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Is there anything wrong with cold water system Im proposing - as per CAD drawing doodle below ?. What was previously on boat makes no sense to me - I think it was copied from Surecal advice a little too literally and involves cold water from tank to calorifier at back of boat and then back up all the way along the boat again !? - is there a good reason for doing it this way that Im missing ?. 

cold.water.system.jpg

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8 minutes ago, matty40s said:

You will find out why the first one works when you take a shower wanting hot water at a consistent temperature and pressure with your design.

?

Yes ... getting x1 pump to feed cold to shower and cold-in & hot-out to calorifier does concern me, but thats the way most people seem to do. Manufacturer advice is to tee off cold for shower before cold in to calorifier (see here), which is what Im proposing. Wouldnt a good quality thermostatic mixer valve on shower cope ??

 

(I can run electrics anywhere so thats not an issue for me. I want pump at bow because noise as bed will be at back.)

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5 minutes ago, Sassy Lass said:

Yes ... getting x1 pump to feed cold to shower and cold-in & hot-out to calorifier does concern me, but thats the way most people seem to do. Manufacturer advice is to tee off cold for shower before cold in to calorifier (see here), which is what Im proposing. Wouldnt a good quality thermostatic mixer valve on shower cope ??

 

(I can run electrics anywhere so thats not an issue for me. I want pump at bow because noise as bed will be at back.)

Do you run your pump while you are in bed?

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4 minutes ago, Sassy Lass said:

I often get up hours before wife ... want to be able to run taps etc without waking her 

That'll confuse him, SassyLass has a wife.

 

The system you propose has the shower cold feed taking the most of the pressure from the pump before the calorifier, never mind the return journey the hot water has to make.

...and if someone touches another tap in the boat while someone is in the shower, I can hear the screams already.

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yes, I think its pressure issue. Webasto / Isotemp suggest same layout. Want tee at calorifier to split pressure equally to hot and cold demand (ideally). So Im thinking  go with the tried and tested (no great prob running 3 pipes up and down boat), but what about -- https://www.bes.co.uk/water-pressure-equalising-valve-16711 ???

webasto.setup.jpg

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ok think I know whats happening...its the TMV.  Sigmar Marine, Vetus and Webasto suggest what I was proposing (note past tense !) is okay iff no TMV. (see vetus setup 7 vs 9). But that makes me more confused about SureCal (which is what Ive got), their advice is to tee off for shower before calorifier ?? ?

sigmar.jpg

vetus.jpg

surecal.png

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On Legacy we have the system you wish to go onto. It works without a problem as we have learned to say when going for a shower and the others onboard know not to open a tap wide. Slowly to fill a kettle is fine.

 

Because, like me, you have a dislike of the pump running whilst the other half is in bed I have fitted a second accumulator (only because I was offered it for free) and so have about 4 litres available before the pump cuts in.

 

I have just mounted the pump onto a solid concrete base (old thin paving slab) and connected said pump to the pipework with long flex hoses. Big reduction in noise but can still be heard throughout the boat. Pump fitted is a Jabsco Par Max     31620-0292       4.3/16.3

 

Dave

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30 minutes ago, DaveR said:

On Legacy we have the system you wish to go onto. It works without a problem as we have learned to say when going for a shower and the others onboard know not to open a tap wide. Slowly to fill a kettle is fine.

 

Because, like me, you have a dislike of the pump running whilst the other half is in bed I have fitted a second accumulator (only because I was offered it for free) and so have about 4 litres available before the pump cuts in.

 

I have just mounted the pump onto a solid concrete base (old thin paving slab) and connected said pump to the pipework with long flex hoses. Big reduction in noise but can still be heard throughout the boat. Pump fitted is a Jabsco Par Max     31620-0292       4.3/16.3

 

Dave

Thanks Dave, Cant tell you how helpful that is to know someone has tried this setup in practice and got it working  !!. Im going to set about it today. I'll do it as an 'experiment' and report back here if there are problems, but the advantages are: (i) K.I.S.S. -  easier to work out whats happening if goes wrong ?, (ii) Fewer connections / pipe joins - got to be a good thing, (iii) Because of (ii) a bit cheaper, (iv) Cant be totally bonkers because some manufacturer's recommend it, (v) Should be safe / no scalding risk if I use a thermostatic mixer on Shower which Im going to (I know lots dont and just use two standard taps becuase there's a TMV on the calorifier but I want to keep have separate regulation of shower temp)

 

How have you mounted pump to concrete slab - have you drilled and then used insert nuts ?

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If the system works at the moment, why not just move the pump to the tank and leave the rest as it is? That way you will retain equal pressure to the shower which will be best for operation. It is not a case of scalding so much as a cold shower.

Edited by Ex Brummie
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11 hours ago, Sassy Lass said:

I often get up hours before wife ... want to be able to run taps etc without waking her 

Get a proper sized accumulator (25litres) then you will be able to. I can draw off 15+ litres before pump kicks in, but then it does run for the best part of 2 minutes.

Edited by Loddon
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1 hour ago, Sassy Lass said:

Thanks Dave, Cant tell you how helpful that is to know someone has tried this setup in practice and got it working  !!. Im going to set about it today. I'll do it as an 'experiment' and report back here if there are problems, but the advantages are: (i) K.I.S.S. -  easier to work out whats happening if goes wrong ?, (ii) Fewer connections / pipe joins - got to be a good thing, (iii) Because of (ii) a bit cheaper, (iv) Cant be totally bonkers because some manufacturer's recommend it, (v) Should be safe / no scalding risk if I use a thermostatic mixer on Shower which Im going to (I know lots dont and just use two standard taps becuase there's a TMV on the calorifier but I want to keep have separate regulation of shower temp)

 

How have you mounted pump to concrete slab - have you drilled and then used insert nuts ?

I just drilled, used rawl plugs and gently screwed the pump down. Oh yes, I also added some felt pad feet under the slab - just because I have them.

 

I made the mistake of fixing the cold water pipe to the bulkhead using standard pipe fixers. Big mistake as the bulkhead was just one loud sounding board. Took them all off. The other thing I have done is to use standard pipe insulation where the cold pipe goes through the bathroom bulkheads on the way to the calorifier.

 

I am off to the boat next week and can take photos if you wish.

 

Dave

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12 hours ago, Sassy Lass said:

Is there anything wrong with cold water system Im proposing - as per CAD drawing doodle below ?. What was previously on boat makes no sense to me - I think it was copied from Surecal advice a little too literally and involves cold water from tank to calorifier at back of boat and then back up all the way along the boat again !? - is there a good reason for doing it this way that Im missing ?. 

cold.water.system.jpg

Your proposed layout looks fine to me. It's what I've got and I've never had any problems with it. One pump at the bow pressurising the entire cold and hot system with calorifier closer to the stern and shower roughly in the middle of the boat. Assuming this is all 15mm dia pipe then a full bore cold tank isolator might help the pump draw water from the low pressure side of the system. I also have an isolator on my accumulator (lots of people don't) but if you do have any suspected leaks then closing that isolator makes listening for leaks a bit easier.

Edited by blackrose
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Ours is much the same as your proposed layout. Cold water from Flojet 2.4 bar pump, no accumulator, runs down the lhs of the boat. the shower is the first thing, followed by toilet and bidet. Pipe runs down to the back of boat and up the other side to the calorifier, wash basin and kitchen sink. Hot water for the shower runs back down the rhs and round the back and up to the shower. We have a Grohe thermostatic shower valve. It is a Surecal calorifier but I removed the TMV as its maximum setting was 65 degrees so by the time it got back to the shower it had lost some of its heat. However we do have a TMV fitted to the wash basin as it's only 2 feet from the calorifier.

 

As an aside, is there any reason why well insulated pipes couldn't be run under the floor from one side of the boat to the other? Would it get cold enough to freeze?

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3 hours ago, DaveR said:

 

 

Because, like me, you have a dislike of the pump running whilst the other half is in bed I have fitted a second accumulator (only because I was offered it for free) and so have about 4 litres available before the pump cuts in.

 

I have just mounted the pump onto a solid concrete base (old thin paving slab) and connected said pump to the pipework with long flex hoses.  

 

Dave

A good move in my opinion, I also have two, but one is quite small but can still fill a kettle with no problem. The pump is not fixed down at all as it sits in a plastic meat tray (for when it leaks) on a paving slab (ballast) but also has hoses connections both sides.

46 minutes ago, pearley said:

 

 

As an aside, is there any reason why well insulated pipes couldn't be run under the floor from one side of the boat to the other? Would it get cold enough to freeze?

Mine do and over 2 foot below the canal surface are unlikely to freeze, the only pipe I have had freeze as in the toilet about 18" above floor level

Edited by ditchcrawler
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3 hours ago, Sassy Lass said:

  Should be safe / no scalding risk if I use a thermostatic mixer on Shower which Im going to (I know lots dont and just use two standard taps becuase there's a TMV on the calorifier but I want to keep have separate regulation of shower temp)

 

If you dont plan to live on the boat in the winter make sure you can fully drain the mixer valve of the shower for frost protection.

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On 27/04/2019 at 09:44, Sassy Lass said:

Thanks Dave, Would be interested to see photos.

 

Brummies, Unfortunately Ive removed everything !. Current state of boat as per photo below from last weekend ?

IMG_20190422_173238.jpg

1293473936_20190429_140031(Medium).jpg.fa87f751f6a23967afa2bdcd178aff93.jpg312766076_20190429_140021(Medium).jpg.926d5c45b6e2c9a7e15239f42d5f4450.jpg2087399759_20190429_140039(Medium).jpg.6e14b2ab0644dca99aa2da544dffca7b.jpg2087399759_20190429_140039(Medium).jpg.6e14b2ab0644dca99aa2da544dffca7b.jpg

 

The pump lives under the sink unit with a wood box ontop with some sound proofing installed.

 

Your boat is looking superb.

 

Regards

 

Dave R

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Thanks Dave.

 

Thats a very neat setup !. Have you had any problems with 1/2" BSP female hose to male plastic Jabsco pump port insert connection ? - When Ive looked at my mine it looked like a likely point of weakness. So much effort on these things and then it all hinges on a 2p piece of plastic !!.

 

Im off now to the hunt around the darkest recesses of the garden shed for a perfect sized concrete slab so I can copy you !... 

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