Tony Brooks

Or they worry some ham fisted bod will bend them.

It sounds to me as if you are a prime candidate for a properly cocooned permanently installed marine generator that hopefully you can run outside the 8 till 8 time slot without annoying other boaters. Then, as long as its powerful enough you would never need to worry about charging again. However I would not want it to run when no one is attending the boat. This will not be a cheap option, probably costing over £10,000 professionally installed but will meet your electricity needs. This will not preclude changing to lithium batteries at some point in the future.

Sorry but this is going to appear very hard and heartless. Or take a hard look at the electrical equipment and decide which are vital and which are not much more than nice to have. That may get the demand low enough to do a good long once or twice a week charge and let solar do the rest as best it can. A 46" TV and valve amplifier are far from essentials and I bet you have more like that. All would be perfectly doable if you have a shore line but you seem not to so you must make adjustments to your lifestyle to accommodate what is possible rather than try to generate enough electricity in winter to live as you want to because given your restraints that is going to be almost impossible. I would be very wary of a generator that may run while you are away from the boat for many hours.

On pumped wet systems like this the main pipe runs are usually at or close to floor level while the heater is often mounted above the uxter plate so may be 2ft or more higher. This is a sure fire recipe for an airlock in the horizontal pipes that leave the heater. It is even worse if there is a slight uphill slope leaving the heater. If I were fitting one I would fit an air bleed pint at the highest point in both horizontal runs but the hot outlet one is probably more important. That is unless a vent is fitted at the highest point, not a filler, an open vent. To say any more needs a carefully drawn diagram showing the whole system and exactly the angles and how the pipes run.

This page shows the glow plug kit and the burner & glow plug assembly so that might give you a clue as to where to start looking. https://www.cabin-connect.co.uk/ProductGrp/webasto-thermo-top-c But I would have hoped that this would have been in the "manual" supplied with your heater. Now you add a vital bit of information. That suggest an over heat shutdown which in turn suggest lack of water circulation so:- Lack of water, airlock, valve turned off, restriction to flow and so on. With that last bit of information the TRV might be an issue. Why oh why do we have to try to drag info out of people with [problems or only get fed vital bits of info in dribs and drabs.

The TRV will not be an issue re starting. It might become an issue if it restricted the flow enough for the heater to eventually overheat. I think the fuel flows into a sport of gauze covered pot in the modern heaters (unlike Webastos of the late 60s) so I can't see why you should expect to see fuel at the exhaust outlet. I think I would measure the voltage at the glow plug terminals when it is starting and if you get in excess of 12V there take the plug out, connect the wires and try to start it to see if the plug glows brightly enough to ignite diesel..

That is the way to do it. During that initial half hour or so I talked about and it may be longer if you are a heavy electricity user, the batteries will take everything the charger and solar can throw at it because the heavy current draw will pull both sources voltages down to below regulated level so you maximise the output of both. after the charging voltage has hit (say) 14.2 to 14.3 it means the batteries are demanding less charge so turn the charger off and leave the MPPT to finish the job. There is one further consideration in that chargers and solar controllers that drop into to a float voltage in all likelihood do it too early so the general advice is that when the source drops into float is turn that source off for a minute or so and then back on (if there is no switch between the panel;s and MPPT just cover the panels for a short while. Then whatever the source is (apart from a standard alternator) the charging voltage will jump back up for a while. I think that I were in the OPs situation I would experiment with setting the float voltage on the charger and the MPPT to 14.4 volts so it never actually dorps into float but if the charger as to be left on 24/7 it would be vital to set it back to 13.6 to 13.8 volts. Otherwise you will damage the batteries.

I don't think so, especially as we are now running on low sulphur fuel so far less sulphuric acid produced during combustion. However I would attempt to organise my oil changes so I got fresh oil in for periods where the engine would only run now and again. As long as the OP has been using a detergent oil and has been doing regular oil and filter changes I doubt running for another 50 hours now and again will make any measurable difference to the engine's longevity or war rate.

Perhaps it is easier to say that whichever charge source be it alternator, inverter/charger or solar that has the higher voltage at any one time will do the majority of the charging (after the first half hour or so). I have heard that some suggest that the load terminals can be sued to charge the engine battery but I am far from sure about that. I am with Chewbacka, ignore them.

First it is VITAL that you grasp that after the first half hour or so of charging it is the BATTERIES that control the charging current they will accept (at any given voltage). Before that half hour or so is up the batteries are asking for more current than the charge source can supply so two things happen. The charge source runs at maximum output and the charging voltage is depressed. The voltage gradually climbs to the source's regulated voltage as the batteries charge and the current thy demand drops. If you are charging from two charge sources then during that first half hour or so the batteries will demand so much current that both sources will supply the maximum they can but eventually the charging voltage from both will rise until one or the other reached its regulated voltage. Then, at that point if one charge source is set slightly higher teh lower one will appear to shut down. It won't actually shut down and if you turned on a heavy electrical load it would start providing charge again until you turned the load off. By an hour ago on this nice bright day (in the south) there is every chance your solar controller has decided it should be in float mode. That means it has reduced its charging voltage to prevent it damaging the batteries so it is probably regulating at about 13.8 volts. Upon start up the charger/inverter probably sets itself to a regulated voltage of around 14.4 volts while it decides what it needs to do. (Very soon I would expect that also to go into a float voltage at which point the MPPT might or might not display a higher charge). Now the charger at 14.4 volts will basically do all the charging because at 14.4 volts the solar can not push any current into the system with only 13.8 volts. This is normal. I do not think you have doe anything wrong, the system is behaving exactly as I would expect. You probably have very well charged domestic batteries that will only accept a low charging current. You do not need to do anything. Try it whilst getting light tomorrow and the situation may reverse itself. All perfectly normal.

To paraphrase Gibbo - anyone who uses 12V to generate heat is an idiot. If you have a shore line and battery charger running 24/7 then as long as the charger can cover the heater load then it will probably work. If not will the thermostat also start a generator to recharge the batteries. Basically the amount of heat you want is proportional to consumption of charge so to make a meaningful difference to internal boat temperature any heater that has a sensibly low consumption will not do the job. Electric heating will ruin batteries PDQ. Probably the easiest way to achieve what you want would be a gas fired warm air blower system.

Now you tell us you have loads of solar that 13V when trying to start looks perfectly plausible as long as there was reasonable daylight and in my view should be enough to start the heater. Paragraph 4 - No, No, no. The batteries will not be around 14 volts. You may well have 14 volts being delivered by the solar system but that is different to battery voltage. Battery voltage is only a reliable indicator of degree of charge when the batteries have been off charge for many hours and no load has been applied or they are off charge and a reasonable load has been applied for a few minutes. However 14 volts at batteries and 13 volts at Webasto fuse WHEN STARTING should be plenty to start the heater but that indicates a 1V voltdrop between batteries and fuse which is far from ideal. If the 14V and 13V were taken with different amounts of daylight then you can not compare or use the readings.

Sous as if you may now have some form of lock out - have a read of post number 14.

Well, unless a charger was on or the engine was running that 13V is highly suspect. Are the batteries in your meter fairly new? It is even more suspect if the unit was trying to start at the time. 13 volts would be obtainable on a set of batteries that had just come off charge as long as no load was applied to them but when the heater glow plug load was applied the voltage should have quickly dropped to around 12.7 to 12.8. After four attempts to start it should definitely be around those values. If the wiring between the heater fuse and heater itself was provided by the manufacturer then we can assume whatever voltage was there would also be reasonably close to the glow plug voltage but if you purchased the connecting cable then it might be undersized for its run length. Then it would cause voltdrop so the glow plug may not get hot enough. It would also give a low voltage at the heater itself and there in may be a problem. As I understand it the under voltage cut-out value for marine units is set a little lower than automotive ones so if yours is an automotive unit AND if you have discharged batteries or undersized wiring the under voltage cut-out could be operating. Now you have fuel at the heater how much smoke does it make while trying to start? No smoke = no fuel or such a low voltage the glow plug can't even vaporize any. Smoke but not much = glow plug voltage low Clouds of smoke = may be too much fuel build up or some other fault (can't help you here as I hate the things and would not have one) Not an Ebay bargain by any chance! If so what other answer were you expecting!