during my recent Aquahot burner service, I opened my enclosure to find a bit of coolant in the pan under my blower. First thoughts were winterization went wrong, but luckily found it instead to be an age or abuse related stress crack on the engine recirculation piping.
As what I found I feel could maybe happen to anyone, figured I would photo and share.
The coolant leak was emminating from the copper "L" just right of a copper union that is in place to facilitate the recirc pump replacement. I myself have never been a big fan of copper unions, as all it takes is one slip when loosening/tightening to stress the mated pipes. Is that maybe what happend here.....OR was it the weight of the pump assembly over time, it is quite heavy? only the tootsie pop owl will ever know.
You can clearly see the stress crack. I would add the copper used OE was the heavier type N thick wall. It takes quite a bit to create a stress in that stuff.
As I am not a fan of unions, I chose to use compression fittings in place. Local lowes only had one compression fitting in the size I needed, so I opted to use Sharkbite fittings for the rest. They are rates to 200psi and 200°F. I may upgrade them to comp type if I see any heat related issues. The hardest part about the job was getting the downpipe cut for the placement of the new fittings. With the compression fitting in the place I put it, it is also quite easier to remove the pump for service or replacement without extra stress on the piping system. I also added a piece of 3/8 polycarbonate under the pump so its weight does not affect the piping.
On the left upper corner of your first picture it looks like your zone pump seal might be leaking. I replaced all of the pump seals and had to drain the Aqua Hot to accomplish the project. I will have a close look at the copper tubing as I am pulling the burner for service and a new igniter coil next week.
Good point did not notice that with all the attention on the problem I encountered while doing a basic burner service. Do you by chance have the part numbers for the seals? I'll go ahead and do all those while in here!
And if I am going to do that might as well replace that recirc pump that is also not working....gotta see can I spec that.
I will look for the post, I got the numbers from a member at the time.
Found the post. Look at reply #14 and #19
Aqua Hot Repair (https://www.foreforums.com/index.php?topic=32190.msg287132#msg287132)
Thank you. Need to be sure what type of Zone pumps I have....as for the engine recirc pump that I feel will be the entire pump, not to include the brass base....based on the parts manual, looks like all of those pumps are the same.
The seals were the same on all 4 pumps on mine.
In 2019 we traveled from CA via Nac then Blue Ox in NE to HWH in IA on our way to a RV Fantasy caravan to the Canadian maritimes. While in ME I discovered a similar leak, but on the other side of the AquaHot. The crack was on the outside of the elbow. Bought a piece of coolant hose to bypass the AH. Completed our caravan trip and stopped by FOT for maintenance on our way west. I had FOT replace the 90 degree fitting and all was well for about 6 months, then the elbow fitting shown in your post cracked on the outside bend. Found my old coolant hose part to yet again bypass the engine loop. The AH tech from AR said he would have to remove the unit to repair the pipe. Currently it still needs repair. May take your approach when I get my transmission issues resolved.
Seems to be a very common occurance on these AquaHots, especially the twenty+ year old ones. PO of my coach used some sort of putty to fix a leak on the rear engine line and then a few months into ownership, the front one started to leak. I ended up cutting out the elbows and used high temperature silicone coupler hose. I found this route from someone else either on foreforums or another site.. it's been about 9 months and they are still holding up just fine.
Amazon.com: HPS HTSEC90-062-BLUE Silicone High Temperature 4-ply Reinforced... (https://www.amazon.com/gp/product/B004OZ8LX0/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1)
You can purchase heater hose with a molded elbow from auto parts stores. Cut the ends to the length yu need. Remove the elbow and install the molded elbow and double clamp. No need to remove heater from coach.
Like Rudy said. I had repaired several using compression fittings, but the last one I decided to use heater hose and found a 90 degree hose and double clamped it. Wish I had thought of that sooner. It was much easier and I feel like it will flex and take the stress off of the copper pipe.
All good points, never even gave thought to using just heater hose.... :headwall: