Fitting a hot & cold water system?

[Guest]

I have a 1979 Nicholson 31 that we have had from new. We have always had just cold water with hand pumps at each basin. The heads even has the place for a shower head but one has never been fitted. I think it was a very expensive option back then! What would be involved with having hot (pressurised?) water? Is it a mamouth task? Can anyone fit it or are there specialised firms who could help? Many thanks in advance.

 

[ccscott49]

Its not a mamouth task, but the makers of your boat would probably be the best people to ask, reference where they installed the calirifier and pump etc. Without looking at your boat I wouldnt be able to help, but I'm sure other owners will be able to help. You will wonder how you managed without hot water once you have it, very pleasant!

 

[scottie]

Have a look at cleghorn waring site it is

http://www.cleghorn.co.uk/help/pwshlp/layout.html

this will have the technical answers
but you don’t say what engine you have as if it is salt water cooled it will take a long time to get enough heat into the system as you normally run salt water at 60c fresh will be about 75c

 

[vyv_cox]

A properly designed raw-water cooled engine domestic heating system will heat an appropriately sized calorifier in very little longer than a fresh water cooled one. I recently replaced a raw water cooled Bukh with a fresh-water cooled Yanmar. Calorifier heating rate is very little different, in either case the water is up to hot to the touch in about 20 minutes of motoring. The main difference is that the equilibrium temperature with fresh water is higher, sometimes almost dangerously so.

Fitting a hot water addition to an existing pressurised system should be very easy. Branch the supply downstream of the pump, taking this to the heater/calorifier. Output of the heater goes to the new hot tap.

 

[charles_reed]

Calorifiers and Bukh engines

I believe we've discussed this before, Vyv - the ONLY raw water cooled engines to which you can fit a calorifier are Bukh engines, which have a special take-off at the top of the head.

Otherwise you need indirect cooling.

You could (illegally without an external flue) fit a gas geyser such as the Paloma (available from caravan shops at 65% of the price in chandlers).
The cleghorn waring range is probably the best - BUT think on.

The reason your boat was fitted with only hand-pump system was because a previous owner thought his water capacity too small to risk cavalier usage by careless crew.

Allow 2.5 galls per crew/day with electrics and 1.0 with hand pump only.
To avoid being scalded by the calorifier requires a thermostatically operated bypass on the heating input - the plumbing this entails tends to be beyond most boatbuilders.
You also need to fit an extra large pressure reservoir to allow for the expansion/contraction of the water in the calorifier.
In answer to your question - yes it is a major project, especially as you'd be well advised to replace all your current piping with rigid pvc to withstand the additional pressure (usually 1.8-2.0 bar)

 

[vyv_cox]

Re: Calorifiers and Bukh engines

It is certainly a subject that has come up fairly frequently.

Yanmar engines have optional fittings that provide identical facilities to those of the Bukh - circulation by an external pump of coolant from the head/manifold to a low point on the block. I could have done this with my new Yanmar 27 but we decided on a fresh water cooled unit, mainly because it avoids the problem of adding antifreeze to the calorifier coils in the winter. I had a Yanmar 12 dating to about 1975 and this also had tapped plugs for the fitting of a calorifier.

Scalding is not really a problem, the water is little hotter than domestic hot water and considerably cooler than in industrial premises where temperatures are kept high for the avoidance of Legionnaires Disease.

The only requirement for thermal expansion is a relief valve attached to the calorifier. Most new units come with this included in the package. In practice mine has never lifted. I suspect the hoses to be sufficiently flexible to absorb the expansion. I fitted an accumulator soon after buying the boat, which may absorb some expansion, but for 10 years prior to that there was no extra provision for expansion. All hoses on my system, now 16 years old, are a mixture of unreinforced and reinforced flexible, of the type sold in every chandler.

We would be horrified if we used as much as 5 gallons per day between us (perhaps we wash less than most!) Our typical consumption is much more like your 1 gallon per day each, with pressurised hot and cold in galley and heads and a hand pump with charcoal filter for drinks.

 

[gus]

With a bit of thought and the right advice it should not be a problem. You need a calorifier tank (with a pressure relief valve) and if it is fitted with a immersion heater you can have it plugged into the pontoon lecky. You also need pressure actuating pump with an accumulator tank to stop overworking the pump. Plastic 'click together' piping works fine or you can use vehicle heater hose for the tricky bits. If you need an acc. tank let me know for I have a spare.