Community Forums

Wildbuckaroo · 09-30-2021, 06:40 AM

I have a 2005 Monaco Dynasty 42 ft and the Aqua hot seems to be making coolant as the recovery resavoir keeps overflowing all the time, so I thought maybe it was a bad rad cap. I replaced it and found the recovery tank was still overflowing out the top but we left on our trip anyways 🤷🏻*♂️ Now the first night of our trip I heard the water pump cut in three times in an hour, so I got up and shut it off. So now this morning I’m thinking water must be getting into the coolant and causing it to over flow. I’m pretty sure that this isn’t going to be good news but has anyone ran into this sort of a problem before?

zmotorsports · 09-30-2021, 07:30 AM

I hate to say this but you have a domestic water line cracked or split in the boiler. The older units, made prior to 2002, had the domestic loop wrapped around the exterior of the boiler tank by way of a heat conducting paste that transferred the heat from the boiler tank glycol to the domestic water line.

The one manufactured after that had the domestic loop routed inside of the boiler tank and were in direct contact with the glycol. One way to determine if the domestic water line or loop is compromised is if the surge tank overflows as the domestic water is under pressure and being introduced into the boiler tank.

Sorry, probably not what you wanted to hear. The most common cause of this issue is improperly winterizing a coach with Aqua-Hot and the domestic line freezing and splitting but I have heard also of a couple that had poor solder joints that started to leak at the boiler tank allowing domestic water to be introduced into the boiler tank.

96 Wideglide · 09-30-2021, 04:33 PM

Quote:

Originally Posted by Wildbuckaroo

Now the first night of our trip I heard the water pump cut in three times in an hour, so I got up and shut it off. So now this morning I’m thinking water must be getting into the coolant and causing it to over flow. I’m pretty sure that this isn’t going to be good news but has anyone ran into this sort of a problem before?

I'm sure several others have. Fortunately I'm not one of them!

I think your options are ship yours to one of a few guys that rebuild them, or, replace with a new unit

!

Wildbuckaroo · 09-30-2021, 05:03 PM

Well well, that’s pretty much what I was thinking as it only leaks with water pressure but I still as hoping for a different answer. Now I’m a licensed auto tech, I do all my own plumbing and electrical work or whatever needs to be fixed. I have no fear of removing the Aqua hot and rebuilding it myself. It sounds like you know a lot about these and would you know if I need to order any special parts or would I just need bulk copper flexible tubing if a pipe is cracked? If was a solder connection would I be able to access it without removing the unit or should I just pull it out. I have owned this unit for 7 years and I always winterize it myself by sucking in 7 gallons of antifreeze at the water pump and run everything until it’s flowing pink out hot and cold faucets. We have been using the RV all summer with no issues until recently, so you wouldn’t think it was from poor wintering would you? Looking forward to your reply 96 Wideglide.

96 Wideglide · 09-30-2021, 05:20 PM

Sorry, servicing them is all I know.

Can't imagine it won't have to come out of the coach, whether you repair it, or send it out.
I believe the only owner repair I've read on these boards was an older model like Mike mentioned, that had the copper fresh water coil on the outside of the boiler tank.

Poohbear7278 · 09-30-2021, 06:27 PM

Quote:

Originally Posted by Wildbuckaroo

Well well, that’s pretty much what I was thinking as it only leaks with water pressure but I still as hoping for a different answer. Now I’m a licensed auto tech, I do all my own plumbing and electrical work or whatever needs to be fixed. I have no fear of removing the Aqua hot and rebuilding it myself. It sounds like you know a lot about these and would you know if I need to order any special parts or would I just need bulk copper flexible tubing if a pipe is cracked? If was a solder connection would I be able to access it without removing the unit or should I just pull it out. I have owned this unit for 7 years and I always winterize it myself by sucking in 7 gallons of antifreeze at the water pump and run everything until it’s flowing pink out hot and cold faucets. We have been using the RV all summer with no issues until recently, so you wouldn’t think it was from poor wintering would you? Looking forward to your reply 96 Wideglide.

If you know how to fix things , jerk that puppy out and dig in. That’s how you learn and at this point what do you have to loose. When you get the price on these units that will help make up your mind. I have one that is leaking around the filler neck but when it gets below that it stops and continues to heat so I go on. But one day I will pull it and fix. Good luck with your endeavor keep us posted

RamiDav · 09-30-2021, 07:27 PM

There is an option for the filler neck repair, it's not cheap, $240 but it may be good for some owners.

https://www.parts.rvhydronicheaterre...?categoryId=-1

Ray 03 Windsor

96 Wideglide · 09-30-2021, 07:32 PM

The neck repair will be a walk in the park compared to getting into the tank to repair a leak in the fresh water coil.

zmotorsports · 10-01-2021, 06:51 AM

Rebuilding one of the older units with the domestic coil on the exterior of the boiler tank is a viable option as several forum members have done that and documented it well.

As for the newer units with the domestic loop on the interior of the boiler tank, I have not done one of those nor seen it done. That does not mean it cannot be done if you feel competent around tools and mechanical processes. There was a guy here who pulled his out of his coach and discovered it was an external leak before he needed to go into the boiler tank but while he had it out he sand blasted, painted and completely refurbished his unit before reinstalling it and he did an amazing job. Sorry I cannot remember who that was but try the search box to see his process.

As for actually getting into the boiler tank on the 2003+ design, I would assume that one end of the tank had to be welded on after the copper domestic coil was installed inside of the tank so I see no reason why it couldn't be cut off, repair or replace the copper tubing and then re-weld the end of the boiler tank back on. I have welded quite a few tanks on various projects over the years so I feel if it's been welded before it should be able to be welded again.

I think I would pull the unit from the coach and get it on the bench then perform a few more pressure tests to confirm and then cut the end off where the tubing comes out to gain access to the inside of the tank as well as have access to the bulkhead where they transition through the tank. Once repaired and welded back together I would suggest additional pressure testing to confirm before putting it back in the coach.

moisheh · 10-01-2021, 07:37 AM

Some of the rebuilt units from one expert are made of used parts. If you join the wanderlodge owners forum there are some long threads on repairing aqua hots with cracked lines. I think there are pictures. It is well written.

RamiDav · 10-01-2021, 10:43 AM

We have some guys on here that can build or repair anything and Mike of Zmotorsports has got to be at the top of that list.

On the other Monaco forum, there was a Dr. quite a while back that explained how he built his own hydronic system using mostly German components. Our Aqua-hot burners ( Webasto ) are German .
The name Eberspaecher comes to mind but there are others too, Truma is another.

https://www.eberspaecher-na.com/prod...pplications/rv

I imagine those posts were lost when Yahoo shut down their groups.
Anyway, the boiler tank is essentially a heat exchanger and reservoir that Aqua-hot manufactures but AFAIK does not sell.
Surely other exchangers exist that could be substituted if someone could just track one down.
Actually, one could be built/copied in the garage/shop, but that would be quite an undertaking so finding a replacement is a more viable
alternative for most of us.

Ray 03 Windsor

zmotorsports · 10-01-2021, 12:37 PM

Quote:

Originally Posted by RamiDav

We have some guys on here that can build or repair anything and Mike of Zmotorsports has got to be at the top of that list.

On the other Monaco forum, there was a Dr. quite a while back that explained how he built his own hydronic system using mostly German components. Our Aqua-hot burners ( Webasto ) are German .
The name Eberspaecher comes to mind but there are others too, Truma is another.

https://www.eberspaecher-na.com/prod...pplications/rv

I imagine those posts were lost when Yahoo shut down their groups.
Anyway, the boiler tank is essentially a heat exchanger and reservoir that Aqua-hot manufactures but AFAIK does not sell.
Surely other exchangers exist that could be substituted if someone could just track one down.
Actually, one could be built/copied in the garage/shop, but that would be quite an undertaking so finding a replacement is a more viable
alternative for most of us.

Ray 03 Windsor

I appreciate that but I am in awe of many of our fellow forum member's projects and abilities.

Burgy · 10-01-2021, 01:13 PM

https://www.monacoers.org/topic/668-aqua-hot-rebuild/

RS505 · 10-01-2021, 02:03 PM

We bought our 03 Dynasty in December, and two days later (after moving into it from our old Itasca) spent two months straight living in it. In Golden CO. The Aqua Hot was dead, and that was a major problem lol.

I fixed the long list of various things wrong with it myself after work every day. Took me about three weeks. I haven’t had a single issue with it since.

There’s a Aqua hot guy named John Carillo who was relatively close to me when I was doing all of this work. I bought my parts from him and he gave me pointers throughout this process. I got several tours of his shop, and checked out his operation.

If my tank failed, I’d have him rebuild the entire unit. I’m a welder and machinist and could do it myself, but it’s not worth it to me. The tanks he build have numerous small improvements and mods, and he’s set up to do this day in, day out.

He’s busy, but worth the effort to get in touch with him is worth it