Webasto Airtop Evo 3900 problem

[aquaholic]

The system was installed in 2009 by the previous owner, had a fault code flashing 12 times, so called a local dealer in who came down removed the unit, serviced it, fitted new burner and few bits that I cant read on the reciept.....and refitted it. Cost £390

2 months later with it only being used twice its now flashing twice, which the manual says is a flame failure. thought i would ask here if anyone has had this problem before I go and pick more money off the money tree in the back garden

I keep being told these heaters are fairly trouble free, wish i could find one!

 

[nigel1]

Just some simple checks:
Do you have full battery voltage, they dont like low volts

Can you hear the fuel pump operating

Check fuel supply to unit

Check exhaust not block with condensate, (disconnect exhaust pipe from bottom of the unit

 

[Steve Clayton]

Flashing 2 is fuel problem.

If the fuel has run out, and you've topped up then it can take maybe 7 or 8 restarts for the new fuel to completely prime the system.

As per Nigel you should hear the fuel pump; gentle click-click every few seconds.

Close to pump should be fuel filter, genuine webbie filter is a small sealed canister, could be poor throughput and cause of problem. I've replaced with Halfords in-line plastic see-through filters for about £3.; works fine for me (some say using the wrong filter can upset the balance). Straightforward to change but note my first comment if you change it.

 

[David2452]

Flashing 2 on the Evo is flame out on more than three attempts i.e. the flame has gone out whilst it was running and it could not restart, can be fuel, flame sensor or a burner insert, at least they are the most likely candidates. Did the dealer who serviced it last time set the Co2 up, they cetainly should have if a new burner insert was installed, that is to say did they poke an anayliser up the exhaust and fiddle with the control unit (if you were there to see it) I ask because at that age it really shouldn't have needed a burner unless it was getting poor fuel or was set far to rich though the owner was unlikely to have set the CO2 when he installed it so that could have led to it prematurely needing a new burner insert. 12 flashes is a permenant lock out which can be reset by removing the fuse and replacing it, mind you there's not much point until the fault is cleared. Had it been recieving low volts or has a fuel pump fault other fault codes would be present. The evo is not that fussy about voltage and the glow pin pulses rather than drags contant amps from the battery, 10.5 - 11v at the unit is enough to start one comfortably if the rest of the heater is OK. As for reliability, they are if installed and set up correctly and given decent fuel, run once a month for an hour and a simple anual service.

 

[aquaholic]

Thanks for replying, the boat was used as a live a board for a year prior to us buying so I am assuming the heater had a fair bit of usage which is why it may have needed a new burner and the bits and pieces. Power is fine, three new batteries in October, multi phase charger etc. will check fuel but sure it's around the half way mark. He did set up the co2, and seemed very knowledgable, he recommended a dedicated tank in the future so I could run the heater on white diesel, could the red diesel cause a problem?

 

[David2452]

A year as a live aboard should present no issues for a well installed heater with good fuel, the fuel issue the local dealr mentionedmay be an issue, if you are still using high sulphur fuel, if you are in an inland marina and now getting ULS red then that is somewhat negated. Even so if the CO2 is set close to the low limits of spec and the heater is run hard then provided the standard sulphur fuel is good quality there shouldn't be issues this soon. Off to service heaters now so will not be able to reply until this evening.

 

[catlotion]

We had a similar experience on our Airtop 2000. New burner fitted and full service but still refused to start. The fuel pump was ticking and fuel was moving in the hose.

It turned out the feed hose before the pump was partially blocked so not enough diesel was reaching the pump. You couldn't even blow through it...

Got a new bit of fuel hose from motor spares shop for £3 (tank to pump) and everything fine...

 

[aquaholic]

We had a similar experience on our Airtop 2000. New burner fitted and full service but still refused to start. The fuel pump was ticking and fuel was moving in the hose.

It turned out the feed hose before the pump was partially blocked so not enough diesel was reaching the pump. You couldn't even blow through it...

Got a new bit of fuel hose from motor spares shop for £3 (tank to pump) and everything fine...

Sounds like an avenue to explore, what was hose blocked with?

 

[catlotion]

I don't know - I didn't think it was worth cleaning out. We had a suspected fuel bug issue last year so I presume it was related to that.

maybe just try removing that section and see if you can blow through it - at least you'll eliminate it if it's ok. I went round in circles for a while without seeing the obvious!

 

[nigel1]

Flashing 2 on the Evo is flame out on more than three attempts i.e. the flame has gone out whilst it was running and it could not restart, can be fuel, flame sensor or a burner insert, at least they are the most likely candidates. Did the dealer who serviced it last time set the Co2 up, they cetainly should have if a new burner insert was installed, that is to say did they poke an anayliser up the exhaust and fiddle with the control unit (if you were there to see it) I ask because at that age it really shouldn't have needed a burner unless it was getting poor fuel or was set far to rich though the owner was unlikely to have set the CO2 when he installed it so that could have led to it prematurely needing a new burner insert. 12 flashes is a permenant lock out which can be reset by removing the fuse and replacing it, mind you there's not much point until the fault is cleared. Had it been recieving low volts or has a fuel pump fault other fault codes would be present. The evo is not that fussy about voltage and the glow pin pulses rather than drags contant amps from the battery, 10.5 - 11v at the unit is enough to start one comfortably if the rest of the heater is OK. As for reliability, they are if installed and set up correctly and given decent fuel, run once a month for an hour and a simple anual service.

Thanks for your input David, nice to see an expert offer advice.
I mentioned exhaust blockage as a couple of years ago, having just taken deliivery of my boat, I was having problems with the Webasto Airtop 5000.
PO had stated it was installed less than a year ago by approved Webasto installer. Ignition was very intermittant, when it did manage tio go, lots of black smoke, but usually was getting a flame out error.
I pulled the exhaust off and found a fair quantity of diesel in it. I was thinking that was due to the non ignition. But after tracing the fuel system, found that the installer had taken the fuel supply from the top of the engine pre filter housing. This is pressurised when the engine is running and was pushing fuel past the webasto fuel pump to the burner, flooding the unit and the excess draining into the exhaust.
Stripped down the unit, cleaned, fitted service kit, re-routed fuel supply to be direct from fuel tank, and no more problems since.
Not very impressed with the initial installation

 

[aquaholic]

Thanks for your input David, nice to see an expert offer advice.
I mentioned exhaust blockage as a couple of years ago, having just taken deliivery of my boat, I was having problems with the Webasto Airtop 5000.
PO had stated it was installed less than a year ago by approved Webasto installer. Ignition was very intermittant, when it did manage tio go, lots of black smoke, but usually was getting a flame out error.
I pulled the exhaust off and found a fair quantity of diesel in it. I was thinking that was due to the non ignition. But after tracing the fuel system, found that the installer had taken the fuel supply from the top of the engine pre filter housing. This is pressurised when the engine is running and was pushing fuel past the webasto fuel pump to the burner, flooding the unit and the excess draining into the exhaust.
Stripped down the unit, cleaned, fitted service kit, re-routed fuel supply to be direct from fuel tank, and no more problems since.
Not very impressed with the initial installation

Is my post being hi-jacked ???
seriously, thanks for all your input.

 

[David2452]

Thanks for your input David, nice to see an expert offer advice.
I mentioned exhaust blockage as a couple of years ago, having just taken deliivery of my boat, I was having problems with the Webasto Airtop 5000.
PO had stated it was installed less than a year ago by approved Webasto installer. Ignition was very intermittant, when it did manage tio go, lots of black smoke, but usually was getting a flame out error.
I pulled the exhaust off and found a fair quantity of diesel in it. I was thinking that was due to the non ignition. But after tracing the fuel system, found that the installer had taken the fuel supply from the top of the engine pre filter housing. This is pressurised when the engine is running and was pushing fuel past the webasto fuel pump to the burner, flooding the unit and the excess draining into the exhaust.
Stripped down the unit, cleaned, fitted service kit, re-routed fuel supply to be direct from fuel tank, and no more problems since.
Not very impressed with the initial installation

Yet another example of a bum install, I despair sometimes at stuff I see, occasionaly by so called dealers.

 

[catlotion]

tell me about it - most of the stuff on our boat was obviously installed by a blind monkey. That's ex-charter boats for you though I suppose.

Slowly rectifying the mess though...