Fitting a pressurised water system and hot water?

[Matt341]

Hi All,

We have a 28 foot Mirage and recently have been looking at upgrading to something more comfortable for staying onboard. Came close to buying a Konsort but after reading the recent survey and comparing with others we felt she was overpriced and needed some expensive work doing.

So have decided to stick with the Mirage and to do some improvements.

A while back I did a post about everything that would need doing to make her comfortable for staying on and now that the shorepower has been professionaly sorted, fridge fitted and new upholstery I feel ready to tackle the water system.

There is a large water tank at the bow of the boat which is in good condition and I dont really want to change it, there are then 2 pipes coming from it, one feeding the heads sink, the other to the galley sink.

If at all possible I would like to keep this system as it is so when on anchor we can still use it to save on battery use.

I have a rough idea of what should be fitted -
pipe from tank straight to water pump, 3 way split, 1 to mixer tap in heads, 1 to galley tap and the other to calorifier? 2 Hot water pipes then come from calorifier, 1 to galley and 1 to heads?

I do have a few questions though, what pump should be fitted? I would rather go for pressure system as opposed microswitch, can I buy a Whale submersible water pump to put into water tank and then fit pressure switch to control pump or should it be something like the Shurflo Trail King?

I have been given mixed advice, some people say I should have a pump for cold water system and pump for hot water system, on the motorhome we only have 1 pump for both hot and cold but maybe a yacht system is different?

I also dont want to spend a fortune on the job.

Also what is the best Calorifier to use? The engine is a 2006 Yanmar 2GM20, how simple is it to connect the calorifier to it.

I look forward to your advice.

Many Thanks
Ian

 

[fireball]

Hmm - lots of questions!!

I guess you currently have manual pumps at the taps - which is why you're looking at pumps.
We only have one pump - this pumps into an accumulator tank which pressurises the system - the pump has an automatic pressure cutoff so it only runs when the pressure is below a set level.
This feeds the three taps and the calorifier - which also feeds 3 taps.

I don't think you need a submersible pump - you should be able to put one inline - ours is around 3 foot above the top of the tank and self-primes.

The best calorifier is the one that fits into the space available!! It needs to be near the engine and I'd suggest getting one that you can fit an immersion element to as well (mains powered).
The Yanmar 2GM20 is direct water cooled - ie it passes raw water around the engine, rather than having a freshwater tank and heat exchanger. It is capable of running a calorifier, but it isn't going to make hot hot water.
iirc the calorifier sat between the pipe that comes off the top of the thermostat housing and returns to the exhaust elbow - I've got the workshop manual somewhere online - pm if you want a (soft!)copy

 

[philip_stevens]

Following on from what Fireball says about the calorifier .... get one with two heating coils as well as the immersion heater. This is if you ever upgrade and fit an Eberspacher Hydronic heater, that will give you hot water for radiators or a matrix air blower, as well as heating the calorifier. This is the system we have fitted in our Duo.

 

[Matt341]

Many Thank for the replies,

I only have one question left now, Will I need to drill another hole in the tank for the pressurised feed pipe OR where the pipe comes out of the tank at the moment could I put a Y split in it and possibly a non return on the manual line incase the water from the manual system flooded back into the pump or is that not necessary? The Y split wouldnt be pressurised because it is before the pump.

Also, I assumed that all calorifiers had an immersion element fitted for shorepower but will now check just incase.

Any recommendations on a good pump? would it need to be something big like the Shurflo or could it be something as simple as this - http://www.towsure.com/product/2611-Whale_In_Line_Pump_925

Many Thanks
Ian

 

[fireball]

I thought the idea was to replace your manual system?

You'll always get leaks through a non-return valve so if it was me and I really wanted to keep the manual system as a backup then I'd put a y valve in place.

I think you may be better off looking at something like this: http://www.marinesuperstore.com/posit/shop/index.php?selectedpartno=PARMAX

 

[Matt341]

Thanks for the reply, as stated in the intial thread what I was hoping to do was to keep the manual system as it was so to save on power when on anchor.

A Y valve is another option because the Y would be close to the toilet seacocks which are easily accessible so wouldnt really be a problem to switchover if needed.

I have done a rough sketch of what would be needed etc, my main concern is that there will be a cold water pipe running from the bow to the stern nearly, then into the calorifier and the one of the hot pipes from the calorifier will have to run all the way back upto the heads, this will be about 30foot in total which then makes me wonder if a booster pump would be needed?

Ian

 

[fireball]

just had a look here: http://www.ittjabsco.com/products/c...systems/pressure_system_accessories/index.htm

The accumulator tanks can run up to more than 8 bar ... I don't think you'll need a booster pump if your taps & pipework are well fitted.

 

[Strathglass]

Thanks for the reply, as stated in the intial thread what I was hoping to do was to keep the manual system as it was so to save on power when on anchor.

A Y valve is another option because the Y would be close to the toilet seacocks which are easily accessible so wouldnt really be a problem to switchover if needed.

I have done a rough sketch of what would be needed etc, my main concern is that there will be a cold water pipe running from the bow to the stern nearly, then into the calorifier and the one of the hot pipes from the calorifier will have to run all the way back upto the heads, this will be about 30foot in total which then makes me wonder if a booster pump would be needed?

Ian

I'll try and answer all your questions. No reason for not keeping your manual system as well.

There is no problem with a long run from the tank to your pump as long as there is not a big increase in the height. Why not mount the pump beside the front water tank?

When you buy your calorifier you will be supplied with fairly detailed fitting instructions. They will show you where to fit non return valves, presure release valves, expansion tank etc.

You will not be supplied with an immerser element with the calorifier unless you order it as an extra.

A normal domestic immerser is too powerful for a marine instalation and may end up tripping the marina circuit breaker. So you need to get a lower powered 'marine'one.

I would look at the ASAP site They stock all the bits you will require and will answer any questions you may have.

I find that the 6 gallon tank is about the best size compromise for your size of craft.

I will have a bit more time available after the weekend and be able to email you detailed drawings etc.

I am quite tied up just now as I am planning to launch my home built yacht for the first time on friday (after many many years work)

If you have ant immediate questions PM me and I will answer as soon as I can

Cheers

Iain

 

[Cliveshep]

Thanks for the reply, as stated in the intial thread what I was hoping to do was to keep the manual system as it was so to save on power when on anchor.

A Y valve is another option because the Y would be close to the toilet seacocks which are easily accessible so wouldnt really be a problem to switchover if needed.

I have done a rough sketch of what would be needed etc, my main concern is that there will be a cold water pipe running from the bow to the stern nearly, then into the calorifier and the one of the hot pipes from the calorifier will have to run all the way back upto the heads, this will be about 30foot in total which then makes me wonder if a booster pump would be needed?

Ian

Guessing from what you have already said perhaps the sketch here is how you want to do it?

View attachment 175

 

[claymore]

water system

Did this last winter so still fresh in the mind
I agree with all that has been said and would add 3 points
1) I bought the vetus pump unit which is really good and reasonably priced
2) I kept a manual pump in case of a catastrophic electrical failure (I'm no electrician)
3) I worked out that using a pressurised system we will inevitably use more water - simply running it until the hot comes through for example - so I had an extra tank fabricated and sat it low down in the bilges on the centreline.

Finally you might consider teeing off and running a feed through a filter for adding to the whisky.

 

[steve28]

is your engine a fresh water cooled one or a raw water version ?



Steve

 

[fireball]

the 2GM20 is raw water cooled unless it's been user modified ...

 

[Matt341]

Thank you for the replies, seems that once I have all the correct items it should be fairly simple to fit.

The engine was new from Yanmar 2006 and is Freshwater cooled, I have to top up the anti freeze over winter which is a right pain in the a** to get at, lol! However, it also uses sea water for part of the cooling process but when bought was classed as a freshwater cooled.

Going to investigate water pumps now, is it absolutely necessary for an accumulator? What is its purpose?

Many Thanks
Ian

 

[fireball]

R u sure its not a 2GM20F?

 

[steve28]

yes you need an accumalator or the calorifier will expand and possibly burst if you use an elctric pump.

i have a retro fitted freshwater cooling system, it works brilliantly if your motoring, i find that if you need hot water at pontoon it takes ages.