Converting to hot water

chippysmith

chippysmith

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Joined
25 Mar 2006
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380
Location
Mid Bucks, Boat, Gosport
www.activedesign.org.uk
We have a beta recently installed on our Lotus 9.2. It has two 120 lt fresh water tanks, one for the galley and the other for the head. (no shower)

Galley tank is formed into bilge and head tank is within dinette seating, both tanks are showing signs of imminent failure. Will probably replace them with flexi-tanks, maybe re-sizing.

I'm thinking that now is the time to convert to hot water. I'm aware that I need calorifier, with PRV, would like a fixed mixer and immersion element. Would need new tap for the hot/cold water at both the galley and in the heads. I would also require electric pump and expansion vessel.

The boat is sailed by a crew of four, occasionally six. I would like a retractable shower head in the cockpit for the occasional douchè.

What escapes me is sizing the bits and pieces such as pump, boiler, exp. vessel etc

Does anyone have any experience with this sort of thing, would appreciate any help
 
I'd suggest you look for a 40 litre or 50 litre single coil calorifier, either vertical or horizontal, depending on how easily you can squeeze it in. Bear in mind it needs to be securely retained as it's very heavy when it's full.

As well as looking at the Cleghorn Waring offerings, you might also consider SureCal, who are also very helpful. The SureCal range comes complete with a thermostatic mixer valve and a pressure relief valve, and may be better value. I fitted one about 3 years ago, and was quite pleased by the apparent quality.

For best results, I'd go for about a 4 or 5 litre expansion tank. For the pump, look at something which will deliver at least 11 litres/min open flow. The Jabsco ParMax pumps are quite good (and some of them have an internal bypass which, they claim, means you don't need an expansion tank).
 
Thank you pvb, very helpful. Do you know of any pros/cons regarding tank material, I see both copper and stainless are available

Is the normal clear plastic hose used for cold water systems adequate for the hot circuit, I notice Hep2o for sale on the first website mentioned in this thread.

What type of plumbing/pipework is used connecting boiler to engine.

Thanks again for your input.
 
Copper is fine for the calorifier.

I'd use the 1/2" non-toxic red and blue hoses for distribution, rather than clear (one reason being that clear hose develops a green algae coating more easily). You could use Hep2O, but it's more expensive.

To connect the calorifier to the engine, use reinforced rubber hose (often called car heater hose).
 
Whatever you do, don't do what the late Mudplugger of this parish did - fail to specify whether he meant litres or gallons, and ended up with an enormously useless piece of copper.
 
We have a surecal 22l tank which works well for us general use and 2 good showers before it runs cold. Heated by electric in the marina to its max temp (80 deg) and then mixes to give a usable hot water temp.
 
There's an article in Sailing Today( the one that dropped into my letterbox yesterday) which looks at several models of calorifiers.
I haven't read it yet but it might be worth your while to invest.
 
I recently put hot water onto the boat, but decided not to plumb in the engine for various reasons, but mainly because I don't want to rely on it for the domestics,. Instead I will eventually put in an eberspacher water heater. I have a D5W set up in my garage as a trial.
I have two big (unknown capacity) tanks under the cabin floor. All piping is the reinforced plastic stuff, 10mm ID. Red for anything downstream of the calorifier, blue otherwise.The calorifier is a 22 litre horizontal Italian made jobbie with 1 Kw immersion and single coil, plus pressure relief valve.
The whole system is pressurised by a single 12v Sureflo pump. No expansion tank.
So far the system works well. The pump is only heard operating for a short time on switch-on and if a tap, hot or cold, is left on for a few minutes.
Outlets are: Galley - hot and cold pressurised. Cold - hand and foot pumped. Seawater - foot pumped. Heads - hot and cold pressurised.
When the Eber is installed it will heat the water through the calorifier coil and also provide heat for a heat exchanger, cabin heating for the use of.
Other than the Eber the most expensive part was the calorifier at £110 second hand off Ebay, then the pump at about £60.
 
Hot water on a boat is certainly well worth having. I find that after using the engine for half an hour there is enough to last through til the morning. Luxury. And free heat.
 
Do you need a calorifier just for washing hands? I have a nearly new gas rinnai water heater very cheap...needs brazing on two joints after the freeze.
 
Hot Water Surecal

Another vote for surcal based in Sandown Isle of Wight. Last summer they advised me and talked me through the installation I required. The size of the calorifer was simply the largest I could use in the space I had. This company actualy makes the equipment and supplied me at a price far lower than anybody else.
System works perfectly with 25 litre calorifier. They also advised me to install two expansion vessels which means no run off into the bilges as water heats up and also makes the pump run very smoothly.
 
Csail said:
Do you need a calorifier just for washing hands? I have a nearly new gas rinnai water heater very cheap...needs brazing on two joints after the freeze.
Click to expand...
I have just such a water heater, but surveyor not happy about it, nor is insurance co. Regretably will have to remove it this next winter for calorifer.
Why, Oh, Why do people keep on coming up with "non-compliant" when things work perfectly well? Licence to make things and add to that magic term "growth", I suppose.
If the compliant industry aren't careful, I'll give up the boat and then they will have no "growth" from me (and thousands others, I expect). Wasn't it the "goose that laid the golden egg" or something like that?
 
chippysmith said:
Thanks for that, yes good site but no information regarding what size calorifier, yes physical sizes are there but was looking for recommended volumes best suited to our needs.
Click to expand...

Get one that fits in the available space! You are in luck, there is a buyers guide in the latest Sailing Today, Page 34. Normally such articles get printed a month after I've bought something! :o


Just remember that you will need about 10 times as much hot water if you ever have women on board.
 
Last edited:
pvb said:
I'd suggest you look for a 40 litre or 50 litre single coil calorifier, either vertical or horizontal, depending on how easily you can squeeze it in. Bear in mind it needs to be securely retained as it's very heavy when it's full.

As well as looking at the Cleghorn Waring offerings, you might also consider SureCal, who are also very helpful. The SureCal range comes complete with a thermostatic mixer valve and a pressure relief valve, and may be better value. I fitted one about 3 years ago, and was quite pleased by the apparent quality.

For best results, I'd go for about a 4 or 5 litre expansion tank. For the pump, look at something which will deliver at least 11 litres/min open flow. The Jabsco ParMax pumps are quite good (and some of them have an internal bypass which, they claim, means you don't need an expansion tank).
Click to expand...

+1 for Surecal, but with a question you have to ask them before you order....

Last year we fitted a 55 litre Surecal calorifier with twin coils and 1KW immersion heater
5 litre expansion tank
Johnson 5GPM pump AT 42psi operating pressure

Last year the standard pressure relief valve that Surecal fitted was 3BAR, too close to pump pressure and with a tendency to blow off as water heated up. I complained to Matt Battle, the guy I was dealing with (and very helpful too) who advised me to fit a smaller pump. I explained that the smaller 30PSI pumps would not deliver water to more than one outlet without leading to a scalding risk in the shower. They did eventually relent and supplied me with a 4BAR PRV, but only after insisting that I post the old one back first! Still, all in all, happy with Surecal.

Make a point of telling them the pump pressure you are using so that you'll not end up spending 3 days waiting for the PRV!

To be fair Matt did email me to say that they were changing the website to cover the PRV problem but I've not looked.

The only other thing to mention is that the insulation on the Surecal is prone to blistering, and I mean BIG blisters. That was very worrying until I rang Matt and he said that this is normal and that it will settle down, which it did. No problems since.

Don't let any of the above put you off. The product is a very good price and the general quality very good.

As for the expansion tank, 5 litres is a very good size and does help the pump. We're fitting another one on the cold side to replace the 0.7 litre one we have now which is absolutely useless.

Hope that this helps. Stu :)
 
I have a calorifier that is not very satisfactory - not a generic fault of calorifiers, a specific problem with the original installation; basically a vertical cylinder was installed horizontally! Anyway, I am considering ways and means of correcting the problem; unfortunately, remounting the existing calorifier the right way up doesn't look feasible, at least, not without losing a lot of locker space - which is why, no doubt, the original "good enough" installation was carried out (back in 1989!).

I am torn between fitting a replacement horizontal calorifier and looking at a diesel powered water heater. I've got an Eberspacher hot air system that works fine, so I don't have any problems with the general idea of a diesel powered system, but the cost is off-putting - 3 or 4 times the price of a replacement calorifier. But the advantage is more or less "instant" hot water; the drawback of the calorifier is that if you haven't run the engine, you don't have hot water. I don't have a mains hook up on board, and don't want one, so a calorifier with an immersion heater is not useful.

Any suggestions?
 
stuhaynes said:
Last year the standard pressure relief valve that Surecal fitted was 3BAR, too close to pump pressure and with a tendency to blow off as water heated up. I complained to Matt Battle, the guy I was dealing with (and very helpful too) who advised me to fit a smaller pump. I explained that the smaller 30PSI pumps would not deliver water to more than one outlet without leading to a scalding risk in the shower. They did eventually relent and supplied me with a 4BAR PRV, but only after insisting that I post the old one back first! Still, all in all, happy with Surecal.
Click to expand...

That's a good point. It's not generally appreciated, but some pressure pumps are available in different pressure options. The Jabsco ParMax 11 litre/minute pump, for instance, is available with 1.7bar max (part 31395-0292) or with 2.7bar max (31395-0392). Worth checking before buying.
 
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