Calorifier immersion heater

[Porthandbuoy]

I’m thinking of adding a 240V immersion heater to Sheolin’s calorifier tank as the hot water doesn’t last long when we’re in a marina. There’s a blanking plug fitted so getting one to fit shouldn’t be a problem. The question is, what wattage should I go for?

 

[RupertW]

I’m thinking of adding a 240V immersion heater to Sheolin’s calorifier tank as the hot water doesn’t last long when we’re in a marina. There’s a blanking plug fitted so getting one to fit shouldn’t be a problem. The question is, what wattage should I go for?

How big is the tank? 1500W is usually a good size but if it’s a smallish tank and just you needing a shower then lower wattage is fine.

 

[fredrussell]

I’m no sparky but I reckon you need to do a 240v energy audit, work out what the max current draw is with all boat appliances on the go and see what you ‘have left’ from your shore power supply. Then go for the largest heating element you can safely add without overloading the supply.

In the interests of full disclosure I should state that the last person that took advice from me on boat electrical systems ended up with a smouldering pile of fibreglass and molten aluminium.

 

[Porthandbuoy]

I’m no sparky but I reckon you need to do a 240v energy audit, work out what the max current draw is with all boat appliances on the go and see what you ‘have left’ from your shore power supply. Then go for the largest heating element you can safely add without overloading the supply.

In the interests of full disclosure I should state that the last person that took advice from me on boat electrical systems ended up with a smouldering pile of fibreglass and molten aluminium.

Good point. A240V audit is easy; one battery charger and a rarely used small 700W oil filled radiator.
The limiting factor might be the shore supply. I’ll phone my local marinas and find out what the score is.

 

[vyv_cox]

The immersion heater in my EU bought calorifier is 850 watts. It will run on EU marina supplies that are often limited to 6 amps. A calorifier fitted to a boat I know has a far bigger immersion heater that trips many supplies. Running it via a voltage reducer at 100 volts seems to solve the problem.

 

[oldgit]

Be ready for the fact that element for the tank although physically smaller in order to fit into the tank and also of a lower wattage , will cost about £40 from ebay or up to £90.00 from a chandler.
Most seem to be from 600W to 800W.
Did add a cheapo small domestic insulation blanket to my tank, made a noticable difference to tank warm up time and and how long water stayed warm once heated.
We have 16A on our moorings, you can run 800W immersion plus a 2K electric fan heater , it sometimes objects to the addition of a kettle.

 

[PCUK]

Stick to 1000w or less and definitely use a double insulated element otherwise it is likely to constantly trip the marine breakers.

 

[Irish Rover]

My 22L SureCal has a 1Kw element. Maybe check the Surejust website and see what they're fitting to your capacity calorifer.

 

[RupertW]

Stick to 1000w or less and definitely use a double insulated element otherwise it is likely to constantly trip the marine breakers.

Where are all these marina with 4 or 5 amp breakers. I haven’t less than 16 amps in EU for 15 years and longer in the Uk.. Is this Northern France?

 

[PaulRainbow]

Where are all these marina with 4 or 5 amp breakers. I haven’t less than 16 amps in EU for 15 years and longer in the Uk.. Is this Northern France?

Did some work in a boatyard a couple of years ago, in Essex, that had a 6a supply, other than that, all have been 16a minimum.

The main issue with higher wattage elements is tripping due to using other appliances. My current boat has a 3kw element and we were on on a 16a supply, if we turned almost any other 240v equipment on, the shore side trip popped if the immersion heater happened to be on. Never knowing if it was on or not, we had a lot of random trips. I did consider changing the element for a 1kw version, but since fitting a timer, set to come on for an hour in the morning, before we get up, it all works fine.

 

[vyv_cox]

Where are all these marina with 4 or 5 amp breakers. I haven’t less than 16 amps in EU for 15 years and longer in the Uk.. Is this Northern France?

Netherlands, Belgium, Atlantic and Mediterranean France, Spain, Italy, Greece. All marinas I have used. Nearest to UK I know is one of the two at Dunkerque.

 

[RupertW]

Netherlands, Belgium, Atlantic and Mediterranean France, Spain, Italy, Greece. All marinas I have used. Nearest to UK I know is one of the two at Dunkerque.

That is extraordinary, I have had 16amp (and usually 32 but I dont need that) in Spain, Italy snd Croatia without any issues. And also in UK South Coast up to the point I sold my boat in 2018 there and always ran at least 1 fan heater in any marina except in mid-Summer.

 

[vyv_cox]

That is extraordinary, I have had 16amp (and usually 32 but I dont need that) in Spain, Italy snd Croatia without any issues. And also in UK South Coast up to the point I sold my boat in 2018 there and always ran at least 1 fan heater in any marina except in mid-Summer.

Of course, I have had the same but there are still plenty of places using domestic two-pin sockets. My boat has not been in UK, other than brief visits, since 1997, so I cannot comment on that.

 

[vyv_cox]

That is extraordinary, I have had 16amp (and usually 32 but I dont need that) in Spain, Italy snd Croatia without any issues. And also in UK South Coast up to the point I sold my boat in 2018 there and always ran at least 1 fan heater in any marina except in mid-Summer.

The one I referred to above, where a voltage reduction to 100 volts solved the problem, was last week in Rochefort.

 

[Plum]

I’m thinking of adding a 240V immersion heater to Sheolin’s calorifier tank as the hot water doesn’t last long when we’re in a marina. There’s a blanking plug fitted so getting one to fit shouldn’t be a problem. The question is, what wattage should I go for?

Mine has a 1.5KW heater element and I have never had a problem in UK waters or near continent. It is 24 years old. Adding 50mm of additional good insulation around the calorifer makes a big difference to how long the water keeps hot.

 

[KompetentKrew]

Where are all these marina with 4 or 5 amp breakers. I haven’t less than 16 amps in EU for 15 years and longer in the Uk.. Is this Northern France?

I have 8A at my current boatyard in Portugal.

The "inverter assist" functionality of my Victron Multiplus is proving to be a godsend, as it allows me to plug in high-draw devices for short periods. This necessitates juggling what's plugged in, but smart sockets help.

I currently have a 1.5KW element in mine, but would choose a 750W or 1000W if I had to replace it - to say which for sure I'd have to ponder longer, but 1.5KW is just enough that, with my current supply, I can't run anything else when the immersion is on. 16A would be a dream - I feel right now like it's something I always took for granted.

 

[oldgit]

From shore to end of furthest mooring on our pontoons is about 1/4 of a mile.
It takes the wife 20 mins to walk from boat to bar.
She has timed it to the second.

Frequently wondered how many volts get to the far end.
Seniority in the club and sucking up to the mooring master gives one serious advantage, we now moor much closer to the clubhouse.