Jump to content

Producing Hot Water.


Chris J

Featured Posts

Hi All,

So, after a year of living aboard a boat that only generates hot water via running the engine and slowly warming up water in the calorifier which is all over in a hot minute. Ive decided that its time for some home improvements, mainly in the guise of hot water. 

My initial thought was Webasto, but I read very recently that they don't like to work as just water heaters and need to do central heating as well. Lovely in times like this but I don't particularly want to be heating the boat via rads in the middle of the summer every time I want to do the washing up. Other thing is the quite high cost or purchase and what ever parts of the install I cannot do myself plus regular maintenance.

Second thoughts a Morco gas boiler, but from what I see in the specs of the ones I've been looking at they only heat the water to 25C above the water temperature. Thats just not hot enough for most hot water requirements. Secondly I heard that BSS is wanting to phase out gas from boats so is investing is a gas boiler perhaps not wise.

Immersion heater, to be honest I've done little to no research. Just the huge power output has put me off even considering it as an option. However knowing that my battery bank needs replacing and a new solar array is on the shopping list maybe it could work. 

I guess what I'm asking is what from the above is myth, what people are using, what you find the pros and cons of your set ups are and how much they have cost you to purchase/install. 

I've got a fair bit of cash to spend on the batteries the solar and the water heating I just want to make sure I spend it wisely and don't regret it in a few months years down the line!

Look forward to hearing what you all have to say. 

Thanks in advance.

Link to comment
Share on other sites

Yes yes, very efficient way of heating water, I've got stacks of experience of using them. Mines even got a thermometer so I can regulate the temperature.. Not so good for the shower though. 

26 minutes ago, rusty69 said:

Bullit proof Paloma has been running for 19 years with no replacement parts needed (and it was second hand when we got it).Has been in daily use. 

 

If you have mains, I would go with an immersion.

I should add, I do not have mains.

Link to comment
Share on other sites

40 minutes ago, Chris J said:

Second thoughts a Morco gas boiler, but from what I see in the specs of the ones I've been looking at they only heat the water to 25C above the water temperature. Thats just not hot enough for most hot water requirements.

The increase of 25 degrees assumes the maximum flow rate through the Morco.  But that can be controlled.  Turn the knob down and you can (for example) have a 50 degree increase in temperature,  but at only half the rate of delivery.

Quote

Secondly I heard that BSS is wanting to phase out gas from boats so is investing is a gas boiler perhaps not wise.

Who on earth suggested that?  At least 90% of inland cruising boats must use gas for cooking.  There is absolutely no agenda I know of that to try and change that.  If you have it for cooking, hen it is clearly an option to also use it for water heating.

Edited by alan_fincher
Link to comment
Share on other sites

Webasto - on our boat, in the summer, all radiators are turned off and the webasto is on a timer.  30 mins in the morning 0630 to 0700 is enough to heat a calorifier full, for 2Xshowers and washing up etc.  

Its been set up like this for three years, and doesn't seem to have harmed the Webasto (Thermo top C)!

Link to comment
Share on other sites

It's those aircooled listers that's the issue, so we upped the alternator rating and put a 12v Rv water heater in which just has enough for a shower . Not brilliant but with a few hours running... you have to keep an eye on the alternator temperature though coz they are 300w at 12 v. Days we don't boat we have a solar shower. In the winter we run away to our Rv that has a superb built in shower system far better than the boat

 

Link to comment
Share on other sites

I know somebody who quite successfully heated up water from an air cooled Lister.

He wrapped a long coil of copper piping around the exhaust manifold and along the horizontal part of the exhaust pipe.

Each end he olive jointed (so he could disconnect if necessary) to a sealed system with expansion/filler bottle that in turn passed through a small calorifier in a domestic water tank thingy. It wasn't crazily effective but after a days hard boating he had a hot tank of water.

Running the engine a couple of hours a day made it tepid, perhaps a circulation pump might have helped, he did rely on thermosiphon and constructed it all to encourage convection with the tank higher than the engine. No kinks or changes in elevation, straight up to the tank, straight back down to engine. 

It took a bit of bleeding to get the air out, but he swore by it, and at it. 

Link to comment
Share on other sites

On 07/02/2018 at 16:44, Chris J said:


I guess what I'm asking is what from the above is myth, what people are using, what you find the pros and cons of your set ups are and how much they have cost you to purchase/install. 

I've got a fair bit of cash to spend on the batteries the solar and the water heating I just want to make sure I spend it wisely and don't regret it in a few months years down the line!

Look forward to hearing what you all have to say. 

Thanks in advance.

In the summer we are using the engine most days and enough water for a couple of showers and enough for washing up is generated by the engine  in one hour - but usually going for 4 hrs so lots of hot water. In the winter the stove  heats the boat but we run our eberspacher for an hour to heat the back of the boat and that heats the water. As someone said above, in the summer if you are not running the engine, just put the eber on for half and hour or so. From what you wrote, is the problem that your engine  isnt heating the tank fast enough?

In the winter we are in a marina quite a bit and we suppliment the hot water with an immersion but the eberspacher usually fullfills requirements.

no need for a separate gas water heater.....but useful if the eber packs in!!

Link to comment
Share on other sites

Like Dr Bob I ensured I had a large enough calorifier and most of the water heating is done by the engine.  The boat ha a different gas central heating boiler when we bought it that did all the hot water but when that leaked I fitted another gas boiler (Alde 2928) and a larger twin coil calorifier. In winter the gas boiler heats the water when the central heating is running and I can turn the radiator circuit off in the summer so the gas boiler can still heat water when needed.

I kept gas because  the reliability reputation of most diesel boilers and am happy t pay the higher running costs.  I think the 2928 cost around 500 or 600 quid. The calorifer maybe £200 or so (long time ago now).

I regret not getting a back boiler in my stove. If I had that would have provided a lot of water hr=eating in the winter.

NOTE: I think the Alde 2928 is obsolete and the later 3000 series can not be used with copper in the system say Alde because it can corrode the aluminium heat exchanger and perforate it.

 

Link to comment
Share on other sites

I have a calorifier (engine & mains immersion) and an instant gas water heater.

I have a kettle too. It was a tricky workaround, but unlike zenataomn, on my boat I found that there was actually no need to remove the gas water heater in order to place the kettle on the hob. 

Edited by blackrose
Link to comment
Share on other sites

Ideally for optimum hot water performance an instantaneous gas hot water heater needs to be fixed to a bulkhead in the galley which is directly adjacent to the bathroom and can feed hot water to both galley taps, bathroom shower and taps with the shortest possible pipe runs. 

  • Greenie 1
Link to comment
Share on other sites

1 hour ago, bizzard said:

Ideally for optimum hot water performance an instantaneous gas hot water heater needs to be fixed to a bulkhead in the galley which is directly adjacent to the bathroom and can feed hot water to both galley taps, bathroom shower and taps with the shortest possible pipe runs. 

Yes this is very good advice.

The shorter hot pipe run the better - that's a definite.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.