[Archived]

Start with change the nosle and clean photo cell.

[Kevin]

OK, I’ll try that

[Archived]

Jerry, I am not at all familiar with the AquaHot, but what might make noise is the internals in the Webasto. It could be the pump or fan blade or something associated with that so when you open it up to get at the Webasto to check the nozzle, turn it on and you should be able to hear the origin. It won’t spray fuel or ignite right away. Disconnect the leads from the coil and when (if) it goes into the spray mode you will see the pattern and if it is atomizing the fuel with a nice spray you can rule out the nozzle.

[Archived]

If it doesn’t spray out check the overheat fuse (two white leads) for continuity, if open the fuel solenoid will not opening to allowing the fuel to spray. The other Thermostat to check is the temperature limiter (green and green wires) both of with at under the plastic cap on top of the flame chamber. If it is not closed no voltage is getting to the fuel solinoid either. These two fuse/thernostats are wired in series betweeen the C4 terminal in the control box to the fuel solenoid and then on to the photo cell then to C6 of the control box.

[Richard]

OK, I changed the nozzle and no difference, other than the rattling may have been the metal plate that the light sensor is in.

Now, the motor runs and sounds right, but no flame. I’ll check further.

[Bernie]

The photo cell plate is suppose to be loose, it kind of floats.

[Bill]

I had a weird intermittent problem with my Wabasto and found a troubleshooting guide online. I was able to determine (after many successful tests) that one of the connections in the fuse box was loose and not showing continuity. Just an every so slight tightening of that fuse (if that’s the right word) corrected the issue. I even went so far as to remove the burner assembly and turn it on. Wow! You should see that flame when it fires up correctly (don’t try this at home!). My wife says I have lost my mind. But, armed with that info, I could see what should happen and it helped me figure out what was not happening. I actually replaced the nozzle (not the problem), the spark generator (not the problem), the electrodes (showing signs of wear but not the problem), checked the fuel filter (not the problem) and cleaned every connection I could find (not the problem but likely not a bad idea either). I had checked all of the fused connection links and they worked. After the 3rd or 4th attempt to find the intermittent issue I checked them again and one failed. I traced the connection back to where it entered to top of the Webasto and found I could turn it by hand. Hummmm….. Got a wrench and tightened it down ever so slightly and I have not had an issue since. Oh, I just realized that I forgot to add that I bought a new “brain” for the unit since a test “brain” made it work (once). While it ended up not costing too much (the brain), I spent way too much money on a problem which turned to simply be a loose connection.

[Bernie]

I went through test procedures found on the internet tonight, the electrical box “brain box” checked fine, and all wires going to the Webasto. Checked the coil, hooked up separately, and it worked, But I can’t hear it arcing when it is installed. So, I’m not sure if the photocell is working properly. I checked it best I could, It does change ohm readings when covered and uncovered, but not sure what is good or bad.

I took the return line off, started the motor, and no fuel came out. So, I’m looking there next. Fuel filter is full, no water in bottom of bowl. I guess could be the fuel pump.

Bill, what did the wire go to that you found loose?

[Greg]

Jerry if you need help call John he was Aqua hots head tech he now runs his own repair shop he is the best , he has helped me here’s his number cel 1-970-518-3085 he goes all over the country fixing them …

[Archived]

Jerry

I will repeat you are not get 12volts to the fuel solenoid. If you pull the large connector off of the control box and do a continuity check with your DVM between C4 the on to the right of the top empty pin and the C6 the second to from the left on the lower part you should see a low ohms reading or a buzzing if you use that function.

The other thing you can do is to unscrew the four screws holding the coil down under there you will find the wires to the coil disconnect one this will prevent the ingiting of the fuel. Now with the motor running apply like normal apply 12 volts to the back solenoid terminal and this should open the solenoid and you will see a spray of fuel. If this doesn’t happen and with a good noosle you most likely have a bad solenoid, I seriously doubt you have a bad fuel pump. You should be able to hear and or feel the solenoid working. The photocell is what tells the control box to stop the spark, you have a flame.

[Archived]

All good info…. If the solenoid checks OK, then the brain is subject. There are little relays in the brain box that control the functions.

I just had to take one apart….

[Archived]

Jerry,

There are 3 ( I think) fuse/sensors under a cover on the top back of the burner housing (mine real old yours may be elsewhere). Each fuse has 2 wires that lead to a block with a series of connections. These should show continuity if working. Mine did the first time I checked but after working for a short period it unit failed again and one of the connections did not show continuity. I was able to turn the unit with my fingers. A slight tightening and it has worked ever since.

[Jerry]

I found the problem today.

After not getting any fuel, And after all electrical was verified, and the “Brain box” was verified., I finally took the cover off the Webasto. Then, I found the problem. There is a plastic coupler, sort of a gear on the shaft of the motor that drives the unit which has another gear, plastic also, and it was broken! That was what was making all the noise I mentioned in the beginning of this thread. The broken gear also caused the motor to mess up, and not provide power to turn the fuel pump.

It now works like brand new! Thanks to Paul Lance, an Aqua Hot repair guy who was close by at the FMCA rally in Perry, Ga. Which I live close by. He had all the parts I needed in his van.

I also learned how to stop one from smoking, if anyone needs to know, let me know.

Peter, Paul works along with John, the guy you suggested earlier!

[Dick]

Jerry don’t tease us, how do you get one to stop smoking?

Greg

[Archived]

Greg,

The plate that holds the Photocell flame detector also acts as a seal, that’s why it is loose, held by a snap ring, so it can seal against the burner can. If it is warped any at all, or not completely flat, it will allow air to leak by. Also, the rubber groments that insulate the wires going throught the cover, must be soft and pliable, because they also seal out unwanted air. And the “O” ring that goes around the Webasto cover, must seal well too.

Too much fuel creates white smoke, and too much air leaking by where it’s supposed to go, black smoke.

However, they all will pretty much puff a little smoke at start up, just the nature of the beast.

While running though, they should not smoke.