adding a hot water system to a cold water only sailboat

Marceline

Marceline

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Hello - this is another 'new to sailing' type question so apologies if making blundering errors/assumptions etc

We've enjoyed our first year of sailing in our little Jaguar 24 but it's quite cramped inside for two/only really able to day sail/weekend etc and we'd love to move up to bigger 30'+ boat for longer journeys. We've been looking at various types but one that's stood out and ticked a lot of boxes for us sadly dosen't have hot water (or shower) and we just wanted to ask about how much of a headache/doable is adding a hot water system for a sailboat.

The heads is right next to the diesel engine so I guess a calorifier could be an option. Theres a lot of solar and batteries for the boat so having an emersion could work as well. The boat also has a lot of water tanks on board so there's a lot of fresh water we can use. I 'think' the engine is cooled by seawater intake (I'll double check that)

The boat also has a lot of gas onboard so also wondering if a gas/propane water heater could also be an option (we've viewed a couple of boats so far that had those) ?

Know this is also adding complexity as well, but a couple of radiators in the boat would also be great if possible (we're hoping to sail to more northerly places) and again we'd seen a boat that had those (a marvellous Colvic Victor ketch but sadly that has now sold)

So, just wanted to ask, if you were looking at an older boat with no hot water how would/have you approach things ?
 
Last edited:
Marceline said:
Hello - this is another 'new to sailing' type question so apologies if making blundering errors/assumptions etc

We've enjoyed our first year of sailing in our little Jaguar 24 but it's quite cramped inside for two/only really able to day sail/weekend etc and we'd love to move up to bigger boat for longer journeys. We've been looking at various types but one that's stood out and ticked a lot of boxes for us sadly dosen't have hot water (or shower) and we just wanted to ask about how much of a headache/doable is adding a hot water system for a sailboat.

The heads is right next to the diesel engine so I guess a calorifier could be an option. Theres a lot of solar and batteries for the boat so having an emersion could work as well. The boat also has a lot of water tanks on board so there's a lot of fresh water we can use. I 'think' the engine is cooled by seawater intake (I'll double check that)

The boat also has a lot of gas onboard so also wondering if a gas/propane water heater could also be an option (we've viewed a couple of boats so far that had those) ?

Know this is also adding complexity as well, but a couple of radiators in the boat would also be great if possible (we're hoping to sail to more northerly places) and again we'd seen a boat that had those (a marvellous Colvic Victor ketch but sadly that has now sold)

So, just wanted to ask, if you were looking at an older boat with no hot water how would/have you approach things ?
Click to expand...
I added a hot water system , very pleased with it, the pumps, accumulators and tank take up a fair bit of room which I would guess on a 24 ft boat might be a problem, water is heated by the raw water cooled engine or 240v .
 
Thanks Europe - thats good to know

I guess I should emphasise that the new boat were looking at is much bigger than 24' (that's our current boats size and we're not looking to add hot water for that)
 
Two main ways

Hot water tank heated by engine and /or electric emersion heater.

OR

An instant water heater using LGG of mains electric

I have both on my current boat
 
Thanks Johnalison - I guess we'd be using it a fair amount to wash hands / quick body wash and have short showers every few days. The tanks on the boat we're looking at add up to 350L
 
Thanks Wingcommander and I'll look into those.

Not sure if that would work with type of heater this boat has (not sure of the make) is the kind of drips diesal onto a hot plate (again, I'll double check this with the broker) - but I'll look into the Bobil range and try and undestand more
 
Another way is fitting a diesel water heater - the best known are Webasto Thermo Top C, Eberspacher Hydronic or Autoterm Hydronic range. Melloronline website is a good source for typical installation diagrams.* For hot water I think most often the coolant from the heater is piped to a calorfier but it can also be piped to a plate heat exchanger for instant(ish) hot water.
As mentioned earlier all the equipment can take up fair bit of space and can be difficult to do a neat installation.
* Technical Support for Night Heater Kits, Eberspacher, Webasto, Mikuni, Durite Click on Download Centre
 
Marceline said:
oh wow - so is that some kind of heat exchange from the outake of the seawater cooling before it goes out of the hull ?
Click to expand...
With a freshwater cooled engine, it would be a heat exchanger in the freshwater cooling circuit, as this is a lot hotter than the seawater. With a raw water cooled engine, it could still be done, there's bound to be a pipe you could divert to a heat exchanger, but you wouldn't get the water as hot, because a raw water cooled engine has to run cooler to prevent excessive limescale buildup.

You aren't going to get enough power out of solar panels to heat water, especially not if you want a radiator or two. Realistic options are a heat exchanger from the engine, mains power in a marina, or a diesel heater.

The Geyser type of heater mentioned by Poignard has been pretty much regulated out of existence now because burning quite a lot of gas in an enclosed space risks CO poisoning.
 
Nothing difficult about it at all on the sort of boat you are looking at (if the Colvic Victor size/type is where you are looking). While there are alternatives, a calorifier taking waste energy from the engine and feeding a pressurised water system is pretty much universal. The only real challenge is finding space for the calorifier and running the new pipework to the galley and loo. This will give you an idea of the hardware required
asap-supplies.com/domestic-water-supply
and if you google "installing hot water in a yacht" you will get a whole raft of articles and youtubes covering all stages of installation.

Likewise if you want to install heating the most common is blown hot air using a diesel fired heater. Common brands are Eberspacher, Webasto, Mikuni plus similar types from China.
 
Don't know about the UK but we have room sealed hot water heater mainly LPG.

This is how mine works so no combusstio products inside he cabin so no risk of CO.

As the combustion only takes place when the water is running and being heated very little of chance of CO being produced at night when asleep
 
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