Aquahot “Burner failed to ignite “ fault

[Mr. Banker]

Greetings,

2019 Phaeton 40IH - New to us purchased 08/2021 - Full timers

Two weeks again I saw the fault on the interior Spyder main panel for the diesel flashing on the Aquahot. Turned off and back on to reset ran a couple days with no issues. Then it continued to fault after reset. Did my research and discovered that this coach had never had its Annual Service performed for the AH system.

Order the annual kit from AH directly and took the coach into an AH certified repair facility in the San Antonio area. Repaired and on our way. 3 days later, same fault.

Now in Albuquerque, NM locate yet another AH service center. Tech looks it over and says needs to replace the burner nozzle, I balked saying it was just new 5 days ago. He says it was possibly damaged on installation. Ok $15 part go ahead. Has the coach for an hour says he changed the nozzle, checked the fuel pressure aligned the igniters and cleaned the soot from the burner tube. Cycled it 6 times with no faults observed.

Works perfectly for 3 days then same fault. Call the same company back and he calls AH and they say it is a burner controller module that “might” be the issue. Something else I wonder about is the runtime for the purge after each cycle ends. From burner cutoff the purge fan runs for about 3 mins. That seems excessive.

So it would seem to me that technology should exist on this system when trouble shooting, that a truly “qualified “ and factory trained technician, should have explicit tools to diagnose that the controller is truly bad and not to just place this $990 part in the AH system to see if that solves the problem. As is customary no returns on electronics once installed.

As this is my first ever post to the forum I hope it is detailed enough yet not a run on train wreck of details.

Thanks in advance for your suggestions as to repair. Headed to Phoenix area and then to Yuma for a month.

[Ranger Smith]

I had an intermittent problem similar to yours with my Aquahot. No one could figure it out. I got the wiring diagram out and traced it to the High temp cutoff intermittently going from continuity to about 5k ohms and shutting down the system.

[plweljr]

You could check Roger Burke's forum. As he will tell you, there are many,many possible causes for the burner to fault. My experiences with the black plastic controllers are, they are a POS. Way over priced and you may have to go through 3 before you find one that works. Good luck

[chuckftboy]

You mentioned that the 2nd technician cleaned up the soot. Did he check the air adjustment? Shouldn't have any clean up needed in 3 days of operation. If the flame sensor gets covered with soot form a bad air adjustment, the burner will shut down because it doesn't see the flame. Just a thought.

[Mr. Banker]

I will contact #2 back tomorrow and ask him. Thanks

[jlturner]

Originally Posted by Mr. Banker

I will contact #2 back tomorrow and ask him. Thanks

Aqua Hot factory tech - Jim Yates

(800) 685-4298

[Martinichuck]

We had a similar problem with our AH. It would go to fault once or twice a week. Turning off and back to on would usually correct the problem and we would be good for several more days. This lasted for 6 to 8 months.

We then encountered an issue where the purge fan(not sure that’s what it’s called) would start, like it’s supposed to do, but the diesel burner would not light but the fan also would never stop unless I went out and disconnected the burner module.

After discussion with Red Bay they recommend the replacement of the module. I ordered, and it hurt at $800+, but I received what is the latest and greatest module. Smaller and mounts different. I think this module has had 2 or 3 revisions in the last few years.

Once installed all has worked.

My biggest issue is the the AH operates slightly different now as noted on the Spyder panel. I cannot get anyone in Spyder, AH or Red Bay to confirm these new observations are “normal “.

My observation are:
When setting to diesel, Spyder panel goes to fault for 2-3 seconds then shifts to on. Old module never did this. Just went to on. Works as one would expect after this observation.

Old start up almost always initiated a purge by the diesel burner whether it needed to heat or not. New module process may not do this if no heat is needed.

I do notice a reduction of cycling by the AH throughout the day. Old module cycled, what appeared to us anyway, constantly. Several times in an hour. New module seems to not call for this to happen quite as often.

I have asked AH if these new indicators are OK. They seem to not want to respond to my inquiries.

Red Bay only offered that I reboot Spyder. This didn’t resolve anything.

FYI this is our 4th burner module on this AH.

First quit at 3 months old. Second quit 24 hours after Red Bay installed. 3rd quit, as described above after 3 years.

Not a fan of the AH system or their lack of customer support. Never had issues with propane heating in 30 plus years of RV ownership.

[Skokkian]

I've followed trouble shooting guide and all points to the controller. I've opened the controller and see nothing wrong. Is there any where I can send the controller for testing?

My problem is not diesel, not the fuel solenoid and not the VDC high temp thing. It appears the fuel solenoid is not getting the message to open to allow diesel to the nozzle to be ignited.

Wouldn't it be nice if the AH unit was on a slide!!

[jlturner]

Originally Posted by Martinichuck

We had a similar problem with our AH. It would go to fault once or twice a week. Turning off and back to on would usually correct the problem and we would be good for several more days. This lasted for 6 to 8 months.

We then encountered an issue where the purge fan(not sure that’s what it’s called) would start, like it’s supposed to do, but the diesel burner would not light but the fan also would never stop unless I went out and disconnected the burner module.

After discussion with Red Bay they recommend the replacement of the module. I ordered, and it hurt at $800+, but I received what is the latest and greatest module. Smaller and mounts different. I think this module has had 2 or 3 revisions in the last few years.

Once installed all has worked.

My biggest issue is the the AH operates slightly different now as noted on the Spyder panel. I cannot get anyone in Spyder, AH or Red Bay to confirm these new observations are “normal “.

My observation are:
When setting to diesel, Spyder panel goes to fault for 2-3 seconds then shifts to on. Old module never did this. Just went to on. Works as one would expect after this observation.

Old start up almost always initiated a purge by the diesel burner whether it needed to heat or not. New module process may not do this if no heat is needed.

I do notice a reduction of cycling by the AH throughout the day. Old module cycled, what appeared to us anyway, constantly. Several times in an hour. New module seems to not call for this to happen quite as often.

I have asked AH if these new indicators are OK. They seem to not want to respond to my inquiries.

Red Bay only offered that I reboot Spyder. This didn’t resolve anything.

FYI this is our 4th burner module on this AH.

First quit at 3 months old. Second quit 24 hours after Red Bay installed. 3rd quit, as described above after 3 years.

Not a fan of the AH system or their lack of customer support. Never had issues with propane heating in 30 plus years of RV ownership.

Our Spyder panel AH diesel button blinks fault for a couple of seconds and then starts with no issues. That’s the way it’s always been? I assumed that was normal? We have a 2019 Bus.