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Topic: Aquahot rebuild, now problems (Read 476 times) previous topic - next topic

Aquahot rebuild, now problems

1999 U320 coach.  Put some new parts in the Webasto burner.  New bearings, seal for fuel pump, new electrodes and seals for burner head openings.  The Aquahot starts and ran for about an hour then stops and light by sink goes out.  Wait about 15 minutes and restart.  Runs for about 15 minutes and stops just as last time.  Reset switch and restart, has trouble igniting but does and runs for 5 minutes and stops again.  Smokes pretty bad on all 3 starts (video in zip file).  Also attached 2 video of monitoring the motor voltage at C2/C5 at controller. Also video attached.  It appears that the 12 Vdc drive motor runs but not at a constant speed.  C2/C5 voltage seems alright at 13.2 Vdc +/- 0.1 Vdc.  It also appears that the RPM is close to 4500 rpm at about 13.1 Vdc but slows down and the voltage goes up to 13.25 Vdc.  Also from the 2 burner videos (attached Zip) the sound is very different.  Bad motor or rubbing?  I spun the motor and fan before putting all together and everything appeared to be loose with no interference.  The fuel pump pressure was checked and was 145 psi but as the motor slows down I am sure the pressure is less.  Any ideas or is the motor just bad or failing?  Getting ready for trip and want it to work.  YouTube videos here if you don't want to UnZip.  https://youtube.com/shorts/bd7g_MZDPfM?feature=share
https://youtube.com/shorts/VThWt3VBFB0?feature=share
https://youtube.com/shorts/1J5alQZ3c3s?feature=share

Re: Aquahot rebuild, now problems

Reply #1 –
Wtih the motor slowing down and new bearing in place, bad motor.  When replacing the motor, clean the combustion chamber and the U-channels that the chamber inserts into.  Clean flame sensor and chech ignition points gap.  You should be good to go

Contuning to run this way is NOT recommended.  Electric element should be okay but only 1/10 the capacity of the burner.

Re: Aquahot rebuild, now problems

Reply #2 –
My opinion is whatever Rudy said!
In two and a half years I have had no issues with my aqua Hot and I am dreading it. I run it all the time and so far it hasn't let me down except for when mistakenly I left the switch off. I've got a new racor filter element for the filter I put in a few years ago and a new nozzle ready to go, but so far I run it all the time and it just works. I'll be giving Rudy a call for sure if it stops.
Hope you get it sorted out.

Re: Aquahot rebuild, now problems

Reply #3 –
Thanks Rudy.  Will report back as repairs are completed and restarting system.