Warmer temps are here - attic furnace drip pan filling fast

You don't have a pump to move this out of the house?

Is it the pan under the coil or the overflow pan under the unit?

Unless you have some type of weird, not to code install, it sounds as though your primary drain is plugged and the condensate water is overflowing into your secondary emergency drain pan.

You, or a HVAC tech, need to clean or remove any obstruction in the primary drain line. When this has happened to me, I’ve been able to clean the primary drain every time by pouring bleach via the condensate drain line vent tube, connected to drain line, next to the furnace/cased evaporator coil. If the obstruction/blockage is in between the vent tube and the evaporator coil, then a tech would either use compressed air or suction to clear it.

Once clear, maintain the drain line by pouring vinegar 3 or 4 times a year down the vent tube/and or adding chlorine tablets a couple times a year to the primary drain pan inside the cased evaporator coil.

TLDR: if you have water collecting in your secondary drip pan, your primary drain line is plugged, and it needs to be cleaned, either by you or a HVAC tech.

quote:

---

Running the fan only will make the conditioned space more humid and not cooler during summer.

---

Unless you add moisture it won't make it more humid but it will also not make it cooler. Eventually, it will actually warm the air even if the attic is not much warmer. Warming the air will actually reduce the relative humidity unless there is available moisture added to the air.

I will clarify. This is the emergency drain pan (with the shutoff switch that will cut power to the furnace when water fills). Based on what everyone is saying, seems like I just need to do a full on cleaning of the drain.

GOT to add bleach to the line every year at minimum. Just a 1/2 cup will do. For now i would say blow with compressed air then follow by bleach.

quote:

---

I just need to do a full on cleaning of the drain.

---

this ^^^^^^

cut the line right near the coil box and then blow into the line as hard as you can, that will push the blockage out of the line.

then if water wasnt pouring out of the coil box after you cut the pipe, stick something soft in the line to did out whatever is blocking it.

use a stick or something and swirl it around until you see the water start coming out. if there was no water in there than your main coil pan rusted out and the coil pan or the coil itself needs to be replaced to fix it

when you are done put a tee to reconnect the line with a short pipe on top with a cap on it so you can remove the cap to add a little bleach every few months.

i dont glue the tee fitting to the pipe, so if it gets blocked again you can just pull the fitting back off of the coil box drain line to clear it. it has no pressure, so fittings can be just pushed on and it still seals it perfectly fine

quote:

---

We actually have T pipe connection and it flows well. I think it's usually just some minor blockage, but we've never really done a thorough cleaning with any type of chemicals. The most I've ever put is hot water that was recently boiling. It's just a big pain to have to crawl through the back of the attic due to the drain being in a very inconvenient spot.

---

doesnt need much, just an ounce of bleach in it every 2 months is good enough to stop mildew growing to clog things up.

just be sure to cap the tee, you dont want to create a ready made water source for mice.

pan under unit should stay dry unless the main drain line is clogged, or the pan inside no longer holds water

oh, another tip is, if the coil box end seems clogged, use a shop vac to suck the clog out, so your not pushing clumps of shite back in trying to unblock it

toss a chlorine puck in there