T@B 400 Alde corrosion

pthomas745

If you think the bleed valve is defective, it would have ejected the glycol out under the trailer. This would be very obvious under the trailer. Since you recently emptied and filled your system, it may just be their is/was still some areas in the glycol loop that still had a little air, and the Alde "burped" that air from the expansion tank.

So....how much glycol is under the trailer?  How much is in the expansion tank? I would try adding glycol into the tank and observing the valve and the drain.

If you saw the other threads about failed valves.....a lot of glycol was spilled in those cases.

In the DIY Glycol Change file, the whole last section describes "burping" the Alde and adjusting the amount of glycol in the tank as air is ejected.

barbarella20722

@pthomas745 I was around the back of the trailer yesterday morning and didn't see anything. So my assumption is it started 'leaking' late afternoon or evening. I checked the tank when I noticed (8 pm?). There was about 2" visible. This morning (6 am) it was down into the plastic tube areas. I filled it since some indicated that you shouldn't leave it that low. I'm not exactly sure how much is a lot, but it doesn't seem excessive, given it's been more than 12 hours since I noticed a leak. I'll look for the "burping" thread. Then empty the bucket, run the Alde and see what I can see. 


I took these a few minutes ago. 


From this morning around 8:30.

pthomas745

Thanks, I did not notice the bucket before!  How much is in it?  You mentioned one pump turned up high.  The glycol can escape from the tank from that tube that comes from the top of the tank.  It drains, along with the air bleed valve drain, from that "plug" in the Alde compartment floor.  The expansion tank tube is clear, and it will be easy to tell if there is glycol in it.

Sharon_is_SAM

Not sure which pump is for the main Alde and which for the flow, but I think the 400 setting is typically set at 2-3.  Can any 400 owner confirm?

Bill&Suze

Sharon_is_SAM said:

Not sure which pump is for the main Alde and which for the flow, but I think the 400 setting is typically set at 2-3.  Can any 400 owner confirm?

I just tried to get good photos of the two pumps on our 2024 400 but I'll admit that it is difficult to do, given the tight constraints of all the plumbing down there. No way that I could actually get eyes on them. The rear pump at the Flow appears to be set at 4 and the front at 2.

barbarella20722

@pthomas745 my bucket collection is limited to Menards green. So it's difficult to see the glycol. I ran the Alde for about 15 minutes before it got too warm to keep hiking the thermostat set temp. No dripping then and the clear tube was dry. As far as I can tell, it's only coming from the black hose (not the drain/red stopper). I've been out but will check the bucket when get back. 

barbarella20722

@Sharon_is_SAM I set them both at 2. I have no idea what the rear one was set at to begin with. Embarrassed to admit that I didn't realize there was a second pump until I removed the convectors for repairs a few weeks ago.

fstop32

@barbarella20722, just saw your post...out of an abundance of caution I replaced mine when I rebuilt my system...so far no runs drips or errors.

qhumberd

Bill&Suze said:

Sharon_is_SAM said:

Not sure which pump is for the main Alde and which for the flow, but I think the 400 setting is typically set at 2-3.  Can any 400 owner confirm?

I just tried to get good photos of the two pumps on our 2024 400 but I'll admit that it is difficult to do, given the tight constraints of all the plumbing down there. No way that I could actually get eyes on them. The rear pump at the Flow appears to be set at 4 and the front at 2.

So on our 2019 that has the 3020 and the Flow unit there are two pumps as described. When I did my flush I was puzzled until I realized that the rear most pump going to the Flow unit does not run unless the control panel calls for max hot water, and then only for 30 minutes. During this time the main pump (near the boiler) stops running, even if set to CONT. All other times the main pump is all that runs when it calls for heat or hot water.

I believe that normal operation both should be 2-3 setting. That works for mine. If the pump is set higher than 4 it causes a lot of churning which I believe could increase pressure and cause the overflow to happen.

barbarella20722

@qhumberd thank you for this. Mine is also the 3020. So I'm going to assume that it will function the same or similar. 

barbarella20722

@fstop32i I don't blame you for replacing it as a precaution. I just checked the bucket and there is a tiny bit of glycol. Not sure if it's residue from when I emptied it. I'll check it again in the morning.

  Was the automatic bleeder difficult to replace? I was wondering where that little black hose goes and if I have the skill to reinstall it properly?

pthomas745

The bleeder valve itself is not too hard.  Are you talking about the "little black hose" that drops into the "plug" on the floor of the Alde compartment?  Those hoses mostly just "push" in to the holes in the plug.

barbarella20722

@pthomas745 yes, that's the one. I haven't traced it yet. It's like spaghetti in there. I think I just keep hoping I didn't bleed the system thoroughly enough and it was just finishing the job.

Edit: checked the bucket this morning (6 am). No more glycol seems to have been released. Weird.🤷

fstop32

On my T@b there is a larger, probably 1-1/4" rubber plug in the floor with 3 smaller holes in it.  The small rubber hose from the bleeder simply sticks into one of the 3 holes and extends maybe an inch below the floor.

barbarella20722

@fstop32 thank you! So far, there's been no my glycol in the bucket. So fingers crossed I'm done with this for a while. But I'll know about the valve in case it fails in the future.