Odd Aqua-Hot behavior

[Pwdr Extreme]

The Aqua-hot in my new coach does not seem to be working as well as it should compared to my previous Entegra’s. Domestic hot water in the shower will start off quite hot, then after a minute or two gradually cool off to not much more than luke warm. If I wait for the Aqua-hot burner to shut off a few minutes later and run hot water again in the sinks, the outcome will be the same. Quite hot (what I remember as being available continuously in my previous Cornerstone) and then slowly cool off to luke warm.

This is with the motorhome parked inside a shop heated to 53 degrees using the diesel setting on the boiler.

I’ve also felt the front of the coach doesn’t stay warm near as well as my last Cornerstone which I initially attributed to floor plan differences, now I’m wondering if it’s related.

Entegra referred me to a mobile Aqua-Hot repairman in my area (Montana) who is unfortunately in Quartzite till May. I called Aqua-Hot and she just referred me to the service manual.

Has anybody experienced anything similar and might have some insight on what to look for?

[777 Driver]

If the diesel burner is cycling normally, as I understand the system, the only thing between the cold water input to the water heating coil inside the boiler tank and coach hot water system is the "Tempering Valve".

Here's a link to the AquaHot 450D service manual: https://drive.google.com/file/d/1DRL...ew?usp=sharing

Starting on page 27 is a process to troubleshoot the Tempering Valve.

Just an afterthought and, since I don't have one installed, is it possible that the shower miser is cycling hot water back into the fresh water tank. I'm really just guessing on that one.

Good luck...nobody likes a luke warm shower.


Take care,
Stu

MSU '73 BS Math

[Lv2Roam2]

Agree with Stu - on our 450D we had to cycle the tempering valve from full stop to full stop a couple of times when it was new - no problems since. Given you have a fairly new system also run it with all zones 'on' including the hot water and engine preheat and see if you have any bubbles show up in the reservoir tank - could be some air pockets.

[Pwdr Extreme]

First time I’ve had a shower miser, I kind of wondered if maybe it was allowing some cold water, but would that affect the bathroom and kitchen faucets as well? I picked up the coach in Florida right before Christmas then drove a few days home to Montana, so every heating zone definitely got a chance to run for several hours, I would think that would have worked out any air pockets? The cartridge in the shower was originally installed backwards, I turned it around and experience the cool down. I called Delta Faucet and they felt the cartridge might be bad as they have seen that before. New cartridge acts the same way, thats when I thought to try running the sinks for several minutes and realized it’s basically the whole domestic hot water loop that cools down after a few minutes. It’s been doing it since the day I picked it up. I showered a few times with the valve set to cold (to get hot water) and just dealt with the luke warm shower after a short time, all the while shrugging it off thinking it would take care of itself when I turned the cartridge around once I got home. Obviously it didn’t. I would say I’ve turned the shower miser valve from stop to stop probably a dozen times while testing the system…

[RVFunlovers]

I have not had that issue. I don’t think the shower miser would cause your issue. The valve diverts hot or cold water from the shower head to your fresh water tank.

If your heat is not working properly as well as hot water throughout the coach I would dig into the Aquahot.

I spent 6 days at NIRVC when I got the last coach and worked with them on all bugs before I left the lot. My Aquahot had issues from the start. It took me a night to realize that my front heat was not working properly.

Good Luck.

[Pwdr Extreme]

So after learning there is nobody in Montana that can work on an Aqua-Hot (one mobile repair tech is certified but he’s in Quartzite till May) I called Aqua-Hot only to be told where to download the service manual for my unit (the previous one linked was for an older model) and I started diagnosing it myself.

As I was running thru the flow chart I determined the “stir pump” to be inoperative. Once I pulled the covers off and started checking things with my meter, I learned that whoever assembled it screwed up. They didn’t have one of the insulated spade connectors hooked up correctly, they just shoved the female part into the housing of the male part without the two connectors actually making contact. I hooked it up correctly and viola! unlimited “hotter than you want it” water to shower with! I’m assuming (hoping) this will solve the poor heat performance in the front zone as well. Won’t know till I take it out again as it is currently sitting in my heated shop.

I can’t believe that Aqua-Hot didn’t at least check their OWN diagnostics after they assembled it, let alone do a test run.

[brobox]

Originally Posted by Pwdr Extreme

So after learning there is nobody in Montana that can work on an Aqua-Hot (one mobile repair tech is certified but he’s in Quartzite till May) I called Aqua-Hot only to be told where to download the service manual for my unit (the previous one linked was for an older model) and I started diagnosing it myself.

As I was running thru the flow chart I determined the “stir pump” to be inoperative. Once I pulled the covers off and started checking things with my meter, I learned that whoever assembled it screwed up. They didn’t have one of the insulated spade connectors hooked up correctly, they just shoved the female part into the housing of the male part without the two connectors actually making contact. I hooked it up correctly and viola! unlimited “hotter than you want it” water to shower with! I’m assuming (hoping) this will solve the poor heat performance in the front zone as well. Won’t know till I take it out again as it is currently sitting in my heated shop.

I can’t believe that Aqua-Hot didn’t at least check their OWN diagnostics after they assembled it, let alone do a test run.

If one pump was not connected correctly, the same guy may not have connected the boost pump for the front heat correctly. That pump is located on the passenger side, behind a screw on panel just about even with the back end of the kitchen, in the basement. You should be able to hear it running with the basement door open if is wired correctly.

[Pwdr Extreme]

Originally Posted by brobox

If one pump was not connected correctly, the same guy may not have connected the boost pump for the front heat correctly. That pump is located on the passenger side, behind a screw on panel just about even with the back end of the kitchen, in the basement. You should be able to hear it running with the basement door open if is wired correctly.

I will absolutely check that the next time I’m at my coach. I assume the Aqua-Hot was assembled at the factory and since the problem I found was with the internal stir pump within the Aqua-Hot itself, I’m guessing the problem was there from the beginning and Entegra didn’t catch it when the plumbed in the rest of the coach to the system. The pump you are talking about is probably installed by Entegra? Looking at the manual, I see there are two Boost pump outputs, do you know if the 2nd one is used and where? The new Aqua-Hot with the Reporter is actually pretty nice for diagnostics, I can go in and turn on the individual pumps separately and listen for them without having anything else running. I will definitely do that and check for the front Boost pump you are referring to.

[RVFunlovers]

Originally Posted by Pwdr Extreme

I will absolutely check that the next time I’m at my coach. I assume the Aqua-Hot was assembled at the factory and since the problem I found was with the internal stir pump within the Aqua-Hot itself, I’m guessing the problem was there from the beginning and Entegra didn’t catch it when the plumbed in the rest of the coach to the system. The pump you are talking about is probably installed by Entegra? Looking at the manual, I see there are two Boost pump outputs, do you know if the 2nd one is used and where? The new Aqua-Hot with the Reporter is actually pretty nice for diagnostics, I can go in and turn on the individual pumps separately and listen for them without having anything else running. I will definitely do that and check for the front Boost pump you are referring to.

Good find fixing the pump. Any part can fail but it is always most concerning when things are not built right from the start. In your case wired or connected where it can not work properly.

That means Entegra and your dealer did not check the functionality fully. What dealer did you use? The way Entegra uses the Aquahot system a lot needs to be tested. Electric and diesel, floor heat, front, kitchen, bedroom, and bath register, etc…. And tested enough to make sure it will cycle correctly, etc…

I know the NIRVC team in Nashville went through my Aquahot thoroughly. They found issues and corrected them. One of my pumps was bad. And of course my Aquahot has broke since then as well…. The entire system is one of the weak links in the coach. At least for northern RVers.

[brobox]

Hal, what you are saying is so correct. The Aqua Hot on my 14 was a nightmare with the two motor recalls and failures that went with them. Since then Aqua Hot has changed ownership to Airxcel. I couldn't agree more about a through delivery check when picking up a new coach. Much easier to catch it on the dealers lot that when needed at 20 degrees.