calorifier

[arthor]

Greetings all and before I ask this, excuse me for being a bit thick if it appears that way.

I have a Fjord 27 and am doing a bit of work on it this year. She has an inboard diesel and I am thinking of getting a calorifier with a 240v immersion for when we are hooked up to shore power.
At the minute she has a couple of gas heaters and an instant gas hot water heater and I am not keen on the idea of them and want to remove them. The taps are electric and when turned on, they produce hot or cold water. I am wondering if the taps themselves have little pumps in them or am I being stupid. If they do, then I am asuming I can leave them in and they will be ok with dragging water out of the calorifier or cold system as they are doing now. Does that sound logical?
If I am wrong about the taps then I am happy to put a new layout in from scratch. What is the usual system? Would I need a pump and would it react to a normal tap being turned on? If the calorifier is quite low down and the tap/showerhead is quite high up, I can't work out what would apply pressure to the water to get it to the tap. What is the usual method for tackling this?
If anyone can give guidance or help on this then I would be very grateful.

Thanks in anticipation

arthor

 

[carlton]

I have a Fjord 27 and am doing a bit of work on it this year. She has an inboard diesel and I am thinking of getting a calorifier with a 240v immersion for when we are hooked up to shore power.
At the minute she has a couple of gas heaters and an instant gas hot water heater and I am not keen on the idea of them and want to remove them. The taps are electric and when turned on, they produce hot or cold water. I am wondering if the taps themselves have little pumps in them or am I being stupid. If they do, then I am asuming I can leave them in and they will be ok with dragging water out of the calorifier or cold system as they are doing now. Does that sound logical?

Hi arthor - sounds as though you already have a pump fitted in your FW circuit - otherwise the water wouldn't reach the taps from your onboard water tank.

If I am wrong about the taps then I am happy to put a new layout in from scratch. What is the usual system? Would I need a pump and would it react to a normal tap being turned on? If the calorifier is quite low down and the tap/showerhead is quite high up, I can't work out what would apply pressure to the water to get it to the tap. What is the usual method for tackling this?
If anyone can give guidance or help on this then I would be very grateful.

Sounds as though you'd have to modify your current set up. This is a typical installation diagram...

 

[Cliveshep]

Carlton is giving you very good advice but if you have "electric" taps it might well be that you only have a caravan type system with a small pump which is turned on by the micro switches in the taps. I suspect that you only get a small flow of water as well if that is indeed the case.

Fitting a pressurised water system, which is what Carlton has (quite correctly) drawn for you utilises a pump with a pressure switch built in which is why he also shows a pressure vessel to prevent the pump needlessly "cycling" when you only want a cup or so of water. The advantage of a pressurised system is you can then fit any household mixer tap, basin tap, shower mixer and flow rates are far greater.

 

[arthor]

Many thanks for the responses. I like the diagram Carlton and can already see it in situ.

My take on it then is this. The water (hot) in the calorifier is already pressurised before it gets there and it is this pressure that forces the water out of the calorifier and the pump pulls water from the cold tank?

That system looks fine to set up from scratch. I take it the pump is 12v? What sort of size accumulator tank would I need? What size calorifier would I need if I were going to run central heating from it? I would guess maybe three little radiators/heating units. Are there special marine central heating radiators? I take it I would need another pump to push the water round the central heating? Lastly, most of the piping seems to be household looking stuff. The blue and red stuff like washing machine hoses. I like the idea of bright red and blue to keep track of where stuff is. Is this piping ok and does it come in 'by the metre' lengths and could I just join it together with plastic connectors.

thanks again

arthor

 

[carlton]

My take on it then is this. The water (hot) in the calorifier is already pressurised before it gets there and it is this pressure that forces the water out of the calorifier and the pump pulls water from the cold tank?

Look at the diagram I posted. The water in the (blue) tank is not pressurised. When the pump is activated (by the pressure switch which senses any drop in pressure - i.e., when you open a tap) the pump pulls it out of the tank and then everything after the pump is pressurised, including the contents of the calorifier.

That system looks fine to set up from scratch. I take it the pump is 12v? What sort of size accumulator tank would I need? What size calorifier would I need if I were going to run central heating from it? I would guess maybe three little radiators/heating units. Are there special marine central heating radiators? I take it I would need another pump to push the water round the central heating?

Pumps are available either 12 or 24 volt. It's up to you whether or not you use an accumulator - they're used to stop the pump 'pulsing', i.e. cutting in repeatedly for small drops in pressure. Central heating? Yes, you'd need an additonal (circulating) pump, but you're going to need a big calorifier and, more importantly, a big immersion heater element to keep up with the heat lost from any radiators if you're running heating on shore power. Possibly more than your shore power will allow. That's probably a non-starter, unless someone on here knows better?

Lastly, most of the piping seems to be household looking stuff. The blue and red stuff like washing machine hoses. I like the idea of bright red and blue to keep track of where stuff is. Is this piping ok and does it come in 'by the metre' lengths and could I just join it together with plastic connectors.

Chandlers, and camping/caravan suppliers sell the FW pipe by the metre together with the connectors.