Quick Water Heater Issue

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TQ1

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Hi

New to the forum. Could do with a bit of advice. We kept tripping the fuse on the shorepower unit on the marina. We've plugged it into another socket on the marina and this tripped as well.

After some testing narrowed it down to the Quick water heater (B3 25 litre). Strange thing is that it doesn't happen all the time or follow any pattern say when it has been on for an hour.

The boat is only three years old.

Any thoughts?

Thanks

Simon
 
When you say 'fuse', do you mean the MCB (circuit breaker) on the mains outlet box on the pontoon? This will trip out if there is more than 30mA stray current being dumped from live to earth. I would worry about, and find out why, the MCB on your boat switch panel doesn't trip out first!

I don't think it matters exactly what brand of water heater it is. As it's summer already and boating time is precious: I would just change the element and thermostat (both are liable to crack open at high temperature thus providing a short circuit to earth) and get your switch panel checked.
 
Thanks Jerry. I spoke to the company who sold me the boat and they think the MCB on the pontoon may be more sensitive than the boat.

In any event I’ll get it all checked out / changed just to be on the safe side and not use it until then.

Regards
 
Hi

New to the forum. Could do with a bit of advice. We kept tripping the fuse on the shorepower unit on the marina. We've plugged it into another socket on the marina and this tripped as well.

After some testing narrowed it down to the Quick water heater (B3 25 litre). Strange thing is that it doesn't happen all the time or follow any pattern say when it has been on for an hour.

The boat is only three years old.

Any thoughts?

Thanks

Simon

Keep an eye on it, it’s the first sign of the element fizzing away to nothing. Starts with irregular tripping and ends in a bang...
I’d get the element checked when you are able - might need a special hub nut socket like this - Laser 4835 Hub Nut Socket, 54 mm https://www.amazon.co.uk/dp/B003AN3ONO?ref=yo_pop_ma_swf

But get the element checked imho...
 
Thanks Nigel. Just organised for it to be looked at and also check the boat electrics out. The marina guys did think the MCB’s on the marina are more sensitive than the boats but will get it checked professionally anyway.
 
hi had same problem last year was the element breaking down with a small water leak in the plastic cover causing the electric to trip , replaced the element problem solved, the dearest part was the socket to remove it.
 
Thanks Nigel. Just organised for it to be looked at and also check the boat electrics out. The marina guys did think the MCB’s on the marina are more sensitive than the boats but will get it checked professionally anyway.

Good stuff, try to be on board when they come and watch how to isolate the water supply, drain and remove the element. Then order a spare element regardless - you’ll save yourself some pain further down the line...
Good luck
 
Many marines fit B curve MCBs whereas boats really need slower C Curve.

If you look closely at the breaker it will be marked something like B16 or C16, where the B is the trip rated trip curve and 16 is the amps rating.

A quick heater will likely have a 3kw immersion so that in its own would be 12 of those 16 amps, so a battery charger and a kettle perhaps and you've used your 16 amps.
 
Well, I don't have an emergency replacement element for my calorifier on board, does anyone? Spend the money on spare bilge pumps and float switches, you will need them.
 
Many marines fit B curve MCBs whereas boats really need slower C Curve.

If you look closely at the breaker it will be marked something like B16 or C16, where the B is the trip rated trip curve and 16 is the amps rating.

A quick heater will likely have a 3kw immersion so that in its own would be 12 of those 16 amps, so a battery charger and a kettle perhaps and you've used your 16 amps.

What he said.
The B type are more ambient temperature sensitive (or the ones where we are, are). The other day 23 deg I kept tripping a 16a breaker at 9a (Superheat, that’s why I had unplugged yours, sorry forgot to tell you)

There could be an over load, turn everything off and just run the water heater to see if it trips
Also you say it trips after an hour, could imply that after an hour of heating the element expands and causes an earth leakage enough to trip
 
Well, I don't have an emergency replacement element for my calorifier on board, does anyone? Spend the money on spare bilge pumps and float switches, you will need them.

Well obviously I do ;)
But of course, We use our boat a lot and it’s not always easy to get spares in a hurry in some of the places we’ve visited and plan to visit so my spares list is, shall we say, comprehensive; from adjustable timer relays and fuses to macerators and pumps - it’s lucky that we have two hulls on our boat and plenty of storage :)

For the OP, being new to boating, getting a good handle on the hot water system is a good idea imho, it’s convenient to be able to fix these things without having to wait for or find a local artisan.

Oh and according to Ann’s spare part spread sheet we have 2 Rule auto bilge pumps ready for action should/when the existing ones fail, which they will...
 
Thanks Nigel. Understand both points of view but it's definitely worth understanding more about how the boat works rather than wading through the 300 manuals that it came with :o)
 
What he said.
The B type are more ambient temperature sensitive (or the ones where we are, are). The other day 23 deg I kept tripping a 16a breaker at 9a (Superheat, that’s why I had unplugged yours, sorry forgot to tell you)

There could be an over load, turn everything off and just run the water heater to see if it trips
Also you say it trips after an hour, could imply that after an hour of heating the element expands and causes an earth leakage enough to trip
I thought I had upset Anthony ! If I were on the marina 24/7 I would simply obtain the same make but is D Curve.

Also if they operate a few times the springs weaken so they trip off earlier. 8a on a 16a load is bit piss poor.

I was a bit surprised that the no1 socket I then plugged into tripped immediately, but doubt the yard will do anything about it.
 
I thought I had upset Anthony ! If I were on the marina 24/7 I would simply obtain the same make but is D Curve.

Also if they operate a few times the springs weaken so they trip off earlier. 8a on a 16a load is bit piss poor.

I was a bit surprised that the no1 socket I then plugged into tripped immediately, but doubt the yard will do anything about it.

The two I had connected to and tripped would not even reset with no plug connected, was only trying to boil my specially purchased 1700w kettle so it wouldn’t trip, it did
 
If you berth in Cala Dor you do... they last 6 months due to the salt water they pass off as tap water ....

Agreed - but not just Cala Dor

This all sounds like a bit of old TOSH from the company that sold you the boat.
In my experience, immersion heaters deteriorate over a period of time and cause electric leaks to ground.
Then RCDs will trip - that is what they are supposed to do.
In this case, I would replace the immersion heater and new ones usually come with a new themostat.
It has happened several time to us - just change the immersion heater and all will be well.
In fact, I find that the marine immersion heaters are more susceptible to failure than a standard domestic one.
Ours is 3Kw so it is easy to find a domestic replacement.
I think I bought 2 last time at about £11.00 each
The biggest problem we have is draining the water to fit it.
Finding the right size spanner/socket out here in Spain was difficult - the local domestic ones are much smaller.

TQ1 - would that be in Devon?
 
Hi Hurricane, yes, that would be in Devon!

It hasn't happened again so I think it could have been a case of having too many gadgets on as a number of people mentioned! The fridge would have been on as well.

I'll get it all checked out anyway just to be on the safe side.

Thanks

Simon
 
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