Manually pumped hot water

JumbleDuck

JumbleDuck

Well-Known Member
Joined
8 Aug 2013
Messages
24,165
Location
SW Scotland
Visit site
Given that I am in the middle of having a nice new Nanni engine fitted, which could heat some water for me, but that I have absolutely no intention of fitting a pressurised water system, is there any reason why I could not fit an unpressurised one ... pipe from water tank to calorifier, pipe from calorifier to pump at the sink?
 
How are you going to persuade the water in the tank to flow to the calorifier and thence to the sink ? Gravity doesn't seem reliable in a tilting boat, so it's either a manual or electric pump to push or suck. An electric one upstream of the calorifier will be running in cold water; downstream in hot. I can't recall having seen a manual H water pump.

One advantage of a pressure vessel is that you can draw a cupful of H or C water without a noisy pump waking people. Is it space that's stopping you installing a pressure unit ?
 
Last edited:
sarabande said:
How are you going to persuade the water in the tank to flow to the calorifier and thence to the sink ? Gravity doesn't seem reliable in a tilting boat, so it's either a manual or electric pump to push or suck.
Click to expand...

Yes - he's proposing a manual pump at the sink, sucking :confused:

A manual pump pushing through the calorifier should definitely work, the principle is the same as the standard electric system. A manual pump sucking? Can't see why it shouldn't...

Pete
 
sarabande said:
How are you going to persuade the water in the tank to flow to the calorifier and thence to the sink ? Gravity doesn't seem reliable in a tilting boat, so it's either a manual or electric pump to push or suck.
Click to expand...

Manual pump at the sink was my idea, just like the cold water.
 
You have made me think. I added a foot pump te'ed off so as to be able to draw water if the electrics or the pump went down. Now you have me thinking whether the foot pump should have been in-line and would push through the hot water as well.
 
Is it such a big deal to fit a pump? My system is just a Jabsco pump with a pressure cut off at 25psi, pipe to calorifier and pipes to taps. Cost me about £50 to replace the pump two or three years ago. I've seen some cheaper copies from China too since.
 
Instead of a pressure system why not use caravan taps with built in micro-switch and a cheap non pressure pump and do it that way with the pump between tank and calorifier.
Sucking from the sink won't do the job.
 
Boiling a kettle takes no time at all. I would not bother with the calorifier or hot water tank on a small boat. The store of hot water gets used up very quickly and it is a breading ground for stuff unless kept very hot. Obviously need to confirm that manual pump temperature rating is good enough for hot water system - likely it will be but you never know, low temperature O rings (elastomers) are cheaper than high temperature ones, so not an automatic assumption. Personally, I would not bother, not worth it for any perceived gain compared to kettle.
 
There is no reason at all why a positive displacement pump at the sink will not draw water through the calorifier. Once it is full it will remain so, being heated, until it is required. One of those dreadful vertical Whale manual pumps will draw a head of at least a metre, (although half of the water will leak out through the seals) and would be fine. A foot pump would be better still but more expensive.

However, the microswitch taps as suggested by PCUK work well, I have them on my motorsailer, with a little centrifugal inline pump that cost about £30. It pumps from the bilge to the calorifier that is at head height, best part of two metres. It supplies the heads and the galley, the dual mixer taps (H&C) were around £50.
 
BlowingOldBoots said:
Boiling a kettle takes no time at all. I would not bother with the calorifier or hot water tank on a small boat. The store of hot water gets used up very quickly and it is a breading ground for stuff unless kept very hot. Obviously need to confirm that manual pump temperature rating is good enough for hot water system - likely it will be but you never know, low temperature O rings (elastomers) are cheaper than high temperature ones, so not an automatic assumption. Personally, I would not bother, not worth it for any perceived gain compared to kettle.
Click to expand...

I disagree. Often just the running of the engine for getting the sails down, up the channel and into the berth can be enough to heat enough hot water to wash the dishes. The kettle can be reserved for more important things, like a cup of tea.
 
lpdsn said:
I disagree. Often just the running of the engine for getting the sails down, up the channel and into the berth can be enough to heat enough hot water to wash the dishes. The kettle can be reserved for more important things, like a cup of tea.
Click to expand...

Sure, but the volume is still limited, the kettle is far more productive. I ran a 10 berth sail training yacht with just a cold water system (manual pumps) and a large kettle. I just don't think it improves productivity enough to warrant the installation of a hot water system on the small boat that the OP has.

On my own boat I have the calorifier and hot water tank, with electrical immersion heater. I can store quite a few gallons of hot water and when on shore power, there is always lots of hot water available. However, when at anchor, any hot water is used up quite quickly and it is far more productive to boil up a kettle than run the engine.
 
prv said:
Yes - he's proposing a manual pump at the sink, sucking :confused:

A manual pump pushing through the calorifier should definitely work, the principle is the same as the standard electric system. A manual pump sucking? Can't see why it shouldn't...

Pete
Click to expand...

I presume you would need a thermostatic mixing valve on the calorifier, and that that would still work satisfactorily in the 'suck' configuration?
 
lpdsn said:
It is, but it is still very convenient to get the dishes started as soon as you get in on a Sunday evening rather than having to boil up the kettle a few times. My calorifier is 22l, kettle is <2l.
Click to expand...

That's my view. It's the ability to quickly do the boring stuff like washing up that makes a difference!
 
I agree, it is nice having hot water on tap. If it’s a single galley outlet you won’t ‘lose’ as much water as with a longer run forward to a heads basin as well, but I reckon you’ll probably end up using a bit more water overall. But the calorifier capacity itself offsets that a bit of course.
 
BlowingOldBoots said:
Sure, but the volume is still limited, the kettle is far more productive.
Click to expand...

The tank may be smaller than a domestic one, but it's a damn sight bigger than the kettle! It also operates entirely automatically, the hot water is just "there" without having to do anything, which makes a big difference.

We used to have just a manual cold tap on our previous boat, hot running water on the new one is quite a big part of why she feels more civilised to live on board. When we stay on a mooring or at anchor for more than one night, and have to resort to the kettle to wash up the second dinner, it's noticeably more of a faff.

Pete
 
I'd definitely opt for a calorifer as the best upgrade from a 'primitive boat'.
1) It saves a lot of gas. Which is £££ for camping gaz. And the hassle of looking for refills.
2) There is a lot more hot water. You can wash yourself and clean the boat properly.

Any pump with a non return valves should be OK.
Only issue I can see is that the water will expand as it's heated and spit hot water out of the tap.
And while you're about it you will want HW in both galley and heads.
It start to look like the full system is standard for good reason?
 
You must log in or register to reply here.

Other threads that may be of interest

D
No Raw Water Strainer - Trapper 500 Nanni 2.14
Replies
3
Views
204
Dulaman66
D
O
One for the plumbers
Replies
9
Views
376
Overandunder
O
ianc1200
Sureseal shaft seal.
2
Replies
20
Views
507
ianc1200
ianc1200

Share this page

Top