Gibbo

Right, so it's actually only the AC that doesn't work? I'm assuming by "AC" that you mean air conditionning? Or do you mean an AC inverter?

Neither

Which electronics? I'm not trying to be obtuse, but there really isn't enough information. Then the AC unit is either installed incorrectly or not fit for purpose. I suspect the former.

So a narrowboat is a luxury item? Your post says it's not.

I've now read that 6 times and still can't work it out. Have you put a wrong word in or something?

We need clarification on exactly what that means before you can get any useful info.

But is it worth spoiling the sound?

This is probably a smart way of phrasing it. Nothing magical happens, earth has nothing to do with it. Just look at where the welding current might go if it's not exactly where you thought it might be when you first strike the arc up. Problem is, if that involves some electronics, it will be killed as soon as the first arc is struck (if there is a potential problem). The sensible thing to do is simple:- 1. Work out every possible return current (could take you weeks in a horrible welding position) and isolate them. 2. Isolate the entire elecrical system from the hull. There is no inbetween. Isolating the alternator or battery is akin to getting a voodoo doll out and hoping for the best.

Here is a rarity: I agree with a Carl My mate has a Taylors. He's beaten the living daylights out of it using it to heat his orangery (separate from the house) for a few years now and it continues to work like a dream. No problems, no maintenance issues, cheap spares etc. Just works perfectly every time it's needed... which is actually about 5 months per year continuously.

My Gardner has no air filter. It's not supposed to have one. It's still working fine 70 years later.

"Spinny" uses much more power than "pulse" (we know what you mean) for the same pressure. It doesn't really matter in a house but it's big issue on boats. I think that's likely to make it worse. A smaller one might not start it up properly.

I agree with this, but what use is one if it idoesn't throw out enough heat to keep your boat warm? From what's been ascertained, it either has less output than claimed, or it uses more fuel than claimed. Or perhaps a bit of both.

The website claims:- Will run for 4.5 hours on 1 litre of diesel at full power. Full power is 3.5kW That is a physcial impossibility. Assuming a completely perfect heater, that turns all the diesel into waste by-products and that leaks absolutely no heat out of the flue, the theoretical maximum for 1 litre every 4.5 hours would be 2.3kW. A typical diesel heater is about 60% efficient so that would reduce to 1.3kW. ETA. My figures roughly agree with Ditchcrawler's. Someone is telling porkies.

Believe it or not, they're actually electrically completely isolated. Not that it would make much difference as Gardners are full of all sorts of different metals: bronze pump, brass flanges, copper pipes, alloy crank case, steel cylinders. I figured I wasn't actually making things much worse!

I can't help it if I didn't see the thread. Obviously not many people did because the people who do know what they're talking about didn't reply to it. Just your incoherent blathering.

This is what makes me think it's a measurement issue in the Victron. You change the setting to weak AC, it pulls more current, the generator voltage collapses, the actual charge current drops. None of it makes any sense except for a distorted waveform which fools the Victron measurements.

Precisely. Some people seem to think something magical and mysterious happens when an arc welder is taken near a boat. The same people also seem to think that disconnecting the batteries or the alternator somehow makes something even more magical and mysterious happen which prevents any damage. Problems can crop up in some instances. Imagine welding an exhaust to the hull. The welder's first strike hits the exhaust instead of the hull. The welding current now goes through the exhaust, the engine block, the gearbox and may weld the prop shaft to the stern tube. Or perhaps it goes through the throttle linkage cable and destroys that. Or a gearbox. Similar thing could happen welding a steel overflow to a water tank. There are many scenarios where a problem could occur. These aren't electrical issues but everyone can see the possible problems and take steps to solve them. When it comes to electrical issues they think disconnecting the batteries will cure it. It won't. It's nothing more than an old wives' tale. Think of the exhaust on an Eberspacher or Mikuni. If the first strike hits the exhaust, the welding current will go through the negative power feed to the heater. Either the cable or the control box will go pop. Just blindly disconneting the batteries or the alternator will not make the slightest bit of difference to any of the above examples. Ok. I just won't tell you instead. Listen to one who knows nothing about the subject instead. Makes no difference to me. Edited to remove entirely justified insult.

Spam alert. Which will achieve nothing. It's been covered a thousand times on here.

The new one builds its own battery model automatically. I'm going to have that as model number 42. Don't fret. It's still some way off as I keep getting put on other projects.

The four posters who told you that was probably the problem?

Presumeably the same place as the energy used to later purify the hydrogen. Someone is having a giraffe.

Now there's a possible easter egg for the new one...

You're missing the point of what I'm saying. You said... By setting weak AC, somehow, the efficiency has absolutely plummeted to some horrible figure. It's hard to say without the actual voltage reading so let's assume they're the same in both cases. Your first figures give an efficiency of 85% The second figures give an efficiency of 44% I'm not having it! It would melt itself. I think it can't measure the current properly unless it's a true sinewave input. And I further think that setting it to weak AC input is causing it to try to draw more current which is distorting the generator waveform. In which case all the figures it gives are bollocks. But it makes more sense than the charger suddenly becoming a 750 watt heater when you change a setting.

Yes.

85% to 90% would be about right. It's not just a lot. It's just plain wrong.