NMEA

I Despair.

Yes there is an hour counter in the software. Your boat fitter, like most boat fitters is clueless Revs are a no no on evaporator heaters.

What he said, this is the usual behaviour of a unit that has insufficient radiator load due to poor initial system design and is the prime reason these things cycle like this and coke up prematurely.

Does it have a dedicated stand pipe of the correct bore or is it tapped into a filter or teed off another line.?

Do you have a proper 2mm bore dedicated dip tube and 2mm bore fuel tube all the way from the tank? I assume you have checked the voltage at the heater during start up. Even a small amount of air in the supply tube will be enough to cause issues.

Copper is less durable but has antibiotic properties. Inox stainless is much more durable but does not, we rarely fit ss ones to inland craft but conversely fit them almost exclusively to sea going craft. It seems to be a cost issue more than anything.

If you buy a filling loop kit from Screwfix it will have a gauge, pressure relief valve et all with it and screws directly onto the pressure vessel. Bottle vents suit any system and are available in 15mm compression fitting and 1/2" BSP.

Yes they've not really used the right word, what you need is a bottle vent.

I have no Idea why you would fit an Air Admittance Valve, they are for drainage and syphon breaks in skin fittings, exactly the reverse of what you want to achieve so am confused. We normally fit 3 bar Pressure relief valves, they usually come with the filling loop kit anyway, charge the system to 0.75 - 1 bar cold and expect it to run at anything up to 1.5 bar hot. A bottle air vent like this BOTTLE VENT is useful to install close to the heater outlet, or a Spirovent, but I usually reserve them for larger more expensive systems as they are about twenty times the cost of a bottle vent.

I find it difficult to believe there is no pressure relie valve but if not then they are simple to fit. Generally when installing new Kabolas I power them via a small dedicated inverter which eliminates shore power loss issues and keeps the system running.

If you are getting flash codes you have voltage so it will not be the fuse per se, however with all things DC never confuse voltage with power and don't rely on a multimeter unless you are using it with a load applied, it is not unusual that a meter will show (say)12.8v but as soon as any load is applied this will reduce significantly or drop to zero due to resistance, a fuse holder is often the culprit.

The gas tight one-piece exhaust tube and silencer will take care of the exhaust noise quite nicely, the air intake roar and whistle can be almost eliminated by the use of the air intake silencer mount, if you have the proper red pump is should be fairly quiet but if you mount it in the correct place i.e. close to the dip tube you will be installing in the fuel tank and use the quiet mount it should not be intrusive. I have the standing offer open of a PDF copy of the correct narrowboat Webasto factory install manual to anybody who wants one (Though it comes with the kit if you buy the right one for the job) this has all you could possibly need to know, it doesn't contain views or opinions, it tells you the correct way to install the system and discusses pressure vs header, mounts etc along with every aspect of the install from start to finish. Send me an email address by PM and you will be far better armed to complete the install to a high standard. Motorcycle exhaust bobins are a decent way to mount the unit.

A pressure system would suit this system well, in fact pressure systems are almost all we do for new installs now. Correctly installed there is no opprtunity for leak back, just about every system in domestic systems is done this way now. I is very easy to introduce the 25% antifreeze solution before ptessurising the system through the top of the towel rad. Pressure is the way to go without a doubt in this instance.

If you would like a workshop manual drop me a PM with an email address. Though to be frank I wouldn' spend any real money on it unless it is under ten years old.

The correct fuel lines to BSS requirements comes in the kit along with everything else you need. You clearly have a vehicle kit looking at your earlier post so will have no warranty, the unit will cut out at higher voltages than proper unit. Why not just buy the right kit in the first place? Actually that question is rhetorical as I'm pretty sure I know the answer.

Install it property, use it properly and give it good clean fuel and it will serve well. The reason some are a pain in the arse is because they have been installed by people who think they know better than the factory instructions.

If you want to service it properly first invest in a flue gas analyser, pressure tester and software otherwise all you can do is a scrape out. I have seen more damage done to burner evaporators than I care to remember by people scraping at them.

No, you sound like you have a well balanced system and are using it in a way that should mean a long life for it. Even if you have to put a new burner in tomorrow you have had your money's worth.

Ignore the calorifier when working out the loading. Though it is a very good thermal dump when the potable water is cold it is soon at a point where it is taking less and less as the coolant and potable temperatures come closer together.

You are comparing hydronic heaters with air heaters that have more sophisticated controls with variable burn rates that do not cycle like water heaters, it's like comparing apples and oranges.

Calorifiers generally have a parallel thread, I normally use a JG Speedfit street elbow, compression nut and soft copper olive, you can then just connect the tube using normal method. Another way is to use a compression nut, soft copper olive and a short length of 15mm copper tube to make a spigot, the JG fitting will go straigh on to that. Edit to mention that it is worth remembering that 15mm compression fittings are threaded 1/2" BSPP, I just wish 22mm ones were 3/4" BSP.

It depends on the Boss, some are designed to use the O ring and have a tapered recess, some just have a flat surface for the gasket, so use the apropriate one, if it is designed for the gasket or O ring I use a little liquid PTFE more as a lubricant than a sealent to allow the gasket or O ring to spread, you shouldn't need anything on the threads of an Immersion, or any parallel threads, sealants are reserved for taper threads.

Not sure they will do retail but these guys make the best http://www.mehtatubes.com/copper-copper-alloy-fin-tube.html