Found a fix for "No Alde heat" when all fuses are good

Tabaz

Chan - thanks for your suggestion about that resettable fuse.  I ordered the exact one you specified above and will return the others to Amazon.

ChanW

@Tabaz , I didn't find a resettable fuse, all I found was a replacement just like the original.

Looks like I misunderstood your earlier question. I thought you wanted the part number for the exact replacement.

Sorry about that!

Tabaz

I did ask for the original part.  My tech friend recommended the resettable type after clicking on your link.

Tabaz

My tech buddy devised this emergency fix in case that F-2 fuse blows.  The fuse was soldered to the two alligator clips at the center and then a section of heat shrink was applied over the fuse and connections.

Bayliss

I like that idea, @Tabaz.  A simple solution.

sbutzen

ChrisK said:

Finally had a chance to look in to fixing this. A stent caused a stint in the hospital first. 
OK, so on to the repair. Like I said above, through testing, I determined the problem was probably the thermal fuse. Today, I found one of my jumper wires and bypassed the fuse and the Alde came right on (yes, I had reconnected it all first). Yup, bad fuse.



First step was to remove the board. Sorry, forgot to get pics of this. Pretty easy though. Remove the cover and 2 screws hold the plastic board cover on. Unplug all the connectors up top. Take pics of them so you know what goes back where. There are 3 more connectors at the lower right part of the board (you can kind of see them in the second pic below). ChanW mentioned you have to have small hands to reach them but like he said, once you free the board from the housing, pull the board up and then unplug these then. Mark these 3 lower connectors well. 2 of them look identical and can be plugged in to each others' socket. I marked one with a silver sharpie as well as its location on the board. **Note** in the first pic, immediately below, there are 5 wires but there are 7 places they can plug in to. Note where you unplugged them from.





There are 3 plastic clips (2 on the right and 1 on the left as you are looking at the board) and 1 screw on the left side holding the board in. The screw is hard to get to but an extension from a ratchet and the proper torx bit had it out in no time. Yup, the cover for the board and the board itself are held in by Torx screws, not the usual square screws. Slide the board out and unplug the lower 3 plugs. I know this isn't a common failure fuse but I didn't want to go through all this again so I went with a similarly rated replaceable thermal fuse (noted in one of the posts above) so it was time for a little reworking. I clipped out the old fuse bu kept its "pigtails". I removed them from the board and soldered these to some wires that will go to the replaceable fuse. 

This is the old fuse still in place.



Clipped



Wires soldered on to the pigtails. I did this to make soldering them to the board easier. Yes, I did put heatshrink on the connection. Even though it looks like I just soldered the wire to the side of the pigtail, they were folded over each other before soldering. More secure connection.



Soldered to the board



And routed, connectors installed and the new thermal fuse attached with Magic Tape. I did have to clearance the plastic housing a bit allow it to go back in place with the wires there. I thought about putting heatshrink over the connectors but there is almost 0 percent chance of something getting in there to short them out. 



And the final result!



This really wasn't that difficult to do. Had I just replaced the thermal fuse with the same thing (I bought some of those too in case the replaceable one didn't work), it would have been even shorter. I wouldn't have removed the board completely, just leaned it forward to access the solder joint on the back side. Like I said in my post above, I think these things just wear out over time and eventually fail. It is not indicative of a true fault but a component that got faulty over time. I have the camper on to test it overnight to make sure it stays on. 

Thanks for this ChrisK.  I'm going to solder in some lead wires too and use crimp connectors for the actual fuse.

fstop32

I'd read this thread before and thought "maybe my 2015 won't have this problem"...no such luck, mine apparently popped while sitting on my carport.  I discovered it while prepping for an upcoming trip.  I had picked up the tip on the alligator clip temp solution and made up the very jumper cable "just in case".  I pulled the jumper out of my T@b electrical box of goodies and clipping it in place immediately had the Alde working.

I didn't want to take my trip using the alligator clip and I wanted to solve the issue in a way that would allow "relatively easy" change out of that fuse while on the road.  Here's what I came up with and if anyone sees a problem with my solution please let me know!

I used 2 Wago lever operated wire connectors.  I clipped the existing leads right next to the bad fuse leaving the leads in place on the board.  That left one lead too short to work with effectively so I added a bit of solid wire to that lead and soldered in place (with an appropriate heat sink between it and the board).
   

I then bent the leads on the new fuse and clipped it in place on the Wago's.  The first pic below has the new jumper shown upside down from how it actually mounts, I just wanted to show what it looked like before placement.  The second one below shows it in place, the third a top view
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I had to relieve the lower plastic plate a bit to accommodate the size of the Wago's.  I first carefully peeled up the diagram and placed it lower so I wouldn't cut into it.  Then trimmed the plastic.

    

All the wiring harnesses plug in normally with no clearance issues.  The release levers on the Wago are pointed down (that's just the way this design works) so to replace this fuse requires take down to the point of removing the plastic plate.  This is a bit of a chore but the biggest issue is unscrewing the seat back to get full access to my Alde!  I'm working on a custom tool that will allow me to flip the levers without having to go that deep .

Not sure what it's actually worth but this setup mounts the fuse almost exactly where the original fuse was placed and hopefully means it will receive the same access to the heat it is designed to monitor.

Please feel free to enlighten me to any negative issues I might have exposed myself to! 

ChanW

Nice use of wago connectors! I just might have to use your idea!

I'm surprised that you need to remove the seat back to get the cover off the Alde. For me, it was tight, but not impossible. I do remember the seat-back has to be in a specific position to get the cover off, can't remember what that position was though! 

Thanks for writing it up! 

fstop32

@ChanW, I suspect that when I totally rebuilt the Alde system (except the boiler) and while waiting on parts I rebuilt almost all of the bench framing and added some electrical junction boxes.  In doing so I think the boiler got shifted slightly toward the rear and that's why I no longer have "easy access" to that top panel on the Alde.  Fortunately I don't have to remove the bench back, just unscrew it and slide it a couple of inches to the rear.