Air Conditioning - Primary condensation line problems
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rbm7971
08-03-04, 10:32 PM
A couple of weeks ago we noticed water dripping outside from our secondary condensation line. Went up in the attic and saw that the drain pan below the A/C unit had water; assumed primary line (which runs to the bathroom plumbing) needed unclogged. Serviceman came and cut the primary line open, blew it out with air compressor, but inside of line appeared to be clean. We continue to have the problem, though. The main line fills with water, and water then trickles very steadily into the drain pan below the unit....leading to a constant and steady dripping outside. I can blow into the main line and the water temporarily clears, but it soon fills again. Is it likely that the main line did not get properly cleared? Or could the unit be producing too much water for the main line to handle?
bigjohn
08-04-04, 04:45 AM
My thoughts on this:
1. Are you sure it's the drain line backing up and it's not water running out of the unit itself because the drain pan inside the unit at the cooing coil needs cleaning?
2. Is the drain line pitched in the directon of flow with no sags and is it trapped?
3. On residential units the drain line is normally 3/4" PVC pipe. If you have a 1/2" drain line that would be undersized- IMHO.
4. You're saying that the drain line runs into the bathroom plumbing. What does this mean exactly? Does it run into the stack? It's much better to have it free flow to the outside of the house.
1. Are you sure it's the drain line backing up and it's not water running out of the unit itself because the drain pan inside the unit at the cooing coil needs cleaning?
2. Is the drain line pitched in the directon of flow with no sags and is it trapped?
3. On residential units the drain line is normally 3/4" PVC pipe. If you have a 1/2" drain line that would be undersized- IMHO.
4. You're saying that the drain line runs into the bathroom plumbing. What does this mean exactly? Does it run into the stack? It's much better to have it free flow to the outside of the house.
rbm7971
08-04-04, 06:08 AM
Thanks for the response and the thoughts. I had seen the suggestion to check the drain pan in the unit on some other posts; I'll take a look tonight. But even when the unit's not running, water sits in the primary line and does not drain (I can see in it at the "T" in the PVC after the trap). That makes me wonder if there's something downline still prohibiting flow?
The pitch wasn't great before, but is much better now (since the serviceman came out to clear it and adjusted the pitch), with no sags. It is trapped, and it is 3/4".
Not sure exactly what you mean by stack, but the primary line comes through the bathroom wall under the sink and feeds into the vertical pipe coming from the faucet. Sounds like free flow would be better and might be the problem...but given the current design is there anything I can do?
The pitch wasn't great before, but is much better now (since the serviceman came out to clear it and adjusted the pitch), with no sags. It is trapped, and it is 3/4".
Not sure exactly what you mean by stack, but the primary line comes through the bathroom wall under the sink and feeds into the vertical pipe coming from the faucet. Sounds like free flow would be better and might be the problem...but given the current design is there anything I can do?