[Pluto]

Hello all, my wife and I recently purchased coach 525 and I am trying to work out a couple of bugs on it.  Last night our aquahot was not coming on so I went to check it out and it was leaking diesel from around the burner and all over the bay floor. 

Our previous coach, a foretravel grand villa, did not have the aquahot system so I'm not familiar with the system at all.  On top of that the unit in our coach has been modified with the "becket system" which I am also not familiar with, adding to the complexity of diagnosis. 

Between getting ready to move to Arizona from Florida in two weeks, trying to figure out how to remove or rear ac system and trying to get someone to look at it and a number of other things going on, it's been difficult for me to keep everything under control.

If anyone can point me in a direction on how to diagnose our Aquahot issue I would be very grateful.

Thank you,
Tyler Phillips

[Trainer]

Tyler, Contact Richard Entrekin on this forum. He has that burner and can help you.

[encantotom]

where in arizona are you moving to?

tom

[Pluto]

Thank you, I will try to get in touch with him.

We're moving to Page, AZ.  I work for the NPS and will be there working at Glen Canyon NRA.

[Latitude 28]

Hello Tyler,
Sorry you're having an issue with the AH....let's go through some voltage checks.  

Before we get started.  On the Beckett Panel in the AH bay....since the fire sequence obviously did not happen like it should we will need to reset the Beckett Control there is a power wire connected with a blue bullet connector (marked with yellow labels) disconnect that wire and reconnect after a few seconds.  you will hear a slight relay click from inside the Beckett controller....that does the reset. Now turn the AH on and during the initial 20 sec start up check for 12vdc on the ignition portion of the terminal strip....see picture and during the same start up move over to the blower motor and check 12vdc on those terminals.  Did you have 12vdc on the ignition?  Did you have 12vdc on the blower motor?  Was the blower motor running?  If yes to all the above then that's good.  

The Beckett mod does the exact same functions as the original AH controller and ignition coil after that everything else is standard AH troubleshooting.   I'll give you a call in a bit.
   
   

[Pluto]

We were able to make some progress on the AH system and even thought we had it fixed for a few minutes. Thanks to Steve and Richard walking me through the process of elimination we were able to confirm the system was working correctly. However, upon removing the burner I noticed the the nozzle was continuing to leak fuel even with the system off.

We read through the manual and found how to check the fuel solenoid using a 12v power source. The only thing I could think to use at the time was the battery in my truck so I removed it and ran wires to the solenoid terminals. The solenoid clicked like it was supposed to and after cycling it a couple times the fuel quit leaking from the nozzle.

I put the system back together and it fired right up like normal. The system smoked like a freight train for a few minutes until it burnt off all of the excess diesel fuel but then ran fine and reached temp. Unfortunately, as soon as the system shut down after reaching temp it began to leak diesel again.

I'm hoping that if we replace the solenoid it will fix our issue. If anyone has experienced this before and was able to fix it I would love to hear if the solenoid solved the problem.

[Pluto]

I got back into the system after work and think I found the source of the leak. There is a plunger inside of the fuel solenoid shaft that is activated by 12v being applied to the fuel solenoid. When 12v is applied to the solenoid the plunger is pulled back and allows fuel to flow from a port, when 12v is removed the plunger returns and seals the fuel port with a rubber tip.

I was able to operate the solenoid and plunger by removing it from the burner head and applying 12v. The fuel valve assembly works as it should so maybe it was getting stuck and allowing fuel to pass by.

I put it back together and tried to fire it up. The burner fired off instantly but only ran for about 5 seconds before shutting off. We tried firing it up again but got nothing. I tried tracing wires using the different diagrams that we have but couldn't figure anything out. Now the beckett unit smells like it's cooked. I have no idea!

So now we're considering just replacing the entire unit. We are full time and having a new unit installed might be the best option for us. The unit has worked well for 25 years but everything has a finite life span.

Does anyone know what it would cost (approximately) to have a new unit installed?

[Richard]

Hang on.

The most likely scenario is that you lost prime when taking the solenoid in and out. Try resetting the Beckett and starting it up. You may have to do that two or three times.

Second, follow the diagnostics again, measuring voltages as Steve showed you.

You are going to fall over at the cost of a new unit.

[RussWhite]

What Richard said! Keep at it and find the problem. I even replaced my boiler and wrapped it in copper tubing for a fraction of the cost of a new unit. One step at a time and lean on the group if you need to. I understand it is critical for your coach, but just slow down and dig down to the root cause. Just my opinion. Russ

[Latitude 28]

Since the unit is firing up the voltages are most likely going to be fine on both the igniter and blower motor. What Richard said about air in the system is likely whats going on.