Condensate drain problems

[Dudley do-right]

I 'm having a (built-in) condensate drain problem: And who hasn't had? They are stopped up. foreward and back units.I have found the front drain tube, down the corner of the gen slide-out, but haven't found the back one yet. This by the way, is on my 2007 36FDDS. I've tried putting a small wet/dry vac on the end of the drain, and sucking it clean with mixed results. Haven't done that on back unit because I can't find the end of the drain. I would prefer not to have to dismount the units from the roof (probably best solution) to clean these drains for obvious reasons......anybody got any neat ideas how to open these drains?
Dudley with water dripping off my roof.

[SteveS]

Dudley - I take the cover off the A/C and clean the collection tray and blow out the hose. My rear drain hose comes down the rear end-cap on the driver's side.

[Vtxbiker]

Dudley, I have a 2008 and my rear ac drain is also located on the drivers side rear corner. I recently had my rear ac start leaking on the inside on the bed. I found that the drain tube plastic tray hose connection was cracked and leaked down through the ac cover. I found that you can access the tubes by removing the ac cover. Not easy but can be done. In the end in my case I had to remove the ac unit to replace the drain pans and hoses to fix my problem. After you locate your drain tube you could try to fish a long flexible wire up to clear the tube. Note that the unit has two drain pans per ac unit. The drain lines come to a tee and tie to the main drain line. If the plug is on the pans or the tubes that connect to the tee you will more than likely have to pull the unit to repair.

Hope this helps.

[Refuse1]

Dudley,

Up behind the ceiling AC cover you should find 2 plastic tubes that join at a "T" to a exit hose that carries the condensate water to its exit point outside the coach..

I bought a brass adapter from the hardware store. The adapter allows me to attach a garden hose to the exit hose up in the ceiling and "flush" out the exit hose. The plastic hose that runs from your ceiling to outside the coach will not withstand the full flow or pressure from the garden hose. Just be careful to limit the fresh water flow thru the garden hose to just a small amount.

This should allow you to flush out any debris that may have accumulated in the hose and allow condensate water to flow freely.

On my front AC, I flushed that exit hose and water under slight pressure would flow just fine, but the condensate would not flow. I think there must be a "low spot" in the line somewhere requiring the condensate to "flow uphill". I ended up installing a "condensate pump" which actuates when the AC is running and pumps the water out. Otherwise the water would back up and flow down the side of the coach and make a mess !

[Birddog Pilot]

I'm sure that the methods mentioned to clear the drain tubes work very well, but there is a problem that WRV built into some units. In my case the front drain tube that runs forward from the drain manifold and makes a 90 degree to the left and then down to the overboard line. There is a built in sag that traps water and eventually overflows both drain cups resulting in a lot of water on the roof. Fortunately the AC unit is well sealed or that water would be leaking back into the interior. After many attempts, there seems no way, short of tearing out the ceiling to straighten the sagging line, so I live with it.

[tiredvet]

Originally Posted by Birddog Pilot

I'm sure that the methods mentioned to clear the drain tubes work very well, but there is a problem that WRV built into some units. In my case the front drain tube that runs forward from the drain manifold and makes a 90 degree to the left and then down to the overboard line. There is a built in sag that traps water and eventually overflows both drain cups resulting in a lot of water on the roof. Fortunately the AC unit is well sealed or that water would be leaking back into the interior. After many attempts, there seems no way, short of tearing out the ceiling to straighten the sagging line, so I live with it.

I have blown air into both a/c drain tubes and was able to tell that they are both clear. And yet I still end up with lake Alpine on the roof and then comes the cascading run off just above the entry door.I have to put a little elevation on the front of the coach to avoid the dribble.I'm interested in hearing from those that have solved the issue.

[Old Scout]

Condensation runs off the evap coil into a plastic tray that has two small outlets that dump thru two 1/2 inch holes in the metal housing of the A/C unit. The plasitc cups under the 1/2 inch holes catch the water and drains thru a std plastic [barbed] connector to the plastic tubes previously described. If you are getting water on the roof, my guess is that the catch tray might be cracked, the tray outlets are plugged, or the cups or barbed connectors are leaking.
PS--since the drain cups are above the highest point on the roof, I am not sure why a "low spot" in the drain tubes would cause a blockage--curious minds need to know?
PSS--just to be clear, the condensor coil doesnt have a catch tray so melt water from a heat pump defrost cycle will drain on to the roof....

[ralph0808]

I have in the past put that good old bleach in my AC drain pipes in the stick n brick homes. It will help clean out the green slime n crud from the inside the lines. Maybe adjusting the jacks just a little up or down would help drain lake Alpine off the roof also. Good luck, I haven't had drainage problems yet but my AC's are running hard as I type this. Maybe I should add the pipes clean out as a yearly or quarterly maintenance item.


2005 Alpine 40 FDQS

Ralph

[Refuse1]

As mentioned above, my front AC drain line flows freely with a slight amount of pressure, but will not drain via gravity. I think there is a low spot somewhere. I plumbed in a condensate pump that is normally used with wall mounted home or business AC units. I chose the Refco Sahara because of its small size. It has a little mini reservoir that actuates the pump when condensate is present. I had to do some plumbing work to adapt the input & output hoses to the ones in the Alpine, but once installed it works like a champ.

Here's a link to the manufacturer web page: Condensate Pumps

[Birddog Pilot]

Old Scout,
I went through the drill of making sure that the plastic tray was okay, the drain cups secure, put the air hose on the drain lines to check the air coming out at the cups and all was good. Guaranty in Junction City, Cummins Coach Care in El Cajon, CA, and Coburg, OR were stumped as to why, with the system tight, the water would still overfill the drain cups and end up on the roof. On one visit to Guaranty I talked with another Alpine owner also there for maintenance, not the condensate problem, and they said that WRV was known to have created low areas in some of their air conditioning drain line installations as they passed through the ceilings of some coaches. A few years later while Scott and Bobby were re-doing the AV system I mentioned the air conditioning water never draining from the front unit. The entire front cabinet area was open and the line running down the left side windshield post was visible. Putting water into the drain cups and then pulling on that overboard drain line would straighten the tubing somewhere in the ceiling removing the probable downward bow which had created a low spot trapping the condensate and a little water would dribble out, but nothing like the flow of the rear unit.


I have tried pulling on the vertical portion of the overboard line (the only line visible without tearing out the ceiling) and attempting to clamp it to put pressure to straighten the line, but that produced little results.


Refuse1, it looks like you might have hit upon a fix to the problem; it's too bad we have to re-engineer something as simple as an air conditioning drain line.

[Old Scout]

Dick--I try to stay away from using "never" or "always" but the laws of gravity are pretty hard to overcome--as long as the collection cups are the high-point in the system, "low points" along the route shouldnt matter. Still sounds to me like there must be a kink in the line that flexes open under air/water pressure [flushing] but doesnt allow for gravity flow. Perhaps the "mini" pump is your answer.....

[Dudley do-right]

Many thanks to all who replied...
Upon removing the cover to my A/C unit, I found the streetside drain cup full and overflowing. Next I removed the housing cover over the evap/blower assembly, looking for blockage in primary drain pan. Clean, but only draining out streetside opening. Bus was level, ergo, A/C unit not level. I drew down on curbside anchor bolts until getting water draining to both secondary drain cups. I think the drain line from the streetside cup was stopped up though, so I fished a wire through that side to across to the tee. Now both sides drain more or less equally, and no more water on roof. Upon successful completion of this job, I promptly fell off of the roof.I am bloody but unbowed.
PS.... having worked in the HVAC industry for many years, I can tell you that a bow in a condensate line will cause flow to stop. I'm not sure why, but it will.
THANKS TO ALL who contributed, the tip about the mini condensate is a good one. I printed it out to save; you never know when something like that will come in handy...especially with a baulky cond. drain.
Dudley

[Old Scout]

OK--I didnt know Newton personally but if a low point in a line will stop the flow--then the p-traps in my sinks, my toilets and the condensation drain on my home A/C unit wouldnt work---hum???????? If the input source is higher, its gotta work....any debris notwithstanding.....

[tiredvet]

Originally Posted by dudley do-ri

Many thanks to all who replied...
Upon removing the cover to my A/C unit, I found the streetside drain cup full and overflowing. Next I removed the housing cover over the evap/blower assembly, looking for blockage in primary drain pan. Clean, but only draining out streetside opening. Bus was level, ergo, A/C unit not level. I drew down on curbside anchor bolts until getting water draining to both secondary drain cups. I think the drain line from the streetside cup was stopped up though, so I fished a wire through that side to across to the tee. Now both sides drain more or less equally, and no more water on roof. Upon successful completion of this job, I promptly fell off of the roof.I am bloody but unbowed.
PS.... having worked in the HVAC industry for many years, I can tell you that a bow in a condensate line will cause flow to stop. I'm not sure why, but it will.
THANKS TO ALL who contributed, the tip about the mini condensate is a good one. I printed it out to save; you never know when something like that will come in handy...especially with a baulky cond. drain.
Dudley

I'll have to check the level on my a/c units. Glad to hear your project had a better ending than what you had .A fall from the roof would end most folks RVing days.