Zooglea Blocking Drain Line on AC

[laportjm]

As anyone experienced multiple shutdowns of their AC this summer due to Zooglea bacteria building up and water backing up and shutting down AC. It has happened once a month since June. We are being told this has been a very common service call this summer. We are going on our 5th year with this new AC and has never had this problem. One issue we have experienced is our Wi-Fi thermostat is kicking the temperature from what we set at 78 and holding and something within the unit is tripping the thermostat back to 74. So obviously the AC is running unnecessarily pretty much all summer. We are not physically there so we are unable to see what it is doing from time to time. 2 times it was noticed and specifically put to 78 and holding (I don’t know what this “holding” feature is but it has always done that since install) but never has it kicked itself back to a much lower temp than we have set. We have lost internet and believe our gateway is toast so we are unable to keep an eye on it. We will be there in the next couple weeks and have neighbor and relatives that are able to help us out until we get there. Anyone experiencing this Zooglea bacteria and a thermostat doing such as described. Thank you.

[Bill14564]

By any chance does your system have a humidity setting? It *could* be that as the gunk builds up and water stands in the drain pan it is causing the humidity to increase. In response, the humidity control of the system might lowering the set temperature to try to bring the humidity back down. Just a guess.

I do have a friend who has had a terrible time with his lines this year. He flushes them and cleans them but still has trouble.

[CarlR33]

Are you flushing the AC drain line at all? If not that is your issue. We would need to know the brand of thermostats to help you there. If an ecobee it has a permanent hold feature like most other smart thermostats.

https://www.talkofthevillages.com/forums/villages-florida-general-discussion-73/ac-line-tray-cleaning-best-process-359616/?highlight=Drain+line+flush

[retiredguy123]

I have not heard of the Zooglea issue being a problem in The Villages. How do you know that is the problem? When you set the thermostat to 78 degrees and "hold" it should stay on 78 until you change it. That is what the hold setting means. It sounds like you need to get an HVAC technician to thoroughly clean out the entire condensate drain pipe, which could have an obstruction in it. Then, you need to pour a gallon of hot water down the drain every month or so. If the thermostat is being reset to 74 degrees, you will get more condensate water flowing, and if you have an obstruction, it could cause the water back up into the drain pan. It is amazing how much water flows through the drain pipe in the summer, especially with a thermostat set at 74 degrees. If you have the optional humidity feature turned on, turn it off.

[Bill14564]

I have not heard of the Zooglea issue being a problem in The Villages. How do you know that is the problem? When you set the thermostat to 78 degrees and "hold" it should stay on 78 until you change it. That is what the hold setting means. It sounds like you need to get an HVAC technician to thoroughly clean out the entire condensate drain pipe, which could have an obstruction in it. Then, you need to pour a gallon of hot water down the drain every month or so. If the thermostat is being reset to 74 degrees, you will get more condensate water flowing, and if you have an obstruction, it could cause the water back up into the drain pan. It is amazing how much water flows through the drain pipe in the summer, especially with a thermostat set at 74 degrees. If you have the optional humidity feature turned on, turn it off.

I'm confused by this. Are you simply saying that the algae/gunk that builds up in the lines is technically something other than zoogloea? Or, is there some other reason you pour hot water through the line every month?

[retiredguy123]

I'm confused by this. Are you simply saying that the algae/gunk that builds up in the lines is technically something other than zoogloea? Or, is there some other reason you pour hot water through the line every month?
I have just never heard of an HVAC technician ever diagnose "zoogloea" as a specific cause for a drain being clogged. The OP said it is very common in The Villages, but I am skeptical that this is true. It seems as though you would need to do a lab test to confirm that it was bacteria. There are many ways a drain line can be clogged. My biggest concern is a dead lizard or snake. That is why I occasionally flush out the drain by connecting a garden hose to it. The last two times I did this, I got a lot of chalky white solid particles, which I really don't what they were.

[Bill14564]

I have just never heard of an HVAC technician ever diagnose "zoogloea" as a specific cause for a drain being clogged. The OP said it is very common in The Villages, but I am skeptical that this is true. It seems as though you would need to do a lab test to confirm that it was bacteria. There are many ways a drain line can be clogged. My biggest concern is a dead lizard or snake. That is why I occasionally flush out the drain by connecting a garden hose to it. The last two times I did this, I got a lot of chalky white solid particles, which I really don't what they were.

When mine was clogged it was definitely a clear or milky, slimy algae-like substance. Probably was zoogloea but it wasn't worth paying for a lab test to confirm that.

The purpose for the hot water or vinegar or bleach is to kill any algae growing in the line. If anoles were the problem then flushing with cold water would be all that was needed.

An anole issue can be prevented with a small piece of mesh over the opening.

[jrref]

No bleach. Bleach will harm the PVC. Hot water, vinegar, Top Job, pretty much anything else should be fine. If your drain is maintained once a month, Hot Water is all you need.

[Altavia]

By any chance does your system have a humidity setting? It *could* be that as the gunk builds up and water stands in the drain pan it is causing the humidity to increase. In response, the humidity control of the system might lowering the set temperature to try to bring the humidity back down. Just a guess.

I do have a friend who has had a terrible time with his lines this year. He flushes them and cleans them but still has trouble.

The HVAC techs place tablets in the drain pan to deactivate the bacteria that form the slime.

https://a.co/d/1DMKbi6

Here's a system that automatically treats the line periodically.

https://a.co/d/9JLwmEp

[Altavia]

I have just never heard of an HVAC technician ever diagnose "zoogloea" as a specific cause for a drain being clogged. The OP said it is very common in The Villages, but I am skeptical that this is true. It seems as though you would need to do a lab test to confirm that it was bacteria. There are many ways a drain line can be clogged. My biggest concern is a dead lizard or snake. That is why I occasionally flush out the drain by connecting a garden hose to it. The last two times I did this, I got a lot of chalky white solid particles, which I really don't what they were.

The white, slimy, snot like stuff that forms if you don't regularly flush the system is Zoogloea bacteria.

https://youtu.be/5VOffWjmWkk

It became a problem when HVAC systems switched from copper to aluminum. Very low concentrations of copper ions deactivate the bacteria preventing the build up.

Some of the tablets (if blue) used to prevent HVAC Zoogloea build up contain copper sulfate.

[Topspinmo]

Maybe power fluctuations cause the setting problems?

IMO if anyone not living in house why do have set at 78? If I wasn’t here I’d set it to 85 or at least 80, it probably run 1/3 less. But, that me. Please tell us when the condensation drain was last cleaned/ blown/ sucked out? That way maybe someone can pinpoint cause of the problem? Said system was 5 years old? Has condensation drain ever been sucked out?

[laportjm]

Thanks everyone for your responses. All very good questions. We are gone from April to usually Oct and come and go from that point to April. We now know that we need to get our system cleaned twice a year instead of one so that is part of our problem. However, we have only cleaned it once a year since install just about 5 years ago and never encountered this problem. When we leave we do the vinegar and water cleaning/flush. This has been the only year that we had to have a tech come out June 30, July 31, and Aug. 9 due to back up issues and shutting the system down. The evaporator coil was replaced in April apparently there was a leak. I asked is that the start of the problem and I was told no. So not really sure what is causing the amount of bacteria so we will be cleaning it in Oct and April. However the 2nd issue about the Eccobee thermostat that we determined today is that apparently there is a setting within the thermostat that when it detects movement in the house it automatically reverts to 74 degrees. So when my neighbor went in one time and my cousin another, it detected movement and went to 74 so to them they saw 74 as the thermostat detected them and immediately changed to 74. My husband found where that setting is and changed to 78. Yes I agree someone mentioned why 78 should be more like 80 which we had done in the past and for some reason we started leaving it at 78. The Tech determined that it was zooalgea. I believe that, as where it drains onto our stones, it is a slimy, white substance (snotty as someone stated). Of course, we were immediately offered a couple options at a price higher than I want to pay at this point without trying a less expensive route first. Again thank you all for your responses, greatly appreciated.

[tophcfa]

The white, slimy, snot like stuff that forms if you don't regularly flush the system is Zoogloea bacteria.

https://youtu.be/5VOffWjmWkk

It became a problem when HVAC systems switched from copper to aluminum. Very low concentrations of copper ions deactivate the bacteria preventing the build up.

Some of the tablets (if blue) used to prevent HVAC Zoogloea build up contain copper sulfate.

Good information, Thanks. This drain snot problem very well might apply to us since we have a new HVAC system that’s less than a year old. I’m going to do some investigating to see if our new system has aluminum condenser coils and take appropriate preventative measures if so. It’s troublesome how changes to technology can have negative ripple effects, like adding ethanol to gasoline, or changing from using copper to aluminum for an HVAC systems condenser coils.

[Jimbo120]

PM me for specifics but I purchased a small drain Bladder at Lowes for around $40 which goes in the overflow pipe and reaches below the pipe going back in the system (important) The bladder is attached to a water hose and allows the full force of the water to clear the pipe. Some people put a shut off on the bladder to keep from having to run back to the spicket to turn off the water.









As anyone experienced multiple shutdowns of their AC this summer due to Zooglea bacteria building up and water backing up and shutting down AC. It has happened once a month since June. We are being told this has been a very common service call this summer. We are going on our 5th year with this new AC and has never had this problem. One issue we have experienced is our Wi-Fi thermostat is kicking the temperature from what we set at 78 and holding and something within the unit is tripping the thermostat back to 74. So obviously the AC is running unnecessarily pretty much all summer. We are not physically there so we are unable to see what it is doing from time to time. 2 times it was noticed and specifically put to 78 and holding (I don’t know what this “holding” feature is but it has always done that since install) but never has it kicked itself back to a much lower temp than we have set. We have lost internet and believe our gateway is toast so we are unable to keep an eye on it. We will be there in the next couple weeks and have neighbor and relatives that are able to help us out until we get there. Anyone experiencing this Zooglea bacteria and a thermostat doing such as described. Thank you.

[Jimbo120]

When the system is partially clogged it usually builds up water during use during the day and slowly drains out at night. What you experience is the system shutting down during the day and suddenly is running again in the morning.



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As anyone experienced multiple shutdowns of their AC this summer due to Zooglea bacteria building up and water backing up and shutting down AC. It has happened once a month since June. We are being told this has been a very common service call this summer. We are going on our 5th year with this new AC and has never had this problem. One issue we have experienced is our Wi-Fi thermostat is kicking the temperature from what we set at 78 and holding and something within the unit is tripping the thermostat back to 74. So obviously the AC is running unnecessarily pretty much all summer. We are not physically there so we are unable to see what it is doing from time to time. 2 times it was noticed and specifically put to 78 and holding (I don’t know what this “holding” feature is but it has always done that since install) but never has it kicked itself back to a much lower temp than we have set. We have lost internet and believe our gateway is toast so we are unable to keep an eye on it. We will be there in the next couple weeks and have neighbor and relatives that are able to help us out until we get there. Anyone experiencing this Zooglea bacteria and a thermostat doing such as described. Thank you.

[retiredguy123]

PM me for specifics but I purchased a small drain Bladder at Lowes for around $40 which goes in the overflow pipe and reaches below the pipe going back in the system (important) The bladder is attached to a water hose and allows the full force of the water to clear the pipe. Some people put a shut off on the bladder to keep from having to run back to the spicket to turn off the water.
I have basically the same thing that I bought from Amazon for about $12. It works great.

Amazon.com (https://www.amazon.com/Drain-King-345-Bathroom-Condensation/dp/B001ATBS4W/ref=sr_1_1?crid=1XPQUF4EG2GKQ&dib=eyJ2IjoiMSJ9.uLm3RWH9MWVMUZsu2Q2c22HmMTc5gheDH htPzV6mWdbiotlNK16jbW9vmBo9skjVdb71PNcEEycDmgCYyfD qxNyVZkrq1QYAgKbJU84RZFO8BehkcyQy5LMtG7LWD-hbq_E31gdhQjkmtilCYVX3zl1au2bkGVHM-A9Z8fGlG452n-ta-nOxlB6uvAnhH_oGEjEK2cZHNmw86Nhb7H6qNRrLuu8CkhulyXy KBxa2SdtZaXBBKL3d5_A0-clMcJzY1QL8bwbpYxLdQm4fLMFHA66GJJV_FWjM6VuV0SKsXGA .rwdWbCA3BoBfim7-iq0-yXWqVTLUpytbXQ9UQpxbG2Q&dib_tag=se&keywords=drain%2Bking%2B345&qid=1758299530&sprefix=Drain%2Bking%2B345%2Caps%2C184&sr=8-1&th=1)

[Miboater]

I've been doing the hot water flush every two months and for the first time in almost 4 years my system shut down because of a clogged condensate line. Luckily I previosly bought an attachment on Amazon that on one end connects to a shop vac and the other end to the outside condensate line. I procrastinated using it 3 months ago when I bought it but it worked great cleaning out the clog. It was under $9 and it is called AC Drain Line Cleaner Tool Wet Vac Attachment. I was surprised by the gunk that was being sucked out and thinking now that just the regular hot water flush is not enough and will start using vinegar with the hot water.

[Bill14564]

I've been doing the hot water flush every two months and for the first time in almost 4 years my system shut down because of a clogged condensate line. Luckily I previosly bought an attachment on Amazon that on one end connects to a shop vac and the other end to the outside condensate line. I procrastinated using it 3 months ago when I bought it but it worked great cleaning out the clog. It was under $9 and it is called AC Drain Line Cleaner Tool Wet Vac Attachment. I was surprised by the gunk that was being sucked out and thinking now that just the regular hot water flush is not enough and will start using vinegar with the hot water.

When you use the hot water flush are you able to pour quickly? I pour as fast as the funnel I am using can take the water. I have felt pretty good thinking that if water moved that quickly then there must not be a blockage. Maybe I shouldn't be as confident.

[retiredguy123]

I've been doing the hot water flush every two months and for the first time in almost 4 years my system shut down because of a clogged condensate line. Luckily I previosly bought an attachment on Amazon that on one end connects to a shop vac and the other end to the outside condensate line. I procrastinated using it 3 months ago when I bought it but it worked great cleaning out the clog. It was under $9 and it is called AC Drain Line Cleaner Tool Wet Vac Attachment. I was surprised by the gunk that was being sucked out and thinking now that just the regular hot water flush is not enough and will start using vinegar with the hot water.
According to Munn's and Carrier, you should only use hot water in the condensate drain pipe, no vinegar. I use hot water every month, and I also use the device mentioned in Post No. 16 to flush the pipe with water about every 6 months. In 10 years, I have never had a clogged condensate drain.

[ElDiabloJoe]

I have basically the same thing that I bought from Amazon for about $12. It works great.

Amazon.com (https://www.amazon.com/Drain-King-345-Bathroom-Condensation/dp/B001ATBS4W/ref=sr_1_1?crid=1XPQUF4EG2GKQ&dib=eyJ2IjoiMSJ9.uLm3RWH9MWVMUZsu2Q2c22HmMTc5gheDH htPzV6mWdbiotlNK16jbW9vmBo9skjVdb71PNcEEycDmgCYyfD qxNyVZkrq1QYAgKbJU84RZFO8BehkcyQy5LMtG7LWD-hbq_E31gdhQjkmtilCYVX3zl1au2bkGVHM-A9Z8fGlG452n-ta-nOxlB6uvAnhH_oGEjEK2cZHNmw86Nhb7H6qNRrLuu8CkhulyXy KBxa2SdtZaXBBKL3d5_A0-clMcJzY1QL8bwbpYxLdQm4fLMFHA66GJJV_FWjM6VuV0SKsXGA .rwdWbCA3BoBfim7-iq0-yXWqVTLUpytbXQ9UQpxbG2Q&dib_tag=se&keywords=drain%2Bking%2B345&qid=1758299530&sprefix=Drain%2Bking%2B345%2Caps%2C184&sr=8-1&th=1)

Questions about the item you linked: first, what is the difference between the $12 item and whatever else is in the "combo Pak?" Second, when you turn that thing on (the water) and it goes full hose-force doesn't the water hit the block and start shooting back into your face?

Finally, how did you put an on/off valve on it so you didn't have to run back to the spigot?

Thanks

[retiredguy123]

Questions about the item you linked: first, what is the difference between the $12 item and whatever else is in the "combo Pak?" Second, when you turn that thing on (the water) and it goes full hose-force doesn't the water hit the block and start shooting back into your face?

Finally, how did you put an on/off valve on it so you didn't have to run back to the spigot?

Thanks
In the combo pak, you get a separate larger device for larger drain pipes.

I would recommend having a second person to hold the device into the pipe when you first turn on the hose bib. This will prevent the device from popping out of the pipe. Turn on the hose bib slowly. But, once the rubber bladder expands, it seals off the pipe and the water only flows down the drain to flush out the line, with no backflow.

[Miboater]

When you use the hot water flush are you able to pour quickly? I pour as fast as the funnel I am using can take the water. I have felt pretty good thinking that if water moved that quickly then there must not be a blockage. Maybe I shouldn't be as confident.

I was doing the tea kettle and heating the water until it was boiling and then letting it sit for a little while to cool off. It would go down as fast as I could pour it in so I never thought I was having any issues. When I opened the shop vac after I flushed the line there was nothing besides a white and clear slime as I thought maybe a lizard or other varmint crawled in the line.

[Bill14564]

According to Munn's and Carrier, you should only use hot water in the condensate drain pipe, no vinegar. I use hot water every month, and I also use the device mentioned in Post No. 16 to flush the pipe with water about every 6 months. In 10 years, I have never had a clogged condensate drain.

Munn's might suggest something different if hot water alone wasn't solving the problem. Hot water flushes and should kill the bacteria but if that doesn't work then adding vinegar to the water might help.

The blue tablets in the drain tray are supposed to do the job too, just something else to buy.

I don't have the flush attachment and would prefer not to have to use it. If it comes down to it though, every six months isn't bad.

[retiredguy123]

I was doing the tea kettle and heating the water until it was boiling and then letting it sit for a little while to cool off. It would go down as fast as I could pour it in so I never thought I was having any issues. When I opened the shop vac after I flushed the line there was nothing besides a white and clear slime as I thought maybe a lizard or other varmint crawled in the line.
Boiling water is not good. You can damage the plastic pipe or melt the glue and cause a leak. I would only use hot tap water.

[Miboater]

Boiling water is not good. You can damage the plastic pipe or melt the glue and cause a leak. I would only use hot tap water.

I never use boiling water and wait until it cools down to 140 degrees.

[Miboater]

According to Munn's and Carrier, you should only use hot water in the condensate drain pipe, no vinegar. I use hot water every month, and I also use the device mentioned in Post No. 16 to flush the pipe with water about every 6 months. In 10 years, I have never had a clogged condensate drain.

I hear that but I also hear people say they have been using vinegar for years with no issues. I may try the commercial condensate line cleaner that you can get from Home Depot or Lowe's. I believe you use those every 6 months along with the monthly hot water flush.

[retiredguy123]

I never use boiling water and wait until it cools down to 140 degrees.
You are probably safe at 140 degrees for the pipe. That is the maximum operating temperature for PVC pipes. However, I don't know about the glue that holds the joints together. But, definitely do not use boiling water, which some posters have said they use. My tap water is set at 130 degrees.

[jrref]

Folks, just remember, whatever you use to flush your drain, the condensate drain is just PVC going under your air handler, in some cases under your hot water tank and then outside. If you damage or break that drain anywhere under your air handler, you are going to have a very expensive repair.

If you maintain the drain once a month, then hot tap water is all that is needed. If the drain has not been maintained then once it's cleared using a vaccume, then you should be OK. If you are still getting clogs after maintaining once a month then call your HVAC company to see if something else is wrong. If you are a snow bird then maybe one of those automatic systems may be the solution.