Aquahot AHE-100-02s leaking coolant at filler neck

[joefromperry]

I have my aquahot pulled out of my 2003 signature because of a coolant leak that I couldn't find; what a pain. Anyway, with the boiler full of regular water and both manifold valves turned off, I pressurized the system through first the overflow with regular cap on to around 13 lbs, and then again with a mity-vac radiator cap pressure adapter. I had some leakage around the filler neck. I heated the neck with a propane torch, and the top just came off easily with no persuasion. I was surprised to see there's only maybe 1/8 inch of overlap for the solder. So, I cleaned both surfaces very well, thinking it'll be easy to resolder. However, I must be missing something, because the top will not solder to the neck. Dissimilar metals? Probably going to head to my radiator shop to see if he can do anything, bur first, any suggestions?

[vito.a]

This is a common issue.  They make replacement filler necks for it.  One of the versions clamps on and the other solder on.  

Contact John Carrillo:  About John Carrillo - Hydronic Heating System Specialist (heatmyrv.com)

Or Roger Berke:  No-Solder-Filler Neck Kit (rvhydronicheaterrepair.com)

Edited August 22, 2021 by vito.a

[Poohbear]

On 8/22/2021 at 5:19 PM, joefromperry said:

I have my aquahot pulled out of my 2003 signature because of a coolant leak that I couldn't find; what a pain. Anyway, with the boiler full of regular water and both manifold valves turned off, I pressurized the system through first the overflow with regular cap on to around 13 lbs, and then again with a mity-vac radiator cap pressure adapter. I had some leakage around the filler neck. I heated the neck with a propane torch, and the top just came off easily with no persuasion. I was surprised to see there's only maybe 1/8 inch of overlap for the solder. So, I cleaned both surfaces very well, thinking it'll be easy to resolder. However, I must be missing something, because the top will not solder to the neck. Dissimilar metals? Probably going to head to my radiator shop to see if he can do anything, bur first, any suggestions?

 One is doing the exact same thing , been wanting to pull it out but have been putting it off. 

[Ivan K]

If you have not done it yet, search this forum and see the few different ways of how some of us have solved the leaky neck in somewhat unorthodox ways without removing the AH. I have had the pleasure of removing and reinstalling the box before the neck started to leak and would not do it again just for that.

[joefromperry]

Thanks for the replies. Here's an update. My radiator guy fastened the filler neck / radiator cap area  with silver solder. No leaks. I then replaced the check valves, as they were less than $7 each at Menards. My final quest is to replace the brushes on the circulation pumps, as on the one pump that wasn't working when I pulled the brushes, there was nothing left, only the spring. I found a place that is open on Saturday and only an hour away, so tomorrow I'll get them, fix the pumps, and try to get it all back together.

 

[Guest old5foot]

Joe, I am having the same issue. Did you watch your radiator mechanic do the fix?

The neck on the fill/overflow tube on my unit barely comes above the case. Did your guy have to remove the case?  Looks like mine is riveted.

Also did he have to disconnect the fill/supply hoses to get the top off.

Just looking for background info. to communicate with the tech.

Thanks 

Old5foot

 

 

 

[Paul J A]

Roger Berke @ http://rvhydronicheaterrepair.com/  has a modification/repair for those neck issues. 

He is an expert. You should consider joining his forum. 

[joefromperry]

Hi, Old. I had removed the unit from the coach, and then opened / removed the case. I pressure tested the unit then, and that's when I saw it leaked from the neck. The filler top came off pretty easily, as there was hardly any solder there. I couldn't fix it, and that's when I took it in to my radiator guy, who silver-soldered it back on. I concur with Paul's suggestion to join the above forum, although Roger was absolutely no help to me. He does have a non-solder replacement for the filler top, if you don't want to pull the whole thing out, but it's around $240. Let me know if I can answer any more questions.

By the way, I have it all reinstalled and everything works as it should. I did have to replace the whole exhaust, as it was so rusted that it broke during removal. I had a muffler shop bend me a new piece; I heat-wrapped it and installed it.

 

Edited September 12, 2021 by joefromperry

[Guest old5foot]

Thanks for the info. Joe. I nipped the end of the surge tank supply hose and reconnected it. So far so good.  Figured a 16 year old connection might be the problem and it seems to be.

 Rogers $240 sounds reasonable if it can be done while the unit is in place.  Appreciate the update.