Installing hot water

I’ve been relatively lucky the last few years, or perhaps ’successful’ is a better word, at persuading The Admiral that hot water on the boat is just ‘never gonna happen’. Several reasons:

• It takes a tremendous amount of energy to get it warm/hot.
• You end up wasting a lot of water before you get to the hot stuff, the pipes are invariable very long. And you can’t really insulate the hoses, it’s just a huge amount of effort for very little gain
• You need to alter a cooling circuit on an engine, which in many cases involves cutting pipes and can be a one-way affair. So a lot of stuff to undo if you get it wrong
• The mixer taps cost a fortune, have you seen the prices for marine ones??? 80 quid and up!
• Hot water is for wimps
• As soon as you put hot water in, you have to put a shower in, you have no choice
• Shower is definitely for wimps
• And so on

However, the more we thought about setting out on a long voyage, particularly the one that does not involve frequent marina stays, the more the idea appealed. Not to me, obviously, as I am clearly not a wimp, but there we are, I reluctantly agreed.

I figured that it’s probably a good idea to do the whole lot at once, i.e. bite the bullet and factor in the shower. In addition to this, the water tank is pretty small on Tingara, we only take on about 200 litres, so at the very least I figured we’ll increase the water capacity by 50 litres or so. Regardless whether we can heat it or not, it’s still potable.

So, a few stages then:

1. Shower tray
2. Calorifier
3. Hoses
4. Engine coolant re-route to flow via the calorifier
5. Other bits and pieces, such as extractor fan and taps

Stage 1 - Shower tray

1. This is probably the most complicated and time consuming part of the project. Basically, it consisted of:
2. Figure out where the shower is going to go, i.e. which floor panel in the heads will be removed and tray fitted
3. Make a male 3-D mould, out of cardboard. Make sure it fits the space under the floor panel
4. Sheath the male mould using resin and basic strand sheathing. Remove the mould
5. Keep sheathing and applying resin so as to make the sides smooth and waterproof
6. Sand down, apply a few more coats of resin
7. Fit a wooden plate that will hose the pump to pump the water out. Not a good idea to screw the pump into the tray itself
8. Run the hose out of the tray
9. Fit the tray
10. Seal around the edges
11. Make a GRP floor panel to replace the wooden panel
12. Drill a few holes in it so the water can drain
13. Fit the floor

Stage 2 - Calorifier

The most complex bit here is to decide what calorifier to buy. I went for the SureCal one. Seems to be well priced and so far works really well. I went for twin coils, just in case we fit a stove later on that just might have a slow pump to heat the water (1st coil is for the engine coolant). The original idea was to fit it into the space under the cockpit floor, but then I realised that I’ll never be able to get to the engine, so that was that.  Tingara doesn’t really have masses of space for a large calorifier. So I decided to put it high up in the quarter berth. This has several advantages:

• It keeps the space dry, as it’s always damp in there, due to very limited air circulation
• It still allows someone to bunk there, with the calorifier above their legs. Just about, but it will do, just.
• It’s close to the engine

There is one MASSIVE disadvantage

• The calorifier ends up being higher than the engine’s header tank. But this can be solved, see below.

The obvious disadvantage is that you lose the space, but then you are giving that space to drinking water, so that’s cool.

Stage 3 - Hoses

• These are pretty easy to run
• Hoses from calorifier to taps
• Hoses from water tank to calorifier
• Hoses from/to calorifier heating circuit from/to the engine

All are pretty easy, ignoring the normal bulkhead drilling and swearing, apart from the engine cut-in points. And, remember that for the engine coolant you’ll need to run high pressure hose, as it might just rip your normal hose to shreds when that engine water pump gets going at high revs. Any automotive stuff is good and pretty cheap. The rest of the hoses, in the low pressure areas, are just the normal hot water hose.

Stage 4 - Engine coolant re-route

What I went for in the end is a permanent addition to the circuit. So I pick it up off the engine block, before it goes into the exhaust manifold, and return it to the same point, just before the exhaust manifold, after it passed through the calorifier. When I have time I will get some valves and upgrade the permanent set up to a routable one, so that I can shut off the calorifier part of the circuit.

Stage 5 - Other bits and pieces

Taps I went for were the Plastimo ones. For some reason nobody stocks them, so it will take a few weeks to arrive, so plan for this

I put in a powerful extractor fan (bilge blower) in the heads. This has several advantages, it gets the moist air out and it makes a loud continuous noise, so that if you have an urge ‘to go’ you can do so in relative non-shyness

Photos of the process, they are pretty self explanatory

Tags: DIY, Hot water, Shower