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Unico AC not draining properly....
wcweaver3
Member Posts: 51
Hi -
I have a Unico AC system (MC3642C) in my second floor bedroom closet. The cooling unit sits on top of a fan box. Both the cooling unit and the fan box have PVC drains. The two PVC pipes come together and create a main PVC drain line behind a knee wall and then travel the length of the living room ceiling and to the outside. I noticed a slight drip around one of the ceiling ducts and a technician came and blew out the PVC line with compressed nitorgen and said all good. About 5 hours later, gallons of water poured through the living room ceiling. When that chaos occured, I disassembed the PVC pipe from the main cooling module and now have it draining, via a funnel, into a bucket. It would drain continously at about a gallon an hour and I'd just empty it no problem. A second technician came a day later, crawled behind the knee wall via a small access door and showed me pictures of a shattered main PCV line right where the water came out of the ceiling. Of course, that has to be replaced. I noticed however, that the second drain line, the one coming out of the fan box below the cooling unit, was still connected and if water came out of that it would go into the the main PVC line which was now shattered behind the knee wall. Not wanting a repeat of that chaos, I asked the technician to cut that second PVC coming out of the fan box and direct that to the bucket, which he did. The second technician also opened the cooling module to inspect the coil but only saw a few drips and all seemed OK.
Here's the problem - ever since the second technician left, the cooling module will only drain the moment it is turned off. As an example: Previosly, the cooling unit would dribble water continously into the bucket at about a gallon an hour and the water will start maybe 5 minutes after the cooling unit kicked on. Now, I'll run the cooling unit and when the unit is running for even half an hour or more, there is not a drop of water draining. Then, the moment I turn it off, a steady stream of water comes out of the cooling unit into the bucket - about the same amount as I would expect as if it was draining continously as before. I thought that the technician may have disrupted some type of air flow or vacuum by cutting the second PVC line coming out of the fan box, so I reconnected it with some tape, but it didn't have any effect. My concern is that if the cooling module doesn't drain until after it's turned off, then maybe there will be some condition where it will overflow onto the closet floor and then I have a second episode of chaos. Of course, I have to get the main line repaired, but any thoughts as to how to get the cooling unit back to draining continously into the bucket as before? Any help is most appreciated - thank you!!!
I have a Unico AC system (MC3642C) in my second floor bedroom closet. The cooling unit sits on top of a fan box. Both the cooling unit and the fan box have PVC drains. The two PVC pipes come together and create a main PVC drain line behind a knee wall and then travel the length of the living room ceiling and to the outside. I noticed a slight drip around one of the ceiling ducts and a technician came and blew out the PVC line with compressed nitorgen and said all good. About 5 hours later, gallons of water poured through the living room ceiling. When that chaos occured, I disassembed the PVC pipe from the main cooling module and now have it draining, via a funnel, into a bucket. It would drain continously at about a gallon an hour and I'd just empty it no problem. A second technician came a day later, crawled behind the knee wall via a small access door and showed me pictures of a shattered main PCV line right where the water came out of the ceiling. Of course, that has to be replaced. I noticed however, that the second drain line, the one coming out of the fan box below the cooling unit, was still connected and if water came out of that it would go into the the main PVC line which was now shattered behind the knee wall. Not wanting a repeat of that chaos, I asked the technician to cut that second PVC coming out of the fan box and direct that to the bucket, which he did. The second technician also opened the cooling module to inspect the coil but only saw a few drips and all seemed OK.
Here's the problem - ever since the second technician left, the cooling module will only drain the moment it is turned off. As an example: Previosly, the cooling unit would dribble water continously into the bucket at about a gallon an hour and the water will start maybe 5 minutes after the cooling unit kicked on. Now, I'll run the cooling unit and when the unit is running for even half an hour or more, there is not a drop of water draining. Then, the moment I turn it off, a steady stream of water comes out of the cooling unit into the bucket - about the same amount as I would expect as if it was draining continously as before. I thought that the technician may have disrupted some type of air flow or vacuum by cutting the second PVC line coming out of the fan box, so I reconnected it with some tape, but it didn't have any effect. My concern is that if the cooling module doesn't drain until after it's turned off, then maybe there will be some condition where it will overflow onto the closet floor and then I have a second episode of chaos. Of course, I have to get the main line repaired, but any thoughts as to how to get the cooling unit back to draining continously into the bucket as before? Any help is most appreciated - thank you!!!
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Comments
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Can you post pictures of this?
Cooling unit sits on top of a fan box? Thats strange!0 -
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Picutre posted!
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you need to have a Ptrap on that. the negative pressure generated by the fan is keeping the condensate suspended until the fan turns off.
https://www.youtube.com/watch?v=uB_3NbvH754
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If the evaporator is on top and the blower compartment is on the bottom, the top drain doesn't need to be trapped, and I have no idea what the bottom drain is for. Does the bottom drain continue internally to the evaporator condensate pan?
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is it set up as a down flow configuration. unit set up should have blower compartment downstream of an coils, what we call a "draw thru" configuration.0
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It's a self contained , Condo ? You need a trap....
There was an error rendering this rich post.
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Hi All - thanks for the thoughtful comments. The lower drain goes comes out of the fan box and apparently is a secondary drain in the event the primary drain clogs up and the cooling box overflows. The fan box also includes a Hartell Safety Switch so if there is a lot of water there, it will shut down everything. Marco7 posted a video about P-traps and I installed one and it works well! Thank you! It still drains into the bucket that I have empty periodically, but that's OK until the HVAC people can get here to repair the damaged line. Many thanks to everyone - your comments were really helpful in trying to figure this one out.
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BTW - this is a Unico system installed in a second floor bedroom closet of a home built in 1940 which was never designed for AC.
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Make sure the new line is pitched so that it drains, so it doesn't hold water. The broken line is very likely from it holding water over winter and freezing.0
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If the condensate line is not pitched going out of house , it could freeze during the winter and break it up . To get the pitch it is best to run right out of the house .
There was an error rendering this rich post.
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