American Coach: Aqua Hot won't heat the water

[Dezignr Gal]

Hi
We are newbies as RV owners of an 2022 American Dream 45A. Our coach uses the firefly Polaris system.

We are now without hot water in a cold climate in Tennessee. Our Aqua Hot system is 450D.

We were without heat as well as hot water last night, but found a way around the settings on the firefly system to engage the heat, although, it is not coming out from the bottom vents as it was previously along the floor boards, but now from the ceiling registers. Not sure why the change and what happened?

We are trying to trouble shoot why the Aqua Hot won't heat our water tanks but will still produce heat?

Anyone with trouble or experience in this issue and can offer suggestions are greatly appreciated. We have tried uTube and google searches thus far with little assistance.

Thank you,

[n2zon]

Welcome to iRV2! With any luck someone who has the same coach will be along some time soon.

I am not at all familiar with the controls on your coach. However, it sounds like you have the heat set to heat pump (the dual AC/heat pump units on the roof) rather than furnace (the AquaHot). "Somewhere" should be a setting to turn the AH on (which will provide hot water) using the electric element or the diesel burner or both. "Somewhere (else)" should be one that uses it for heat instead of the heat pumps.

You will want to solve this quickly, since the heat pumps do not work well below about 45*F.

[alank]

I really feel for you getting into a coach like that and not being familiar with the controls. Most things are controlled in the FireFly screens.

Your Aqua Hot has its own set of controls to turn it on to electric and/or diesel heat. Each must be turned ON separately in the firefly to heat the boiler fluid, then you'll have hot water and heat coming out the floor vents around the coach.

The ceiling heat is from A/C heat pumps and is completely separate from the AquaHot for producing heat, and turned ON separately in the firefly. Both the heat pumps and AquaHot are controlled by the firefly thermostat settings, depending on what you have turned on.

You also have floor heat (the greatest thig) and must be turned ON to the desired heat separately in the firefly.

There is most likely a fireplace which will produce heat and probably has buttons on the fireplace and a remote for its controls.

Hope all this confusion gets you started, Good Luck

[Dezignr Gal]

John~
Thanks for your speedy response! We have been experimenting with setting trying to recreate what did work for us previously. We currently have the AH on both burner and electric and have just had just it on burner still resulting in hot water. I realize that being on electric (heat pump) is insufficient for the colder climes we are experiencing.

I just can't understand why we have heat but no hot water...? IDK if this is a thermostat issue or a setting or ??? Everything seems to be "on" and there are green lights on the Polaris not indicating an issue.

Thank you for weighing in!
Have a lovely evening,
Margaret

[Dezignr Gal]

Alank~

All had been working perfectly up until last evening. Something has changed or broke and is no longer working. We're trying to understand what and why it changed. We have been using the floor heat and had wonderfully hot water until dinner time last night when things went cold.
Thank you,

[alank]

Go out to the Aqua Hot bay and look at the controller, yours is different than mine, different year, but see if the lights indicate a low voltage indication that cuts the Aqua Hot off and the controller needs to be reset. I use a little non metalic stick (sandwich spear is perfect) that I push through a hole to trip a "reset" switch. First thing to look at if the AquaHot doesn't come on.

Also, have you used this coach some or is it your first time out? Being camped, if the big red switch next to the charger/inverter isn't turned ON, the shore power won't charge your batteries and will result in a low voltage.

[chuckftboy]

You should have a control panel on the AH. Have you checked to see if it has tripped out. There is a reset button on the panel and you need something like a toothpick to reset it

[Archer2]

As far as I know if you have heat from the AquaHot (forced air registers at floor level spaced around the perimeter and/or radiant floor heat) then the water heater portion of the AH is also working.
I’m wondering if you are experiencing water that is not nearly as hot as you are used to due to very low temperature city water supply. The AH is only capable of raising the input water temp by about 50° F and even then it can only supply 1.5 gallons of hot water per minute. So a combination of very cold city water coupled with relatively high water pressure can result in less than piping hot water.
Something that Entegra suggests is to turn on the Fresh water tank heater, wait until it is registering some warmer temp (like 65° or whatever) then begin to draw (heated) water from the tank instead of city water. It will still go through the AquaHot and get heated. The point is to get the input water temp up so that when the AH adds 50° to it it will be more comfortable.

Note that, assuming that you are correct and that you have hydronic heat and that that seems to be working just fine, there’s no point in wasting your time looking for AH controller faults. The AH hydronic heating system uses electric elements plus a 50kBTU burner to heat a tank of boiler fluid. The hot boiler fluid is pumped through tubing under the floor and through heat exchangers. The hot water supply is just a copper coil that is immersed in the boiler fluid tank. So if the hydronic heat is working then the water heater pretty much is guaranteed to be working as well.

Lastly, the AquaHot systems since at least 2021 don’t use the separate control panels with the low voltage reset. They use a device they call the “Reporter” that interfaces with the Firefly RV-C controller network and the Reporter doesn’t have the lights and reset switch.

[Archer2]

Hey Dezignr Gal, did you have any luck figuring out why your water wasn’t heating?

[Dezignr Gal]

Good morning~

Thank you all for your suggestions in how to trouble shoot the AH 450 D.
Yes, it was a simple matter of pushing reset on the led panel on the AH. Thank you for that key piece of advice! Now we know it won't trigger all kinds of other "issues" we don't know about...LOL!

Thus far, everything is working as expected and we have HOT running water from all faucets and warm air flowing from the floor board vents. Mission accomplished--YAY!

We decided, after speaking to one of the Technician's from the LazyDays Dealership in Seffner, FL, to take the RV to a Lazydays Dealer in Knoxville thinking that a faulty sensor might be a culprit.

We elected to stay overnight on their lot to see if all stayed in working operation and thus far, we are golden. I wish we knew what had triggered the "overheat" sensor to kick off the AH. It would be senseless to start buying all kinds of replacement parts not knowing what would work in the "event of this or that". But I would certainly entertain a part or two if this is a continual issue. I just don't know. Anyone else with this problem recurring?

Thank you all again for your expedient responses and assistance. Have a blessed day!

[n2zon]

Originally Posted by Dezignr Gal

Good morning~

Thank you all for your suggestions in how to trouble shoot the AH 450 D.
Yes, it was a simple matter of pushing reset on the led panel on the AH. Thank you for that key piece of advice! Now we know it won't trigger all kinds of other "issues" we don't know about...LOL!

Thus far, everything is working as expected and we have HOT running water from all faucets and warm air flowing from the floor board vents. Mission accomplished--YAY!

We decided, after speaking to one of the Technician's from the LazyDays Dealership in Seffner, FL, to take the RV to a Lazydays Dealer in Knoxville thinking that a faulty sensor might be a culprit.

We elected to stay overnight on their lot to see if all stayed in working operation and thus far, we are golden. I wish we knew what had triggered the "overheat" sensor to kick off the AH. It would be senseless to start buying all kinds of replacement parts not knowing what would work in the "event of this or that". But I would certainly entertain a part or two if this is a continual issue. I just don't know. Anyone else with this problem recurring?

Thank you all again for your expedient responses and assistance. Have a blessed day!

Things have changed quite a bit since ours was made, but I would expect:

- The problem to come back; AHs can have intermittent problems that become more frequent until they just stop working. Going to get it looked at sounds like a good plan.

- The AH to set some sort of fault you can display, somehow, which will provide important clues about what needs to be done. That information will be very important to whoever looks at it.

[Cat320]

Unless things have changed, the 450D will provide hot water and coach heat....BUT not at the same time. Hot water takes precedence. If the furnace is running, and the hot water gets turned on...the hot water comes on and furnace shuts off. When the water is turned off, coach heat will start again.

[Archer2]

Glad you got it going. I went back and re-read the thread and I think I misunderstood something. In post #4 you said …“can't understand why we have heat but no hot water...?”.
I now see that you meant that you had heat from the 3 roof-mounted AC/Heat Pumps coming from the ceiling vents. But I thought you were saying that you had heat coming from the floor registers, which are heated using the AquaHot. That would not make sense.
Also when you say you pushed reset on the LED panel, are you referring to a virtual button on the rectangular box with a touchscreen LCD display (the Reporter unit) as opposed to a separate black panel with red and green LEDs and a physical “Reset” button (old-style physical control board) that had to be pushed using a toothpick or similar tool?

[alank]

Originally Posted by Cat320

Unless things have changed, the 450D will provide hot water and coach heat....BUT not at the same time. Hot water takes precedence. If the furnace is running, and the hot water gets turned on...the hot water comes on and furnace shuts off. When the water is turned off, coach heat will start again.

I would like to make a bit of clarification as I understand the Aqua Hot operation.

Hot domestic water, as for a shower, takes priority over heating the air within the coach. The furnace (AquaHot) does not shut off during use of hot water, it continues to operate on elec. and/or diesel as needed. What shuts off are the circulating pumps that is supplying boiler fluid to all the heaters located around the coach, while you're taking a shower, then when the shower (hot water) is shut off, the AquaHot circulating pumps come back on to continue heating the air within the coach.

It is possible that the circulating pumps and heaters can take so much heat out of the boiler fluid that you won't have as hot of water as desired for a shower.

Also, just for information, if the OP parked the coach with 1/4 tank of fuel, the AquaHot may have started out working, then reached a point where it couldn't pick up fuel any more because of the 1/4 tank reserve for the engine.