Boat gas and water pumbing guide

[Strettonman]

Can anyone point me to a good comprehensive guide to boat plumbing. I’m not going to fit a boiler but want to heat my water and radiators from the engine and a stove as we plan to use it for cruising rather than a live aboard (and i’m tight so always looking for something for free ?). I want to do it in a way that could add something like a wabasto at a later date. 

[blackrose]

How are you planning on heating your water from the engine without a boiler (calorifier)? I guess this is why you're looking for a guide.

 

I just googled this so it might be rubbish:

 

https://www.thefitoutpontoon.co.uk/plumbing/pipe-work/

 

[PaulJ]

As Blackrose says-you are going to.need a calorifier. You could also add a decent size heat exchanger to your heating circuit and use this to indirectly heat your rads with the engine. This would also work well when you put your diesel boiler in at a later date.

There was a member on here who put up some really good info on this on his blog-though cant remember name at the mo.

Added..

There ya go..

 

http://boatbuildblog.blogspot.com/2014/02/more-control.html?m=1

Edited March 2, 2019 by PaulJ

[WotEver]

55 minutes ago, blackrose said:

How are you planning on heating your water from the engine without a boiler (calorifier)?

Surely a ‘boiler’ is a gas or diesel powered water heater and a calorifier is a ‘hot water tank’?

[Strettonman]

Obviously I’m planning to use a calorifier (water tank) - just don’t want a gas boiler taking up precious interior space. 

 

I understsnd and most calorifier a come with twin coils and a small element so I can heat the water if I’m on elec hook-up (although that will be unlikely). 

 

The he plan is to use ine coil off the engine and the other off the stove but might need to think about how a wabasto might be plumbed in later. 

 

Thanks for the link. 

Sorry about all the typos- small phone and damn predictive text ?

[OldGoat]

56 minutes ago, Strettonman said:

Obviously I’m planning to use a calorifier (water tank) - just don’t want a gas boiler taking up precious interior space. 

 

I understsnd and most calorifier a come with twin coils and a small element so I can heat the water if I’m on elec hook-up (although that will be unlikely). 

 

The he plan is to use ine coil off the engine and the other off the stove but might need to think about how a wabasto might be plumbed in later. 

 

Thanks for the link. 

Sorry about all the typos- small phone and damn predictive text ?

Methinks you do misunderstand -

The calorifier is for heating the domestic hot water (from the engine and/or a Webasto (etc) )

It's 'unusual' to heat the radiators from the engine waste heat - who wants to run the engine to heat the boat in cold weather all day and all night?

To save a lot of hassle it's better to make the decision of how to heat the radiators from the beginning - before you do the plumbing - as your design considerations will be different...

[stegra]

Seems that you need a Webasto/Eber to one coil of the calorifier. That will provide hot water and also feed the radiators directly. Then you need to decide whether to use the second coil with the engine or the stove. I believe most folks have the engine but it could depend on your intended use of the boat. For instance if you cruise most days then it makes sense to use the engine heat for hot water. If you are permanently moored with shoreline and the engine seldom runs then the stove will be preferable. A stove circuit is likely to need a pump which presents a new set of challenges. 

 

The engine alone won't heat the whole boat, only provide a tank of hot water. If you are going to be using the engine to charge batteries it makes sense to heat the water at the same time. 

Edited March 2, 2019 by stegra

[system 4-50]

I got rid of my calorifier.  The effort of draining it for winterizing proved too much.  My Morco is much more convenient, though obviously it costs more if cruising.

[blackrose]

3 hours ago, WotEver said:

Surely a ‘boiler’ is a gas or diesel powered water heater and a calorifier is a ‘hot water tank’?

Yes, but boiler is a fairly loose term for the layman and hot water tanks are often referred to as boilers (perhaps incorrectly). A calorifier is a hot water tank but it still needs to be fired / heated either from the engine, stove or mains immersion. 

Edited March 2, 2019 by blackrose

[Sea Dog]

1 hour ago, system 4-50 said:

I got rid of my calorifier.  The effort of draining it for winterizing proved too much.

Mine's never been drained over its 10 winters, so I've decided to leave it where it is.  

 

(We don't live aboard,  but we use the boat too frequently in winter to be doing with the effort of draining it time and time again only to refill it soon afterwards.  Fingers crossed, eh?)

 

 

Strettonman, also take a look at @Tony Brooks of this parish's website (tbtraining) as there's lots of good stuff there. 

 

[OldGoat]

6 minutes ago, Sea Dog said:

Mine's never been drained over its 10 winters, so I've decided to leave it where it is.  

 

(We don't live aboard,  but we use the boat too frequently in winter to be doing with the effort of draining it time and time again only to refill it soon afterwards.  Fingers crossed, eh?)

 

 

Strettonman, also take a look at @Tony Brooks of this parish's website (tbtraining) as there's lots of good stuff there. 

 

Echo that -

Not drained my cauliflower in 20 years, HOWEVER I do open hot and cold taps, including the drinking water filter taps when I leave the boat.

[Strettonman]

My thinking is that as we will only be on the boat for cruising we will run the engine every day for a decent period. Therefore we should definitely use the engine to heat a tank of hot water for a couple of showers after a days boating and a bit of pot washing. 

If we need heat during the day or the evening we’ll fire up the stove so should use some form of radiators off this to distribute heat to the bathroom and bedroom (with or without a small quiet pump)That’s the basic obvious stuff. 

I guess the main question is whether I should use the second calorifier coil to top up the heat in the water tank during the cold evenings and over night. This coil I guess could be repurposed for a wabasto if we ever decide to live aboard. 

If I try to use the stove heat for either radiators or water heating am I a) going to compromise flow so much that I can’t hope to have a gravity system, b) is it appropriate to have a manual or powered diverter valve between Rads and tank (like home gravity or pumped CH systems) and c) is there a danger that if the stove isn’t on and I have a tank of hot water I will inadvertantly siphon out all the heat into the rads  over night. 

The idea of heating the tank from the stove as a second source appeals for the odd occasion we don’t cruise or the calorifier doesn’t hold the heat too well over night but am I setting myself up for compromising performance for these occasional benefits.

I also need to understand how quiet a pump I could get for the rads if I needed to. Need to think about disturbing those either sleeping in the bedroom or the lounge. 

[Jen-in-Wellies]

19 hours ago, blackrose said:

Yes, but boiler is a fairly loose term for the layman and hot water tanks are often referred to as boilers (perhaps incorrectly). A calorifier is a hot water tank but it still needs to be fired / heated either from the engine, stove or mains immersion. 

On CWDF calorifiers are always called cauliflowers.

 

21 hours ago, Strettonman said:

I understsnd and most calorifier a come with twin coils and a small element so I can heat the water if I’m on elec hook-up (although that will be unlikely). 

 

The he plan is to use ine coil off the engine and the other off the stove but might need to think about how a wabasto might be plumbed in later.

Cauliflowers come with one, or two coils as standard, or more if custom made. One coil is cheaper, but buy with two for future proofing. If you plan at all to have a solid fuel stove with backboiler, then make sure one of the coils is in large diameter tube as this makes gravity circulation easier to set up and no pump required. Depending on the manufacturer, some cauliflowers will be supplied with all fittings. Others will be bare bones and you can easily spend another hundred pounds on immersion heater, relief valve, mixer valve etc. Also, if it doesn't have an immersion fitted, make sure the boss for an immersion heater is present, even if it is buried under the spray insulation.

 

Jen

[Sea Dog]

25 minutes ago, Strettonman said:

Therefore we should definitely use the engine to heat a tank of hot water for a couple of showers after a days boating and a bit of pot washing. 

We generally shower when on the move where possible.  This means that the hot water used is replenished by the engine, such that we then have a full tank of hot water when we moor. Remember, it's not just that you take hot water out but also that you put cold water back in, after which the hot water remaining cools faster, although it sits at the top of the tank and the cold comes in at the bottom to minimise the effect.

 

If your cauliflower cools overnight to the extent that you have only tepid water by morning you may be suffering thermal syphoning through the cold engine block overnight.  Try swapping over the in and out pipes from the engine at the calorifier, and also ensure that those pipes go down to deck level before rising up. 

[system 4-50]

53 minutes ago, Strettonman said:

My thinking is that as we will only be on the boat for cruising we will run the engine every day for a decent period. Therefore we should definitely use the engine to heat a tank of hot water for a couple of showers after a days boating and a bit of pot washing. 

If we need heat during the day or the evening we’ll fire up the stove so should use some form of radiators off this to distribute heat to the bathroom and bedroom (with or without a small quiet pump)That’s the basic obvious stuff. 

I guess the main question is whether I should use the second calorifier coil to top up the heat in the water tank during the cold evenings and over night. This coil I guess could be repurposed for a wabasto if we ever decide to live aboard. 

If I try to use the stove heat for either radiators or water heating am I a) going to compromise flow so much that I can’t hope to have a gravity system, b) is it appropriate to have a manual or powered diverter valve between Rads and tank (like home gravity or pumped CH systems) and c) is there a danger that if the stove isn’t on and I have a tank of hot water I will inadvertantly siphon out all the heat into the rads  over night. 

The idea of heating the tank from the stove as a second source appeals for the odd occasion we don’t cruise or the calorifier doesn’t hold the heat too well over night but am I setting myself up for compromising performance for these occasional benefits.

I also need to understand how quiet a pump I could get for the rads if I needed to. Need to think about disturbing those either sleeping in the bedroom or the lounge. 

I get the impression from the above that you expect to be able to fire up the stove and heat rads from it quite quickly.  My experience is that lighting up the stove and getting some useful heat into the boat takes some hours, and I would expect heating rads with a back boiler to take even longer as they are not very powerful. I don't think it would be practical for, say, evenings only heating. What do other people think?

One other point, I believe my back boiler instructions say something about avoiding pumping until the water is hot enough, to avoid condesation/corrosion. I doubt many people bother about this but it might be worth reading up on before installing.

[OldGoat]

3 minutes ago, system 4-50 said:

I get the impression from the above that you expect to be able to fire up the stove and heat rads from it quite quickly.  My experience is that lighting up the stove and getting some useful heat into the boat takes some hours, and I would expect heating rads with a back boiler to take even longer as they are not very powerful. I don't think it would be practical for, say, evenings only heating. What do other people think?

One other point, I believe my back boiler instructions say something about avoiding pumping until the water is hot enough, to avoid condesation/corrosion. I doubt many people bother about this but it might be worth reading up on before installing.

I was just about to say as much as your comment, however with the addition that there's been no pointer about the need for a pump to circulate the hot water through the radiators and cauliflower. A thermo syphon is not going to work in a 'conventional' heating circuit.

 

In the spring / summer if we get wet or need more drying than the airing cupboard can cope with, we turn on the ebersplutter central heating. All the radiators have fiddle rails over them to hang wet clothes (etc) on them. I designed the boat and its systems on the old computer adage - KISS....  

[Strettonman]

I’m trying to keep it simple by avoiding having to fit an additional heat source which will require a link to an energy source (gas or diesel) an exhaust system, a burner and a pump. Clearly from an operator point of view flicking a switch to get hot radiators is easiest but I am trying to balance in my mind the compromise between that and the implications of  simpler system which potentially might not even need electricity. 

In terms of radiator heat up rates I’ve no problem waiting for the stove to get fully up to temp before the rads kick in. What may be an issue is that if the stove is hot and I open up a radiator it then takes a long time for it to get warm with a gravity system. Any idea how long a hot stove will take once you allow thermo syphoning ? 

10 mins would probably be fine but if it’s more like 30 mins I think I’d have to go for a circulation pump (which would mean the plumbing routes would be less critical). 

[system 4-50]

How many Kw are your expecting to get into your rads from the stove at full wack?

[Strettonman]

I don’t know. I need to work out radiator sizes and I am also looking to change the current stove for one with back boiler connections. The boat is only 40ft so I won’t need a big stove and the bedroom at the back will be the typical 6ft square (ish) so not masses of volume to heat. I will also put a small rad in the bathroom. 

Assume it is 2 rads of 4sq.ft total connected with 2 25ft runs of 22mm copper. 

I presume when buying the stove I can look at the output from the back boiler. At this stage I am just looking for a rough idea of how long it takes to get the hot water circulating fully through the rads so I can decide whether gravity will be good enough. 

[Strettonman]

Just done a rough calc and assume both rads would produce 3-4KW output. 

[OldGoat]

5 minutes ago, Strettonman said:

I don’t know. I need to work out radiator sizes and I am also looking to change the current stove for one with back boiler connections. The boat is only 40ft so I won’t need a big stove and the bedroom at the back will be the typical 6ft square (ish) so not masses of volume to heat. I will also put a small rad in the bathroom. 

Assume it is 2 rads of 4sq.ft total connected with 2 25ft runs of 22mm copper. 

I presume when buying the stove I can look at the output from the back boiler. At this stage I am just looking for a rough idea of how long it takes to get the hot water circulating fully through the rads so I can decide whether gravity will be good enough. 

Aha! - are you aware that if you are relying on a thermo syphon, then the design is a bit (a lot more) more than just laying pipes in a logical order.  There were threads on this forum some years ago, some were successful and those that were involved fiddling around with pipe sizes, straight pipe runs, and IIRC on one occasion had to resort to a pump for circulation. There were caveats about local boiling before the syphon got going. I thing it was just a radiator system with no hot water tank involved.

I'm not trying to pour cold water (sic) on your idea - but it's not as simple as you think and adding an Ebersplutter later might involve some re-design.

 

[David Mack]

2 hours ago, Strettonman said:

Any idea how long a hot stove will take once you allow thermo syphoning ? 

10 mins would probably be fine but if it’s more like 30 mins I think I’d have to go for a circulation pump (which would mean the plumbing routes would be less critical). 

 

24 minutes ago, Strettonman said:

 The boat is only 40ft so I won’t need a big stove and the bedroom at the back will be the typical 6ft square (ish) so not masses of volume to heat. I will also put a small rad in the bathroom.

 

For a boat that size the stove alone will heat the boat up pretty quickly, and radiators will only really be needed to top up the heat in the bedroom and bathroom, so heat-up time is unlikely to be critical. Best if you locate the stove fairly centrally in the boat though, rather than the often seen position right at the front of the cabin.

[system 4-50]

I believe my 5Kw SF Puffin stove is only capable of putting ~1Kw through its back boiler.  I own the BB but I've never fitted it.

[Strettonman]

Thanks. You are right about how much heat we need. The current stove gets the front of the boat pretty toastier but I need to move the heat down to the back. We plan to have a full width bathroom arrangement so even one of those stove fans won’t move enough hot air to the back. The bedroom rad is to take the chill off when going to bed and getting up so 1KW may be fine. I will make sure I investigate back boiler output when we replace the stove. 

 

Cheers

[Murflynn]

https://www.amazon.co.uk/Narrowboat-Builders-Book-Graham-Booth/dp/1870002717