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Topic: Aqua hot help (Read 1255 times) previous topic - next topic

Aqua hot help

No hot water from my aqua hot. Inside breakers are not tripped. Anything else to check. I have both electric and diesel on.
Gerard Caswell
Eunice, LA
2006 Phenix
2011 GMC Sierra P/U 4x4

Re: Aqua hot help

Reply #1 –
Quote from: lavocat –
No hot water from my aqua hot. Inside breakers are not tripped. Anything else to check. I have both electric and diesel on.

This will get you started until Roger Berke checks in.

When you turn on the diesel heat, the diesel burner goes into a lighting sequence.  The following things happen in this order.

The blower motor starts, which starts the fuel pump.

The motor runs for about 1 minute to allow fuel pressure to build up and stabilize.

The fuel solenoid opens (spraying fuel into the burning chamber), the ignition coil starts creating a spark across the electrodes (igniting the fuel that has been sprayed into the burning chamber).

There is a very slight delay.  The photocell (that is adjacent to the burning chamber) looks for light from the burning diesel fuel.

If the photocell sees light, everything is good and the burner will continue to run.

If the photocell DOES NOT see light, the fuel solenoid closes and the `diesel' light next to the switch in your coach goes out. The blower continues to run (purge cycle) for about 2-3 minutes to purge unburned diesel (and heat if the unit has been running).

Blower motor shuts down.

As you can see, this is a complicated sequence. If ANY component fails to operate properly, the diesel burner will not operate.

There is some troubleshooting information in the Aqua-Hot Service Manuals  Library - Aqua-Hot for your unit. 

Some things that you can check:

Fuel – The fuel tank pick up line is like the generator, it will not pick up fuel if the tank is less than ¼ full. I have heard of coaches that won't draw diesel if the tank is less than 1/3 – ½ full. You would know your coach better than anyone else if this is the issue.

It could be any of the following items that have failed. Fuel pump, solenoid valve, clogged nozzle, ignition coil (+wires + electrodes), or photocell.  On the older (non electronic control board) Aqua-Hot, the high limit thermostat.

You will be able to get at least some heat from the electric element.  The electric and diesel systems are completely separate.
The selected media item is not currently available.Barry BEAM #16014
2003 U320 40' AGDS
Beamalarm, Foretravel technical help and specifications
"Whatever the mind can conceive and believe, it can achieve"

Re: Aqua hot help

Reply #2 –
The low tank cut off light is lit up. Dont know what that means. Got plenty water and diesel. If anyone can help email me
Caswelllaw@aol.com
Gerard Caswell
Eunice, LA
2006 Phenix
2011 GMC Sierra P/U 4x4

Re: Aqua hot help

Reply #3 –
Quote from: lavocat –
The low tank cut off light is lit up. Dont know what that means. Got plenty water and diesel.

A quick Google search says it means low boiler coolant level.  If the level is physically fine, then probably a bad float switch.

Michelle
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: Aqua hot help

Reply #4 –
Those float switches go bad all the time. I have replaced quite a few. You can ohm out the switch to see if it has continuity. You can also get on the aqua hot forum that Roger Berke has to get further information Forum Rv Hydronic Heater Repair - Welcome and he also has parts, He will want to know the model # of your unit
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: Aqua hot help

Reply #5 –
     If you are near Houston, TX call Rudy Legett He is very good on diagnosing and repairing the Aqua-Hot
Laurel Hill, FL
 To do is to be---- Nietzsche
  To be is to do-----Kant
  Do be do be do----Sinatra

Re: Aqua hot help

Reply #6 –
Gerald,

Did you solve the problem?

I sent you an e-mail at 9 pm sharing how to call me.  I can probably get you going or at least find the problem if you call soon.
Rudy Legett
2003 U320 4010 ISM 450 hp
2001 U320 4220 ISM 450 hp
1995 U320 M11 400 hp
1990 Granvilla 300 hp 3208T
Aqua Hot Service Houston and Southeast Texas

Re: Aqua hot help

Reply #7 –
Update on the aqua hot problem.  Rudy was able to diagnose that it was the float switch and since I was in Houston he came over and changed it and did my annual service while he was there.  If you need aqua hot service, give Rudy a call, he will do you right.
Gerard Caswell
Eunice, LA
2006 Phenix
2011 GMC Sierra P/U 4x4