[Latitude 28]

Hello All,
Several weeks ago it turn cold and I fired up the Aqua Hot to give the coach some heat.  It heated up to temp with no issues....checked on it latter that evening and all was well.   The next morning there was a puddle of fuel under the AH exhaust pipe.  The unit was running but there was no fire in the burner can.

I replace the nozzle and adjusted the probes.....the unit looked like it had been service by the PO as the old nozzle and burner looked fresh.

Did a operational check other than the burning of the excess raw fuel which cause some smoking for the initial starting up all seemed in order.

So today I started up the AH and it heated up just fine.  Used the shower with no issues.  once the water temp cooled a bit the AH called for heat but the unit ran and with no burner ignition.  Fuel ran out of the exhaust pipe and puddled just like before. 

What would cause the ignition not to fire properly on the second call for heat?

Thanks
Steve

[pairodice]

I had exactly the same issue - not re-firing; Called Rudy Leggett (Trainer here) and he diagnosed it as a bad main board. It was expensive but now it works properly. Now if I can get the stinking overflow bottle to stop leaking (may replace it) then my system will be perfect... or not... lol

[Trainer]

Steve, Intermittent firing is caused by one of two components, Control Unit (brain box that runs the burner) and Ignition Coil. Having fuel coming from the exhaust pipe is caused by no ignition and sufficient fuel to run out.

The Controll Unit runs the ignition coil and fuel solenoid for 5 or 6 seconds when trying to fire the burner. So a bad coil will only have a short period of fuel to run out the pipe.

But a failing Control Unit that does not energize the coil and leaves the fuel on longer could give a good drip out of the pipe. So, my long distance SWAG (Scientific Wild A-- Guess) is the Control Unit. But this is only a guess and only replacing one or the other component will prove the correct solution.

If you can be in southeast Texas or in Baytown, TX, I can replace them till we find the failed unit and you would only purchase the conponent that fixed the problem.

All the best solving this.

[Latitude 28]

Pairodice,
Thank you for the reply!

Rudy thanks for your troubleshooting, that makes sense, as I have had similar issues with turbine engines. Also thanks for the offer to come by for some quality r&r (remove & replace....not rest & relaxation).  We are in FL and can't make it perhaps some other time.

[Trainer]

Steve, You may wish to call me especially if you are performing the tests. I am available from 8 to 8 central.

7 one 3 8 one 8 3234

[Latitude 28]

Been steadily working on this problem thanks to all for your offers to help.  Richard, called and put the bug in my ear to do the Beckett Mod as posted by Andy & Jean Harmon in the Wander Lodge Group (https://www.wanderlodgeownersgroup.com/f...hp?t=32866). Richard invited me over to see his mod to the AH he did a while back.  I was very impressed in what he had done as well as with the quality of the Beckett components.  Fast forward to this week...the mod is complete and the Beckett controller is running the AquaHot beautifully! 

A couple of pluses that put me into completing this mod;

• The terminal strip between the controller and the AH makes a great troubleshooting tool to break out voltages to each component.
  
• The controller is mounted away from the heat and vibration.
  
• The controller is easy to source and a solid built unit.
  
• The Igniter coils is a solid unit as well..(I provisioned for the Beckett coil as my original worked just fine).
  

My original thought was to use the AH wiring but the Beckett is wired differently albeit the same functions.  Once I put that idea to bed it was pretty straight forward to get it wired into the system.  Richard added a N.O. relay that controls the voltage to the motor.  I tried it as Andy's wiring diagram depicts and detected an audible rpm change i.e. voltage drop, in the blower motor during operation....highly recommend adding that extra relay and 14ga wire to the motor.  Speaking of the burner unit, the ground wire is in series with the fuel solenoid and flame sensor.  I separated the grounds and ran them dedicated to the Beckett controller.  

Steve

[smagown]

Steve, did you use the Beldon 8866 ignition wires?

[Latitude 28]

Steve
I used https://www.amazon.com/gp/product/B07CJZ...=UTF8&th=1.  However, I haven't connected the Beckett coil to the Webasco igniters as the original coil is still working. The Beckett coil will be a spare for the time being.

[Latitude 28]

Update on the Beckett Controller mod;

Happy to report the Beckett controller has been working flawlessly on our Aqua Hot.  The one caveat is the controller has no built in time delay circuit during shutdown. Simple work around is to wait till the burner blower quits during its normal cycle, then turn off the AH.

[Richard]

Aw shucks, after three flawless years on using the Beckett controller to run the Webasto, if failed to fire and the light went out. A little trouble shooting with the voltmeter shows the flame sensor to be faulty. Replaced the flame sensor with a spare and all is well.

BTW, and the reason for this post. When I first replaced the flame sensor, the Beckett controller was still “Locked”. You have to kill the ALL the power sources to the Beckett for 10 seconds to bring it out of lock mode.