webasto thermo pro 90 not starting

[pfishuk]

hi all, we've been on our live aboard for 3 weeks now and the boiler has just started playing up. cant get it to start up at all today, checked fuel and lifted fuses as suggested in the user guide. but no joy - does anyone have anything else i can try?

[system 4-50]

Is your fuel level high enough for your pickup? 

Can you give some idea of your level of expertise?

[Chewbacka]

How did you check fuel?

[pfishuk]

Hi my expertise level is pretty much novice - checked fuel with dipstick provided by last owner, 

 

update - managed to get it going - a strange combination of removing fuses and turning it on and off again at the thermostat control. someone at the marina suggested it might have cut out due to the electrics tripping when we had the dishwasher on - is that a possibility or do i need to investigate further. 

[Tony Brooks]

Also how sure are you that you always keep your batteries very well charged. As livaboards with a Webasto & dishwasher for heating I suspect you will need at LEAST four hours engine running at a reasonable speed per day and 8 to 12 at weekends or using a 20 amp plus battery charger form the mains 24 hours a day.

 

Battery voltage reading while its trying to start will help.

 

 

[Sea Dog]

1 hour ago, pfishuk said:

do i need to investigate further. 

A couple of things to bear in mind for future reference:

 

The fuel take off in your tank should be a little way above the bottom to  ensure your heating can't run your tank to empty and leave you with no propulsion. This means a low fuel level might see you having problems with your heater even if you think you have some in the tank.

 

These units can be very sensitive to low voltage so if your batteries are a bit down, they won't start. If you're not sure, start your engine so the alternator is charging, or make sure your shore supply charger is on, then try the heater.

 

Hope  that helps.

 

[system 4-50]

1 hour ago, pfishuk said:

Hi my expertise level is pretty much novice - checked fuel with dipstick provided by last owner, 

 

update - managed to get it going - a strange combination of removing fuses and turning it on and off again at the thermostat control. someone at the marina suggested it might have cut out due to the electrics tripping when we had the dishwasher on - is that a possibility or do i need to investigate further. 

Is it possible that power to your webasto was cut off while it was running or while it was still powering down?  This is a big no-no for my webasto thermotop C, I don't know if it applies to your model and your wiring configuration.

[pfishuk]

i think that might be the case yes - the electrics tripped as i say and then we noticed later that day the heating was not coming on. it was the inverter that tripped off not a fuse on the main board. 

[pfishuk]

forgot to add - we are marina based currently, plugged in all the time to the marina mains at 16amps. 

[Detling]

The Webasto runs off 12 volts not 240 so should not be affected by inverter tripping, When the inverter tripped the charger will also have cut off, this will mean the battery was having to supply the power as it was no longer coming via the charger. This should make little difference for a few hours but eventually the batteries will reduce their voltage and the webasto will shut down. If however the batteries are knackered then the voltage will fall rapidly and thus shut off the webasto.  

[Chewbacka]

22 minutes ago, pfishuk said:

forgot to add - we are marina based currently, plugged in all the time to the marina mains at 16amps. 

Possibly cheaper to use electric heating rather than diesel.

For the future (not sure about your specific model) but if a Webasto unit attempts to start a few times and fails, it ‘locks out’ and will not start until reset.  The reset is to remove the fuses and wait 20 seconds, then put them back in.
 

If you run the unit from your batteries and backed up by the charger, then if external power is lost the battery will discharge and when the voltage reaches a critical level the Webasto will safely shut down, but if you power off whilst running it will not be happy..........

[pfishuk]

how would i know if my batteries were knackered? - boat is 2 years old from new, how long should they last?

 

 

[WotEver]

35 minutes ago, pfishuk said:

how would i know if my batteries were knackered? - boat is 2 years old from new, how long should they last?

They’ll last anything from a few weeks up to a few years, depending on how well they’re looked after.

What is their voltage an hour or two after taking them off-charge? What is their voltage a few hours later (still off-charge)?

 

Do you have any battery monitoring at all? BMV, SmartGauge, ammeter?

[pfishuk]

No idea how to even start with that. If I disconnect mains how do I find battery charge 

[WotEver]

Tony Brooks has a great site with loads of useful info on it. This section would seem to be particularly pertinent for you:

http://www.tb-training.co.uk/MarineE05.html#BATTERY CARE AND SERVICE

[Tony Brooks]

And in the electrical notes there are diagrams showing how to connect a voltmeter to batteries