Webasto problems - prime? Fuel intake level?

[Wee Venture]

So the Webasto on our 2018 R-31CB stopped working rather suddenly. It had been working flawlessly before that. And it has been used a lot, since we have lived on our boat for the past year, though our main source of heat while at the marina has been an electric heater, with the Webasto to supplement. The little green LED is giving an error code of one long flash after flashing rapidly about 5 times. This is apparently the code for failure to start.

I have two main questions at this point.
1) Does anyone know how low the fuel pickup is mounted in the main diesel tank? At the point the unit stopped working, I had 21 gallons of diesel left in the tank, as measured by the Volvo gauge and also verified when I filled the tank back up with diesel. I am curious how many gallons are left in the tank when the pickup for the Webasto starts sucking air. My working theory here is that the Webasto ran out of fuel.
2) How do you prime this unit? I replaced the Webasto fuel filter with a new one, took both fuses out for 10 minutes to clear the error code, turned the control to high and then turned it on. I could hear the pump ticking rapidly and then more slowly for about 60 ticks. It paused, ticked another series, and then shut down with the same error code. I repeated this about five times with the same result—no joy. I can shine a light on the fuel filter and see a bit of fuel in the bottom but the level is below the inlet and outlet holes, and there is no obvious movement of fuel into or out of the filter when the pump is ticking.

Any insight would be greatly appreciated. I’d rather not pull the unit if I don’t have to. Thanks!

John Bachelor

 

[Familyguy]

Let me state first that I have no technical knowledge of those heaters however there are two basic troubleshooting rules with any hydrocarbon based unit; Its either fuel/air or electrical (spark) and it sounds like you have done alot of troubleshooting on fuel. At this point I would explore ignition and I would not try starting it again until I Sussed that out because if the fuel is going in, you are flooding the combustion chamber which will make it even harder to start and maybe even result in the need to out the combustion chamber (Diesel won’t evaporate like gasoline)
Just my two cents, good luck.

 

[rheimb1]

That sounds like almost all diesel engines. If there is an air lock in the system the pump won't pump and that filter cup needs to be bled. How? I have no idea. Most have a line to bleed or some have certain pumping procedures or a hand pump located somewhere. Maybe the owners manual will enlighten you or just call the manufacture.

 

[knotflying]

I am not sure how long your pickup line is on your boat. On my boat, below 31 gallons in the tank I lose prime. I suggest you fill your tank and then prime the unit. It could take several tries before it starts to work. Usually after three times or so of no ignition you will have to reset the unit as you did before, remove the fuses and then reinstall. If the unit finally starts, you now know your minimum fuel level. If the unit does not start after this exercise let us know and we can then talk about troubleshooting.

 

[Chimo]

I didn't know my Wabasto had a fuel filter?? I don't see anything about it in the manual. Any hints?

 

[ALICE J]

When I first installed my Wabasto unit, it would not fire off. After about a dozen tries, I disconnected the fuel line going into the unit and started the cycle, apparently an air lock because after about three three cycles, I got fuel at the fitting, reconnected, and the heater started working. The fuel pump on the Wabasto only puts out a tiny spurt, so it may take a long time to fill the whole fuel line once it is empty. There is a place in Seattle that is very knowledgeable about the heater, give them a call, sorry I don't recall their business name. 😳

 

[Bruce Moore]

There is a place in Seattle that is very knowledgeable about the heater, give them a call, sorry I don't recall their business name. 😳

Sure Marine Service Inc.

Cheers,

Bruce

 

[Wee Venture]

Thank you all for the responses. The unit is still down, but I did a little more checking. I disconnected the copper fuel line on the pump outlet side. The copper tubing is about 6’ long and connects at the other end to the heater. About a half ounce of diesel fuel drained out, and then when I turned the unit on again (after pulling and reinserting the fuses) a little fuel dribbled out of the fitting with each tick of the pump. This tells me that it is not a problem with the pump losing its prime.

(Chimo, on my boat there is a rectangular black metal box near the main diesel tank with small diameter copper tubing going to the main diesel tank on one side, and to the heater unit on the other side. The cover to the box removes with four screws and inside is the fuel pump and the in-line filter. You are supposed to replace the filter once a year. You can order the filters from Richard at Ranger parts.)

The notion of an air lock is confusing to me in this context. On older diesel engines, the injectors couldn’t pressurize the fuel enough if there were air bubbles back in the line because of the compressibility of the air. The air was “locking” the injectors and keeping them from working. And of course some pumps will not self-prime after air is introduced. I don’t know how the Webasto burner works but it seems like if the pump is actually moving fuel, then temporary air in the line should get pushed out and not matter.

So on the one hand, it seems highly likely that the unit ran out of fuel since my main tank was down to about 21 gallons before I filled it up, but on the other hand it is apparently now getting fuel and still not starting. I guess it is time to call in the big guns. Thank you, Alice and Bruce, for the Sure Marine contact.

I am still open to suggestions if anyone has further insight. Thanks!

John

 

[rheimb1]

I always thought that the pump would push the fuel through too but I have found that even if you have just a couple of bubbles in the filter can/container/jar it won't pump. And that is on a diesel engine, on this heater it may be different, all I know is that it doesn't take much. I bet you still have a airlock in there somewhere. Please let us know the fix, I know we'll appreciate it.

 

[knotflying]

You didn't say how many times you reset the unit. I seem to remember that I had to go through the rest procedure at least three times before it would start again. Also, Have you determined what the code is telling you? The light will flash at different intervals giving a code. It will be two quick flashes and then count the slower ones. If you don't have the service manual PM me your e-mail address and I will send it to you.

 

[Wee Venture]

Ok everyone, today I went to the Seattle Boat Show and found a large booth run by Sure Marine (thanks again, Alice and Bruce) and spoke with a representative named Rick Waters (great name for the boating industry). I can’t recommend this place highly enough. Rick was extremely knowledgeable and patiently explained to me what the problem was and what to do about it. Even though he knew I was not currently in the market to be a customer, he spent as much time with me as I wanted, told me the steps to take several times, and showed me a Webasto unit that was like the one on our boat to use as a visual aid. I haven’t tried his solution yet but I am confident it will work.

He said the error code (one long flash) almost always means the unit has run out of fuel. The pickup tube in the main diesel tank stops significantly short of the bottom of the tank so as not to pick up sludge (and presumably to leave a contingency fuel reserve for the engine). Since we had only 21 gallons left in a 180 gallon tank, this is almost certainly what happened.

He said the Webasto is *not* self-priming. In spite of my telling him that some fuel dribbled out of the tubing when the pump “ticked,” he said that was just sputtering some air and a bit of dribbled fuel in a futile attempt to start pumping again, it was not seriously priming the system. He said you can tell when the pump starts truly pumping because the ticks quiet down and do not sound so metallic.

So here are the steps he gave me to get it working again:

1) Remove the fuse(s)—Or at least the 20A fuse—that supply the unit.

2) Disconnect the fuel line at the heater and put the end into a cup.

3) Disconnect the two wires going to the pump and find a source of 12V power. Alligator clip one 12V power lead to one of the pump wires but do *not* connect the other one. Polarity does not matter.

4) Take the other 12V power lead and the other pump wire and tap them together very briefly to make the pump tick. Do this repeatedly as fast as you want, but do not hold them together continuously because this will burn out the pump, which is expensive. During this process of tapping, the pump ticks should quiet down and sound less metallic.After doing this for perhaps five minutes, check the cup. It should have about 1/2” of fuel in the bottom.

5) Lift the fuel line back up from the cup and reconnect it to the heater, making sure hose clamps are tight. Hook the fuel pump back up to the original wiring.

6) Reinsert the fuse(s), turn the controls up to high and turn the unit on. If it gives the error code again, turn off the unit, remove the fuses, wait several minutes before reinserting them and then try again.

7) when it starts, there will probably be more smoke coming from the exhaust than usual. This will return to normal as the heater continues to operate.

I feel quite confident that this will solve the problem but I’ll let you know when I apply the fix. Thanks to all!

John

 

[knotflying]

Interesting procedure. I wonder why they don't have that procedure in the initial start up instructions in the manual. I will assume that Rick has had experience with this procedure and knows best, but it seems like a lot of work. Why not disconnect the inlet side of the pump and using a squirt bottle filled with diesel fuel pump it into the inlet, apply some pressure and fill the filter and while pumping turn on the Wabasto? Once ignition takes place send fuel down the pickup line, reconnect and start her up again.

Lets us know how it works out.m

 

[Wee Venture]

Webasto is working again! The problem was running out of fuel (even though there was still 20-25 gallons of fuel in the main tank), sucking air and losing the prime. The solution was a bit complicated but not difficult. I did *not* follow the procedure in my previous post that was given to me by a Sure Marine representative. That might have worked well for an application where the heater is easily accessible but it was completely unreasonable for our R-31. I actually pulled the fridge to get at the heater behind. But even then, the unit was not easy to reach. And the fuel line coupling was behind the unit and out of sight. It seemed to me that restarting the unit after running out of fuel could not be this difficult. I did appreciate Sure Marine though, and they did help me achieve a final solution.

So here is the procedure that worked for me, and the way I intend to handle this problem should it ever occur again.

1. Check fittings, hose clamps (make sure they are adequately tight) and make sure the fuel filter is mounted in the right direction (on my installation the filter was backwards for the direction of flow). The direction of flow is toward the wider end that has a cap that looks like a funnel. The “funnel” end should be oriented toward the pump.
2. Disconnect the copper fuel line where it exits the black box containing the pump and filter to go to the heater. Put paper towels underneath and hold a small cup under the fitting to collect any residual fuel as you disconnect it.(The other copper fuel line goes to the main tank and does not need to be disconnected.)
3. On our boat there are two fuses for the Webasto, a 20A and a 1A. Remove both and wait 30 seconds to clear the error code, reinsert the fuses and turn the unit on.

NOTE: There are two error codes that can be bypassed in this way, code 1 and code 0. Code 1 is five fast flashes followed by one long flash. Code 0 is five fast flashes with no interim longer flashes. Code 1 means failure to start and almost always means the unit has run out of fuel. Code 0 is supposed to mean the controller is not working properly but I am told that is almost never the case; it has simply determined there have been too many unsuccessful attempts to start and locked you out. Code 1 can be cleared by taking both fuses out for 30 seconds, reinserting them, and then turning the unit on. I believe you have to turn the unit on within a short period of time after inserting the fuses, perhaps 9 seconds. I also believe, for this error code, that you may only need to remove the 20A fuse, though both are ok.

After clearing code 1 a number of times, the unit will probably go into lockout with code 0. This is cleared slightly differently, with what is termed a “hard restart.” 1) Leave the switch “on” with the error code active; 2) Pull the 20A fuse first, then the 1A fuse; 3) Turn the switch off (this is unnecessary with controllers that have a small white illuminated push button); 4) Wait 30 seconds (at least); 5) Reinsert the 20A fuse first, then the 1A fuse; 6) Turn the switch on.

I found that with one or both error codes, they sometimes did not immediately clear with this procedure but if I simply turned the switch off, waited a couple of seconds, then turned the switch on again, the code would clear.

4. After clearing the error code and turning the unit on, hold a cup under the fuel line fitting where you removed the copper tubing. Wait a bit and you will hear the fuel pump ticking - several fast ticks and then more slowly (for about 64 ticks). It will then pause for awhile and do another 64 or so ticks. At that point it will throw the error code again. The heater won’t start of course, since you have the fuel line disconnected.
5. Observe what is happening. The goal is to repeat this procedure until you see fuel reliably coming out the fuel line fitting without spurts of air and bubbles. This will let you know that you have primed the pump, and at the same time have not been forcing fuel into the heater before it is ready to start and keep going.
6. After the system is primed, reconnect the copper tubing that goes to the heater and then continue cycling the pump (by resetting the error codes) till the unit starts. (And no more error codes occur!) On our R-31, I estimate that the tubing is about 6’ from the black box to the heater, and it took about 5 more resets after priming before the unit started.
7. Relax and have a beer or smoothie to help you enjoy the ambience of that new feeling of warmth!

John

 

[knotflying]

Good to hear that it worked out well.

 

[Chimo]

Thanks to everyone for a really interesting thread.

Does anyone happen to know the model of Wabasto heater I would have in my 2017 R 25 SC? I only received a manual for the Evo Top and not for the unit.

 

[Wee Venture]

Our boat is not the same model, a 2018 R-31CB, but for what it’s worth, our Webasto model is the Air Top Evo 40. The controller pad is the Air Top Evo M (as written on the lower left hand corner).

 

[Chimo]

Our boat is not the same model, a 2018 R-31CB, but for what it’s worth, our Webasto model is the Air Top Evo 40. The controller pad is the Air Top Evo M (as written on the lower left hand corner).

Many thanks!

 

[Hamster]

The Webasto website has additional manuals and videos on their heaters and controls. I found the additional information quite useful, particularly for the controls. https://www.techwebasto.com/