[Homercles 10206]

47 minutes ago, MonkeyDoughnut said:

No experience, but I'm hoping you rip the wall open as I really can't think of what might have caused that line in the wall to clog such that they couldn't clear it and want to find out what it was.

[Jkwellborn 7040]

Did they give you a kiss when they fucked you? I feel like they were bullshitting you on being able to replace the drain pan. I mean, they make the damn things.

I don’t understand the drainage problem. I’d call a plumber and not an AC guy on that. Have you poured any bleach down the drain to kill the shit that builds up?

[bernorange 8385]

1 hour ago, Jkwellborn said:

... on being able to replace the drain pan. ...

I don’t understand the drainage problem. ...

It's not the drain pan which sits under the unit to collect water for the secondary drain line.  It's a pan/tank/whatever inside the evaporator which collects the water for the main drain line.  It's leaking and water has been dripping all over for who knows how long.  Pictures of the underside of the evaporator show major corrosion of all metal surfaces.  Rust and shit has been washing into the drain lines and the line from the attic to the second floor sink drain is clogged.  They tried to clear it with a snake, air pressure and something else I can't remember right now.  Nothing worked.  The guys spent at least 1-2 *extra* hours working in the 120F attic because of this.  

[Jkwellborn 7040]

Those coils come with a drain for horizontal mounting(dumb shit) bolted to the side inside the case and then the normal pan that it actually sits in and drains to when it’s vertical. I will never for the life of me understand why anyone willingly chooses to put those things in the attic.

[Gatorubet 30722]

21 year old two story house in the outlying Houston area.  We have two A/C units - 5 ton unit for the downstairs.  3 ton unit for the upstairs.  Both units original to the house when built, so 21 years old.
We've had issues with the A/C units for the last several years.  Every summer, we have to flush the drains by the sinks inside the house where the main drain lines for the units connect as they clog up and the A/Cs stop working.  This year, I noticed the secondary drain line outside dripping non-stop (even first thing in the morning).  Drains in the house working fine, so lines not clogged (at least, not from the upstairs sinks on down).  Called A/C guy out and discovered that evaporator unit in the attic seems to have a cracked/leaking basin/pan inside the unit - it's dripping water down both main drain and secondary drain.  Not really fixable.  Time to replace the unit.
Side note:  we replaced tanked water heaters with a tankless system several years ago.
A/C company comes out yesterday and replaces the 5 ton unit with the leaking issue.  Unfortunately, they are unable to unclog the main drain line from the evaporator to the upstairs sink.  They replaced the piping in the attic and the hose at the sink, but the line in the wall is FUBAR.  They connected the main drain line for the 5 ton unit to the old (1") drain a line from one of the old tanked water drain lines.  This ensures water is dripping out a pipe near the foundation on the side of the house.
A/C guy says best solution is to install a French drain at the pipe and leave the main drain connected to the old water heater drain line.
I'm wondering if there will be less headaches down the road if we tear open the wall and install a new drain line to connect to the sink drain like the old system did.
Anyone have any experience in this area?

[bernorange 8385]

I called the city and asked if using the old water heater drain was code compliant and they said it would be if the drain ended in a French Drain (bucket with pea gravel).  It's not what I want, but it's likely what I'm going to get (for now).