Calorifier Advice please - I thought this would be a simple project!!!

[Bilge Rat]

Why is everything on a boat so complicated?

After spending a delightful week at anchor in the Scilly Isles last year we maintained our batteries and hence our fridge by running the small generator for an hour each day,......... Now the small generator (1kW) provides more than enough for that task so I got to thinking that we could modify the immersion heater element arrangement to include 2 elements, one with a smaller output say 650 W for use with the generator at anchor and a standard size element for use on shore power. Hot water at anchor sounded perfect and as we plan to spend several months aboard this year in Scotland the real "must have" modification

My dear husband now has the cockpit locker emptied and is cursing like a trooper about the fact that the domestic immersion spanner won't fit, his grips won't budge it despite a night soaking with PlusGas and that under closer inspection he is now worried about the general state of the calorifier......... I thought this was going to be such a simple project! So the advice required is as follows:-
How long do calorifiers last? We believe ours to be the original fitted to our 1978 boat.
How do you budge the immersion element without damaging the calorifier itself?
Would my bright idea of 2 elements at different output levels work? Has anyone successfully done this?

 

[nimbusgb]

My calorifier disintegrated around age 22. It literally fell apart.

At age 30+ the chances of loosening that element without collateral damage are pretty slim.

not heard of anyone doing it but it appears to be a reasonable idea however I suspect it may just be simpler to downsize the element to one that the gennie can handle then shore power can run it as well, just takes longer to heat up than it used to.

No fiddling with a dual element installation or separate wiring or or or.

 

[Colvic Watson]

Surecal supplied a new 20 litre calorifier with a 750w element that the 1000w genny can easily handle, cost about £250 all in.

 

[vyv_cox]

At less than 20 years it was impossible to undo the blank in the top of my calorifier to replace it with an element. After replacing the calorifier I tried to remove the blank using severe measures but it was still impossible.

Have you checked the output of the existing element? Many fitted to yachts are fairly small, 650 - 850 watts, to allow for the low current available at many ports and marinas.

 

[Bilge Rat]

Thanks for the advice..... It is good to know that we could have a 750W element that the generator would support.... and we may yet be in the market for a new unit so thanks for the Surecal suggestion. I also think to keep the complexity down we will go with the other suggestion of just one element at the lower rating, providing that it will cope with our 40 ltr calorifier

We have only had the boat 2 years and whilst there is no paperwork on the age or spec' of the calorifier or element we do know that it trips the generator so it's obviously bigger than 1kW. The idea was to remove it today and check and then be able to spec' up something suitable to replace it.


Any other suggestions or thoughts would be greatly appreciated.

 

[SAWDOC]

I bought a boat last Spring with a burst calorifier. I found it very straightforward to remove (all pushfit fittings) and replace with a new identical model. So if you wish to avoid complexity, I would advise replacing like with like.
As noted above, the immersion on the original was immovable (30 year old boat).
I sourced my 20 litre vertical calorifier from Cleghorn Waring. Incidentally our calorifier uses heat from the engine cooling circuit rather than directly generated heat. We have the option of adding an immersion later (assuming blank ends are still removable!)

http://pressuresystems.cleghornwari...v3-20-litre-vertical-water-storage-heater.htm

 

[clyst]

I had the same problem with a 30year old unit . In despiration I used a chisel on the "flats" and a"gentle" sharp tap with a hammer released it . I'm not saying it will sort your problem but as a last resort ??

 

[Blueboatman]

I went exactly the same route as TheLazyKipper two years ago. Money well spent. Copper.
IIRC got £16 for the old Cleghorne Waring one, insulation and all, from the scrappy.

 

[laika]

I had the same problem: immersion had failed when I bought my boat 2 years ago and despite damage to the insulation and parts of my hands I failed to budge it with a variety of heavy duty borrowed tools. Replacing the calorifier has therefore spent a long time on the "to do" list but I've always been a bit concerned with any possible ill effects from airlocks which may result after re-pluming. Are my concerns imaginary and any air will be pumped round and out of the system?

 

[Sandyman]

Drain water. Remove all insulation around flange & stick a blow-torch on it moving round the flange to apply even heat. Get it nice & hot. Get a chisel/drift and wack it lose with an ammer.

 

[Pagetslady]

Drain water. Remove all insulation around flange & stick a blow-torch on it moving round the flange to apply even heat. Get it nice & hot. Get a chisel/drift and wack it lose with an ammer.

Leave water in almost to the the top and I used a vice upside down good purchase on the flats on the nut and a sharp tap it came free original fitted in 1987 I needed mine out to solder a leak in the tank where the Nut was braised in. But leaving water in supports the tank and a sharp tap in the right direction shifted it.
Mike

 

[Bodach na mara]

NB "tap" not "whack". Remember,
"Little knocks move mighty rocks
while bigger blows will break them."