Aqua hot off or on

[grimb]

2001 Monaco Just returned to motorhome in Florida for the winter. Turned both electric and diesel aqua hot switches on. No hot water. Turn off and on aqua hot breaker in side coach. Still not on. What do I look for next?

[FIX-IT-BOB]

Good day, The place to start is get the manual online

But the quick is might need a reset ( low voltage controller ). OR the sensor for the temp may have the controller thinking the water / heater is already at full temp. THUS keeping all from starting

Cheers

[vito.a]

The older Aqua Hot units do not have the LED panel which makes troubleshooting more creative.
First, the electric element will take SEVERAL hours to heat up all the boiler fluid which in turn heats up the water as it flows through the coils.

Do you hear the diesel fired burner startup? It first turns on the fuel pump, then ignites, and then continues to run for about 20 min. Listen carefully and you can hear the distinct stages as it starts up.

Usually if it's not igniting the pump will start and run a few seconds and the flame sensor does not see a flame and it shuts down. This can be caused by either lack of fuel or a bad ignitor.

So, leave the electric on but shut the diesel burner off, wait a few minutes then turn it back on and listen carefully to it. If it is still bad download the troubleshooting page and start through the matrix. Or take it to a service center.
Good luck!

[RobRoy]

Great Inf so far.

A wild guess to add to the pot and something that comes to mind is possibly low coolant level ...or failed sensor.... as some of these units use a low coolant level sensor and some dont IIRC.


As already stated earlier and IMO also you need to know the exact model AquaHot unit that you have as there are minor differences and updates in these units.

As Vito said in his detailed response turn the electric portion of your AQ on and the diesel off and give it an hour or so and see if you have hot water? Doing so will give you a starting point and get you headed in the right direction.


I can tell you that on my AquaHot unit years back I was chasing a crazy intermittent diesel ignition issue for over a year.

I even paid out big time for one of the name brand clown show so-called RV specialist to miss-diagno$is it for me and say it was fixed.

I ended up finding the issue on my own and that the relays on the circuit board under the Aqua Hot Cover were very very loose and one was even missing a retaining clip about to fall out and that fixing that problem with all the relays retained properly fixed my issue at that time.

With a service manual a DVOM the knowledgeable crew here at iRV2 these folks will get you up and running.

Happy Trails

[153stars]

If there's a low fluid sensor I would check actual boiler level under the cap ,not the expansion tank. AH are hard on the caps if recovery valve is bad, it will not exchange fluid back and forth eventually going low. Take care to push cap down and not abuse the neck these have been known not to be soldered down/in the greatest. I don't like lever caps but it helps to make easier to remove. Check the condition of the hose right out of neck to tank these have been known to crack.At Running on top of boiler sees more heat that off a radiator. I replace mine with reinforced fuel / coolant hose except into tank that had plastic hose barb. I added a hose barb splice to old non reinforced hose.

[RobRoy]

Originally Posted by 153stars

If there's a low fluid sensor I would check actual boiler level under the cap ,not the expansion tank. AH are hard on the caps if recovery valve is bad, it will not exchange fluid back and forth eventually going low. Take care to push cap down and not abuse the neck these have been known not to be soldered down/in the greatest. I don't like lever caps but it helps to make easier to remove. Check the condition of the hose right out of neck to tank these have been known to crack I replace mine with reinforced fuel / coolant hose except into tank that had plastic hose barb. I added a hose barb splice to old non reinforced hose.

Thank you!. I didn't go in to detail and probably should have.

If the OP decides to to check the Boiler fluid do so at the AH tank itself as described above and read the above post twice it's pretty sage advice

IIRC when I checked my boiler fluid at the cap the first time, due to the very limited room above the AH boiler tank IIRC I grabbed the cap with a large pair of channel locs and very gently wiggled it then I pry'ed down and gently rotated the cap CC to release it.

keep in mind once you release the cap and rotate it @ 1/4 turn the cap will pop up be loose but will need to be pressed down again to finish rotating it to release it.

As described above, where the radiator cap is soldered to the boiler tank it is very suspect at best.

Happy Trails