Calorifier Size.

[SiteSurfer]

SWMBO has agreed that we need a calorifier.
The boat is 29ft with a reasonable space aft in the engine compartment to fit said calorifier, we normally cruise with 4 people, have no shower or anything fancy like that. Mainly for washing up and the occasional splash over the face.

What sort of size calorifier would suit? I was thinking 20 litre but didn't know if that was too big? Anyone got any real world data?

 

[essexboy]

I don't see how it could be too big, you are heating the water for free, so you might as well get as big as will fit or as much as you want to pay. My water is still fairly warm the next morning. Weight may be a factor on a rag and stick thing !

 

[Quandary]

20l. is fairly commonplace, avoid ISO******** , shiny Italian stuff that leaks at its daft gaskets the first time you crash a big wave, I recommend Surecal, made in the IOW with copper and brass, not as pretty but proper quality British manufacture designed to last more than a year or two and cheaper.

 

[vyv_cox]

Ours is Italian, Sigmar Marine, and has fortunately been totally fit-and-forget for the past 12 years or so. 20 litres is certainly big enough for four people and doesn't occupy too much locker space.

 

[Plum]

SWMBO has agreed that we need a calorifier.
The boat is 29ft with a reasonable space aft in the engine compartment to fit said calorifier, we normally cruise with 4 people, have no shower or anything fancy like that. Mainly for washing up and the occasional splash over the face.

What sort of size calorifier would suit? I was thinking 20 litre but didn't know if that was too big? Anyone got any real world data?

Too big can be a problem as it will take a long while to heat up. Obviously depends on length of trips you usually do. It can also increase the time taken for your engines to reach full working temperature. I have a Volvo Penta thermostat that is specifically designed to be fitted in the engine to calorifier hose which restricts the flow until the engine coolant gets to a certain temperature so ensuring good engine warmup before the calorifier starts heating.

Www.solocoastalsailing.co.uk

 

[Tiller Girl]

Ours in 32ft of a wooden MAB is 22l which as large as we can fit. Bear in mind that the water is so hot that it is always blended in with the cold water so the capacity of hot water is probably double for washing up/washing. We have a thermastat valve fitted to the calorifier to blend hot and cold together. Enormously effective.

 

[Jabs]

Ours in 32ft of a wooden MAB is 22l which as large as we can fit. Bear in mind that the water is so hot that it is always blended in with the cold water so the capacity of hot water is probably double for washing up/washing. We have a thermastat valve fitted to the calorifier to blend hot and cold together. Enormously effective.

Plus One!

Keep it as hot as possible and as stated above, fit a valve to provide the temperature appropriate for use.

Obviously settings can vary. We keep delivery relatively warm but is we had little peeps on, maybe colder.

Tony.

 

[Hydrozoan]

It's not necessarily just a question of water volume. We have a 22l Surecal (copper) on a 32ft boat largely because it was the configuration (relatively short and fat) which fitted easily into the most convenient space - smaller volume (15l) ones were actually debarred by being longer and thinner!

IIRC the 240V immersion is 1kW and that takes about an hour to full heat, but the engine is much quicker (30min or less with 18HP engine) and 22l is fine for two of us (washing up/washing, but not showering; still warm next morning). I have no experience of other brands, but found the Surecal technical man very helpful.

 

[prv]

Having had a boat without it and then one with, running hot water makes a big difference to the level of civilisation on board. 95% of the time we have hot water available and just don't think about it, but occasionally we'll go two nights without running the engine (or mains power) and by the second evening we'll be back to boiling a kettle to wash up. When that happens it really feels very primitive

Pete

 

[GHA]

Having had a boat without it and then one with, running hot water makes a big difference to the level of civilisation on board. 95% of the time we have hot water available and just don't think about it, but occasionally we'll go two nights without running the engine (or mains power) and by the second evening we'll be back to boiling a kettle to wash up. When that happens it really feels very primitive

Pete

I've not had hot water for 10 years full-time onboard... might invest in replacing the bust calorifier after reading this thread...

Thnx!

 

[lw395]

Depends if you expect showers.
If the water is plenty hot, how much water do you need for a quick shower?
The kind of quick shower that is just enough to feel civilised going ashore after a hot day?
I think in winter you will need a lot more hot water for an acceptable shower, unless the boat is well heated.
I think our calorifier is only 30 litres, but 2 or 3 people can get a reasonable shower on a hot day while motoring. I suspect the water re-heats for the third person?
It is nothing like a power shower, water capacity is too low for that, we are very careful to be mean with the hot water.
There is a safety-mixer valve thingy in the head.

 

[SiteSurfer]

I did mention that we don't have a shower - quite possibly no way of getting one in either unless you could do contortions around the sea head
The engine is a Volvo MD2010 which i have been unsuccessful in getting any advice thus far on whether its able to support a claorifier without cooling the water flow too much. I think I'll actually walk around to the engineers this weekend and ask directly.

I am wishing to replace a perfectly serviceable gas water heater which I simply don't like, its vented directly to the heads compartment and needs a skylight open to work and I worry about the hot exhaust straight on to my grp liner.

The brand I looked at was surecal, they do one which is 15 litres and a perfect size, it sounds like the capacity is not so much of a worry.

 

[duncan99210]

That engine will happily heat a calorifier. The take off for the calorifier pipes is down stream of the thermostat, so it won't get any heat until the engine is up to temperature. Once it's at running temperature, the additional cooling effect of the calorifier coil won't have any significant effect on engine temperature.

 

[yoda]

I did mention that we don't have a shower - quite possibly no way of getting one in either unless you could do contortions around the sea head
The engine is a Volvo MD2010 which i have been unsuccessful in getting any advice thus far on whether its able to support a claorifier without cooling the water flow too much. I think I'll actually walk around to the engineers this weekend and ask directly.

I am wishing to replace a perfectly serviceable gas water heater which I simply don't like, its vented directly to the heads compartment and needs a skylight open to work and I worry about the hot exhaust straight on to my grp liner.

The brand I looked at was surecal, they do one which is 15 litres and a perfect size, it sounds like the capacity is not so much of a worry.

I have a 15l surecal and it does me just fine when only 1 or 2 onboard.

Yoda

 

[Tiller Girl]

I did mention that we don't have a shower - quite possibly no way of getting one in either unless you could do contortions around the sea head
The engine is a Volvo MD2010 which i have been unsuccessful in getting any advice thus far on whether its able to support a claorifier without cooling the water flow too much. I think I'll actually walk around to the engineers this weekend and ask directly.

I am wishing to replace a perfectly serviceable gas water heater which I simply don't like, its vented directly to the heads compartment and needs a skylight open to work and I worry about the hot exhaust straight on to my grp liner.

The brand I looked at was surecal, they do one which is 15 litres and a perfect size, it sounds like the capacity is not so much of a worry.

I fitted from a 2030 and have the VP instructions which are generic for 2010, 2020, 2030 and 2040. There is an image of each engine and the instructions comprise (totally):

The arrows on the connectors indicate the direction of flow of the water. The recommended hose dimension hose dimensionis 16x4mm. The hoses should be bent in gentle curves and in a way which avoids them being pinched or kinked.

When there is a large comsuption of hot water (long engine heating time) the system should be supplemented by a thermostat (hose thermostat 855844) at the outlet connector.

The upper edge of the hot water should be placed min.50mm below the engine's heat exchanger.

If expansion tank kit 861498 is mounted, the upper edge of hot water heater should not be placed higher than the 'Min' marking on the expansion tank."

That is the total of the instructions apart from the usual VP liability words. I'll add the image dans a few minutes.

 

[SiteSurfer]

Thank you so much! Thats not a huge job at all - I was thinking it was an engineer only job.

 

[prv]

I was thinking it was an engineer only job.

Few things are on yacht diesels

Pete

 

[SiteSurfer]

I have an odd relationship with engines, ones that run perfectly seize up within minutes of being owned by me, they develop oil leaks where once any sign of oil was never seen... you get the idea.
It all started when I once disassembled a Honda 125 engine and had to resort to taking damn thing to a local dealer in a bread basket after finally admitting defeat.

As a result I usually hear the word engine and start looking for someone to do it for me, however even I can do 2 bolts.

 

[Trundlebug]

I would only add (it's been alluded to above) there's no such thing as too much hot water!

If you fit one smaller than you could have, you'll curse when you need to boil the kettle just for a wash or shave on the second morning after being at anchor. Having hot water on tap makes it feel luxurious on board. It's what sets it apart from camping.
Don't worry about heating up time, the difference will be negligible between a smaller cal and a larger one, as the heated water rises to the top of the tank where it's drawn off anyway.

Within a few minutes you'll have piping hot water regardless of tank size; only the amount will increase with more time running.

I had the space so I fitted an extra calorifier in series with the original, more than doubling the capacity. We now have enough hot water for 4 showers, plus washing up and a wash the next morning, no problem.

I'm also never worried about the shower going cold on me half way through - it was worth all the effort and work of the installation just for that peace of mind as it's something I really hate!

 

[PotatoNavigator]

If it's only for warm washing up water and you don't anchor much, or if you spend a few days in a marina at a time without using the engine, what about an 240v inline instant hot water heater ≈ £100?

https://www.aquahot.co.uk/wijas-3500b-perfect-3-5kw