Aqua hot 100-4s

[Donflem]

My shower overflowed the other day in my 2007 Dynasty and now I have no heat midship forward from the aqua hot. I had to cut the wire on the front blower to get it to shut off it would not shut off 🤷‍♂️. I would appreciate any feedback.

[vito.a]

First try the simple fix.  Remove all power from the coach and shut off the batteries and inverter.  You should have an Aqua Hot  system reset on the light display board,.  Do a reset (make sure you cycle the power off/on first).  

Then with power back on, cycle the main diesel burner switch off/on a couple of time.  

You should have been able to turn the thermostats off (black slider switch under the thermostat) and turn off the front blower fan.  

[Donflem]

Thanks Vito I will try that this morning. 

Don

[Donflem]

I tried the power off and on fix but no luck. I still have no heat from zone 1 any more ideas? Thanks

Don

[Chargerman]

I would check to see if the circulator pump for the problem zone is running when heat is called for. 

[k7jv]

Wow!  Several questions:

Gray tank must have overfilled?

Any idea how much water?

Where did the water go (drain from the floor), or did it just stay there?

Open your rear bay door (the AquaHot) and see if there's evidence of your water?

When you turn off the AH fan switch-pad button in the bath, does the fan turn off or just keep running?

No heat mid-ship forward, does that mean the living room/kitchen does NOT put out heat?

Do those fans turn on and off like they should, just no heat?

Answer these, then I'll see what I can share.

Wow!!!

[Guest Ray Davis]

Is your AH right below the shower?   First assumption is that water got into the electronics ( control box or board.)  If you feel you are able to crawl into the bay where you  can gain access you can remove the access cover and try blowing the water out if it appears that's it's present.  A hair dryer or compressed air will work.                      Mine has 3 relays that have clear plastic covers, those covers are held on by a wire clip easily removed to dry those out.   There is also a number of fuses inside the unit. 

Good luck, keep us posted

[k7jv]

Don, controlling the zones involves two control systems.  It requires operating the pumps to circulate the fluid and it requires operating the fan(s) to circulate the air. The control for both of these systems comes from the circuit board mounted behind the black panel in your aft basement compartment.  I don't know how electrically conductive gray tank water might be, but I would expect it to have more contaminants in it to allow conduction than would fresh water.

The terminal strips down both sides of the control circuit board provide the connections to the fans at each of the heat exchangers, and it provides the connections to each of the four circulating pumps that are inside of the AH enclosure.

For any of the fans to run, they have to get their power from that circuit board.  For heat to be delivered, that zone pump has to be getting its power from that circuit board, as well.  So I am thinking that is the only place in the whole picture that would be at the root of your problem.  If your shower is located directly above the AH, there is a good chance that a path could exist to let water get onto that control board.  Also, the control board is about the only part of the system that is not protected by the housing around the AH.

If it were me, I would take the front plate off of that control panel and inspect it for any contamination.  That black panel that it is mounted on is likely held in place by Velcro.  You can easily pull it forward and take it out of the compartment to get to the back of the circuit board.  My goal would be to clean up the board on both sides, the best I could.  I suspect that might restore normal operation to your system.

[Donflem]

Great idea thanks Jim I will try that today.

Don

[k7jv]

I don't know if I can describe this very well, but I'll share what I did with the control panel on our AquaHot in our '06 Dynasty.  I removed all four corner screws allowing the control panel to come off, and it also separated the control chassis from the back of the compartment barrier.  I then re-secured the two machine screws on the right side of the control chassis thus securing the right side of the chassis back onto the barrier, but with the control panel still off.  Then, I used the remaining machine screw hardware to secure the right two holes on the control panel to the barrier and to the two left side holes on the chassis.  This left the chassis securely attached to the barrier, like it was, but with the panel shifted its own width to the left.  I then secured the left side of the panel to the barrier with new hardware.

I did this because it is FAR easier to see which LED' are lit at any time, even in bright daylight.  It also allows easy access to the terminal strips with a voltmeter for any testing.  And it makes it easy to access the reset button, if you ever need to do that.  (I'm not sure that I have ever had to do that in 15 years of ownership, though.)  It is also very easy to refer to the markings on the panel and relate it to what you are seeing on the control board.

I am partially color-blind, and it is extremely difficult for me to see when an LED is lit and it is on the other side of a lens.  So this change made my life FAR easier!!

[k7jv]

Back in the days of Radio Shack, it was easy to get electronics spray cleaners.  Such may still be available at places like Lowes or Home Depot, but I haven't looked for it.  If you have some, or can find some, that would be one way to perhaps remove a lot of the contamination you may have gotten, if drying it out good doesn't correct your problem.  If it were me, I would try dry-scrubbing it with a relatively soft bristled brush to remove any surface contamination, before I tried any water or chemicals.  Whatever you do, don't use any chemicals that might significantly compromise the thin protective coating that may be on both sides of the board.  Actually, if contamination is the issue, any protective coating may not have been there in the first place, or it is already compromised.

If you do "attack" it with anything other than a brush or compressed air, you can power down the AH by pulling the top (on our coach) fuse on board #R5 in the rear run box.  There is a second fuse for the AH in the front run box on board #11, fuse #2, rated at 15 amp, but that fuse may or may not be used.  I've not tested it on our coach.

There are six AH fuses in the Intellitec cabinet, but I don't think you would need to be concerned about them.  Four of those (Kitchen HI, MED and LO, and the bathroom exchanger or exchangers) use control power from the AH control panel to operate a relay that then uses the power from the Intellitec equipment to actually power the blowers.  There are also two fuses in the Intellitec cabinet to power relays to enable either the electric heating element(s), or the diesel burner system, or both.  All six of those fuses feed loads that are just controlled FROM the AH control board, so they should not back-feed power to the control board in any way.