Air conditioner drain lines plugged?

[Jim]

I was up early and heard a small drip, drip, drip. Found it coming out of the small, disk light above the passenger seat. There's an air conditioner on the roof, just above this light, and I think the drain lines coming from the pan that the conditioner sits may be clogged, and the water is coming over the sides and then down into the coach.

So when the sun came up, I looked at the lines. There is condensation coming out both of them, just not as much as I would expect.

Drivers side has what appears to be unrestricted flow.
Passenger side, not so much.

I took a shop vac and tried to blow the lines out. But the lines just don't seem to be clear at least it seems that way because the air isn't flowing like I would have expected.

So the question is, should I put some serious air pressure through the lines? Or do they terminate somewhere different that where I think they do, and the added air pressure might do more harm than good?

2016 London Aire

Picture 1 Drain line Drivers side
Picture 2 Drain line Passenger side

 

[CaptainGizmo]

Jim,

I can tell you our Newell’s system and diagnosis; hoping it gives you direction.

Units like the Mach8 have a pump and float in the pan that can malfunction. As a routine check, we have to pull the access panel off from INSIDE the coach, where you can see if it’s working.

We have a sight tube inline on the drain line and we use a water bottle with a sharply bent straw (like football players use with their helmet on) to squirt water into the drain tray. When the AC is running that float and pump should work intermittently to purge the water out. If not, then we can take that sight glass off and blow the line with compressed air.

 

[Jim]

I believe you nailed it @CaptainGizmo ! And it appears the pump has decided it was time to leave us.

Thank you for the reply.

 

[Jim]

Quite sure the pump is the problem. The drivers side it working well, lots of water coming out the drain tube. The passenger side is not working at all.

It's way to hot to climb up on top of the rig right now, so I've turned off the front air conditioner and let the other two handle the cooling. Might have to turn the front back on intermittently as it's hitting high 90's here today. But we'll see how it goes.

Thanks again, @CaptainGizmo

 

[CaptainGizmo]

Quite sure the pump is the problem. The drivers side it working well, lots of water coming out the drain tube. The passenger side is not working at all.

It's way to hot to climb up on top of the rig right now, so I've turned off the front air conditioner and let the other two handle the cooling. Might have to turn the front back on intermittently as it's hitting high 90's here today. But we'll see how it goes.

Thanks again, @CaptainGizmo

Jim,

Just so ya know…I was surprised to find out the drain pan AND pump/float can be accessed from UNDER the AC unit INSIDE the coach! Hope that keeps you out of the heat.

 

[redbaron]

Jim: Newmar doesn’t use mach8 or a pump. The drains you have are roof drains.

I would start with less than 30psi of opreasure to work loose, ***BUT*** none of this explains water in the ceiling.

That’s a separate issue.

My guess is you have a failure of a seam caulk or dicor around a roof intrusion. You need to inspect that.

The alternate problem is a failure of the pex line which is a joint in the roof, but that does not go over the area you indicated.

Check the roof first.

 

[CaptainGizmo]

Jim: Newmar doesn’t use mach8 or a pump. The drains you have are roof drains.

I would start with less than 30psi of opreasure to work loose, ***BUT*** none of this explains water in the ceiling.

That’s a separate issue.

My guess is you have a failure of a seam caulk or dicor around a roof intrusion. You need to inspect that.

The alternate problem is a failure of the pex line which is a joint in the roof, but that does not go over the area you indicated.

Check the roof first.

Thanks for the clarification, Ronnie...I couldn't remember my Dutch Star's config, so I took a stab at it.

I've asked if blowing from the "bottom end" was a good idea but...for the reasons above...not necessarily good. They've said, "Easy...but may end up making your day worse if there's a blockage and you blow a line apart or blow water where it shouldn't be."

So, I did it anyways...LOL...I love to live on the edge.

 

[redbaron]

I do blow on mine to clear the lines. Never more than 30psi. Usually just a small hand pump sprayer that’s empty. That’s usually enough air to loosen and allow it to drain.

 

[lostinfla]

I just use a water hose to clear my roof drains. Squirt a little water up the line and the vacuum as it comes out usually clears the line. I also extended the drains to come out the bottom of the coach for easier access and visible confirmation that they are not clogged. Pics of rear, but I also did the front.

 

[Neemer]

@lostinfla I like that. Good idea. I’m stealing it.