Empty Expansion Tank and Glycol all over the driveway

ESH

Hi fellow campers.  Well, I've been enjoying my nicely heated 2021 TAB 400 as a pandemic office this winter but alas, heard some gurgling coming from the glycol tank today (which appeared empty) and found the missing contents on the driveway (appeared to be dripping from the end of a large hose).  I pulled the mattress platform off and didn't see anything leaking or amiss from above.  Is this something that was caused by a build up of pressure or some such, or do I potentially have damaged system?  I am concerned about refilling the tank without knowing what caused it to suddenly drain in the first place.  Any/all advice would be very appreciated.  Also, saw a post regarding some "new" fluid being required by Aldi for units produced 01/04/21 and beyond but assuming that since ours was produced in 2020 we should still use the prior stuff?

Denny16

Sounds like the auto air bleeder valve got stuck open.  There have been several discussions here about this issue.  One was to give the valve a good tap and see if it will close.  The hose under the trailer is the vale discharge hose.
This is the valve in question circled in red:

Sharon_is_SAM

@ESH - I would also check to make sure that the glycol drain plug is still intact.

Denny16

Good point Sharon, he may have lost the drain plug fitting in the hose.
cheers

ChanW

The Alde's glycol drain hose is larger than the others. It's probably ½"id, where the others, like the auto air bleeder that @Denny16 referred to, is probably 3/16"id.

It should have a brass plug in it, with likely some type of hose clamp. (Though the 400 plug might be a bit different)

It doesn't really make sense that it would fall out, especially just sitting in your driveway... but I agree with @Sharon_is_SAM, that's what your description sounds like.

There is no pressure (to speak of) in the system, it's an 'open' system.

ESH

Thanks, all.  I appreciate the insights.  Silly question perhaps, but should the plug be visible from underneath the trailer at the drains, or visible from above? 

ESH

I think I just found a picture from another discussion of what the plug is supposed to look like (red plastic plug).

jimcenname

In my 400 the system drain plug is red and held secure with a hose clamp. The bleeder valve drain hose goes to a ~1' dia port in the floor along with two other clear drain tubes. From the underside the port looks like a large hose. My bleeder failed last weekend after a glycol flush. The glycol is not flowing out of the drain tube, it is dripping. I put a clamp on the bleeder drain hose to keep the fluid in the system until a replacement bleeder valve arrives. 

ESH

Thanks, @jimcenname.  I found the ~1" port on the floor with the bleeder drain hose and 2 clear ones.  I can't seem to locate where the drain plug w/ hose clamp would be.  Would it be on the underside of the port?  I know it sounds like a silly question but I can't seem to locate.  Here is a picture from the bottom and another from the top.

@ESH - Photo resized per Moderator.  https://tab-rv.vanillacommunity.com/discussion/47/what-size-should-my-posted-forum-photos-be#latest

jimcenname

I can't see the drain hose from inside. Outside under the camper behind the wheel a black hose with red plug. 

ScottG

If the 400 is like the 320, there is nothing much to see inside the trailer. The drain is just a molded-in tee that comes out the bottom of one of the glycol heater hoses as it passes along the floor. If you pull up on the hose in that spot it will seem as though the hose is stuck to the floor.

Sharon_is_SAM

That red plug is the Alde glycol drain.  It is intact, so your glycol loss is likely a result of the stuck open bleeder valve which is an easy fix.

ESH

Hi.  The photo of the red plug was from @jimcenname but I checked and mine is also intact.  So, given that the glycol was coming out the drain, seems the issue (fingers crossed) has been narrowed down to the bleeder valve.  When you say it is an easy fix, are you referring to tapping it to try and open, replacing it, or other?  Thanks for the help!

Denny16

If tapping it does not work, you need to replace it, contact nüCamp for the new valve.
cheers

jimcenname

@Sharon_is_SAM, you say the bleeder is easy to replace. Have you done it?

Denny16

Jim, with all the fluid already drained out, take a photo of which hose goes where, or label them.  Remove the hoses from the old valve and put them on the new valve.  Replace the lost fluid and Bob’s your uncle... 
cheers

ESH

So if tapping doesn't do the trick and the valve needs to get replaced, can I clamp the drain hose coming from the bleeder valve as a temporary fix? Obviously the valve is there for a reason, but any danger/disadvantage in clamping for now?

Sharon_is_SAM

@jimcenname - nuCamp replaced ours, but someone else on the forum did it and it was not a big process.
@ESH - I think if you clamp the air hose, you will not be able to vent any air in the system potentially leading to air lock. I would contact nuCamp and ask if this can be done temporarily.  

Sharon_is_SAM

@ESH and @jimcenname - @manny replaced his flow assembly.  Maybe he will chime in.  If you have lost a lot of glycol, it won’t require a lot more to be drained.  Then, you just exchange the flow assembly and refill the glycol reservoir.  Circulate the glycol by running the Alde and add more as air is expelled.  

jimcenname

@ESH, I have no air in my system, I found the leak before the reservoir emptied, I have clamped my bleeder tube. It stopped the leak and the system is working. If you have to then remove air from your system you'll have to do it some other way. I have a manual bleeder in my bathroom. (The 400 had a heater in there.) Truma/Alde recommended I not clamp the bleeder tube but they didn't say why.

pthomas745

Here is the thread where "Manny" replaced his assembly.  Doesn't go into much detail on the replacement, though.

https://tab-rv.vanillacommunity.com/discussion/8940/alde-system-air-vent-valve

cyoung

I just had the same happen to me. Expansion tank empty and glycol everywhere inside on the floor, very messy. I just got it cleaned up and sent a ticket to Nucamp.
Heater has been working great until now. 

Sharon_is_SAM

@cyoung - where did you find the glycol spill?  Is the leak from the over flow hose coming out of the tank or from the flow assembly?

cyoung

Spill  was all over the floor around the Alde heater unit. The brass bleeder valve had some glycol residue around it? 

cyoung

To be a little more specific, there is a short coupling forward of the bleeder valve that has a couple of little clamps on it, this was where there seemed to be some glycol around it. Entire tank was empty and covering the floor around the heater. Glycol was leaking out of the exterior trim. NO spill where the tank is located.

bergger

That's disappointing on a brand new trailer.  Seems to me that there have been more quality control issues with NuCamp lately.  Just based on complaints I've seen on this forum.  With a system as complicated as the Alde (as compared to a normal forced air unit/and traditional hot water heater) I hope NuCamp does a through system check of it prior to shipping the trailers out.  I absolutely know they do not QC their solar systems as mine came from the factory totally wired wrong and I had to figure it out myself, with the help of those on this forum of course! Anyway when they charge such a premium for their trailer and consider it such a step above the average trailer they should do a much better job at testing the systems out in my opinion.  Especially since most of their dealers are not overly familiar with the trailer.  

Sharon_is_SAM

If I remember correctly, there was dried, green glycol residue around the base of the brass valve.  They replaced the entire flow assembly.

ESH

Update:  I clamped the bleeder hose, filled the tank to the "max" line, and restarted the system.  I then tapped the bleeder valve with a hammer a couple of times as suggested, and then removed the clamp to see if the system held.  It is heating now and only a few drops of glycol have dripped out (may have been in the hose prior to tapping on the valve).  

Now the issue is that the expansion tank is showing the fill line well above "max" and pretty close to the top of the tank.  Not sure if I should just let the system settle a bit, or if I should be concerned about it?  Welcome any/all thoughts!

Denny16

I would get a small bit of 1/8th or the next size larger that will fit on the bleeder valve in the Washroom/Toilet Alde heater unit, lay it on the floor and bleed some fluid and air from the system.  Use a jar to catch the fluid with the end of the hose below the fluid.  You start with enough Alde fluid to cover the end the hose, preventing air from being sucked back in.  

Let enough fluid out to get the level back below the max line, slightly higher than midpoint.  This will give enough fluid to re circulate in the system to fill it back up.  Check the fluid level,often for the first few hours of use, and about every 8-10 hours afterwards, to be sure you are above the minimum level.
cheers

cyoung

Well, I found the leak in my hose assembly. The little aluminum pipe with the hose clamps
just forward of the brass valve leaks like a faucet. Went to squeeze the rubber hose and it drips out. Clamps were tight so this is a little odd. At least I know what the problem is and can now tell Nucamp the problem.

Sharon_is_SAM

Can you push the rubber hose into the aluminum?  I don’t remember that much exposed aluminum.