Calorifiers - Copper Vs Stainless Steel?

[floydraser]

I am thinking about replacing the gas water heater with a calorifier which brought about the following contest:

In the blue corner weighing in with a good reputation on this forum, is ASAP with their copper calorifier including thermostatic link.

And over in the red corner is Brian Ward with a similar weigh-in and his stainless steel jobby, thermo valve extra.

On paper (money) it’s a pretty even match and the only way I can separate them is by the fact that one of them is next to a pub. I would like to end up having done a decent job and added to the desirability and practicality of the boat.

I want a clean fight, stay above the belt and no head clashes. Ding ding!

The Cointra gas water heater was fitted for livaboard purposes by a PO with a daft looking chimney just where you don't want to see it (the boat has the chimney, not the PO). I've got the safety ticket due next year but even so, I would feel better if I stripped out the old gas piping from ex-fridges etc. and just had a straight run to the cooker. Unless someone can convince me otherwise?

Floyd.

[D46]

Copper tanks have always been a good choice on boats for many years , that said I can't see any reason not to chose a S/S one , the thermostic link is a different issue , do you really need it ? If you have mixer taps then probably not as there's no need to reduce the hot supply at the colirifier when it can easily be done at the taps .

Gas pipe wise if you have Tee's that are capped off with proper fittings it will no doubt pass s BSS , but it would be far better to replace the entire line working to the BSS guidelines if that indeed is a task that can be reasonably easily accomplished .

If doing the work yourself then before using it it's very prudent to get a gas safe engineer to pup a manometer on the system to test for pressure drop ie leaks .

[VetChugger]

Might be talking rollocks (often do!)  but are either of them insulated??? Mine had quite a thick polystyrene?? covering. I also ensured it came with an emersion heater which was eventually wired into the 240 circuit..

[scaniaman]

Pub wins every time. 

[Smoggy]

Copper has the advantage of killing bugs where stainless doesn't, the victorians didn't use bronze door fittings in hospitals for fun....(now we use stainless and have mrsa problems)

The one with the thermostatic link sounds like the sure-cal one I had on my last boat (I think they are the same as asap call hot-pot) which was a good well insulated calorifier, had a blue skin over the insulation with stainless mounting bands if that sounds familiar, I'd go for another if I need one (I will sometime as mine has flipped the base inside out due to heftier pump).

[JanetAnne]

Copper for its bug resistance as Smoggy has already said though stainless is much stronger.... I have also come across copper cylinders with their bases popped.

We all have stainless water tanks after all.

Actually it's a very good question. I tend to opt for stainless tank with copper cylinder and all copper pipework. That gives good heat retention and an excellent flow rate. I have never considered a s/s cylinder so am also interested in the forum's thoughts.

[annv]

Hi Floyd I prefer copper as easier to repair and doesn't crack with vibration unlike stainless, yes replace your gas piping, would suggest you get the plastic coated copper pipe and fit a bubble tester so you can test for gas leak at will and it will save the boat tester from having to undo a connection to test for gas leaks, should be part of regs in my opinion. John

[MauriceMynah]

25 minutes ago, annv said:

and fit a bubble tester so you can test for gas leak at will and it will save the boat tester from having to undo a connection to test for gas leaks,

I'm interested in doing that. Does anyone have any more details please.

[OldBerkshireBoy]

https://www.peachment.co.uk/wp-content/uploads/2012/12/Calorifiers.pdf

You may find this of use.

Recently fitted a Sigmar marine water heater on mine which is 316 grade s/s, I trusted a boat builder of 30yrs to decide or I`d be flipping a coin.

Re bugs and cracks comments, the hot water will kill bugs and s/s is stronger than copper. If using a vertical tank (household type) then make sure it is sitting on a wooden plinth which allows air circulation underneath as this stops the bases degrading.

[OldBerkshireBoy]

https://www.canalworld.net/forums/index.php?/topic/14557-installing-a-bubble-tester/

https://narrowboatworld.com/10753-do-i-need-a-bubble-tester

Easy enough if you have the room.

[VetChugger]

Dave, maybe you recall quite a kerfuffle was to be had on another forum talking about bubble testers!!

[Smoggy]

40 minutes ago, VetChugger said:

Dave, maybe you recall quite a kerfuffle was to be had on another forum talking about bubble testers!!

Ah the home made bubble tester diagram! Anyone here fancy a homemade bubble tester on their gas system in their boat with sealed hull and a heavier than air fuel? Would go really well with a gas fridge..........

 

[D46]

1 hour ago, Smoggy said:

Ah the home made bubble tester diagram! Anyone here fancy a homemade bubble tester on their gas system in their boat with sealed hull and a heavier than air fuel? Would go really well with a gas fridge..........

 

Mmm like no definitely not I wouldn't trust it it's a gas system after all .

Thing is it's not rocket science to do gas pipe work on r read the BSS guidelines regarding that installation  , BUT for heaven's sake get it checked before using it , sure you can use a bubble tester but a manometer will show up just the same , the good thing about the bubble tester is it's there in place to check in those 4 yrs between the BSC man putting his manometer on the system . 

[Smoggy]

50 minutes ago, D46 said:

Mmm like no definitely not I wouldn't trust it it's a gas system after all .

That was my take on it, I'm all for making something myself if I can save a few quid but not a bubble tester or any other gas fitting.

A manometer on the other hand, no problem......

[ZimbiIV]

What ever you choose get one fitted with an immersion heater in built for the extra cost it is a no brainer.

Even if your marina has good showers, on a cold night it is worth it to save leaving  a nice warm boat to get really cold after a hot shower.

Yes been there done that.

paul

[floydraser]

Well firstly a big thank you for all the worthy contributions, and the frivolous ones!

It's all looking good: I spoke to a highly respected Engineer today (with no reference to the forum) who has a lot of experience of these things and he reflected all the opinions expressed here on the forum. So it's SS for strength and copper for anti bug qualities.

He also mentioned that the trend in hospitals is to replace SS door plates with copper, and some industrial calorifiers are SS with a copper lining.

I only have one mixer tap and I think the thermo link would add a bit of control?

A PO has already fitted an Alde bubble tester next to the gas bottles in the locker, and as soon as I've learned to read in Swedish, I'll be able to use it. What do you mean, “Turn the instruction sheet over.”? Oh yes.

However, an old gas pipe to a previous fridge is capped with a flattened pipe with the end soldered!

My Brother in Law, seen at the helm in one of my videos, is a retired gas fitter and has taught me enough over the years for me to do all my own plumbing. But not gas; it frightens the sh*t out of me. I get Rob to check everything gas; I find water leaks far easier to spot.

Here are the competitors:

https://www.brianwards.co.uk/product/15-litre-calorifier/?highlight=calorifier

https://www.asap-supplies.com/domestic-water-supply/calorifiers-water-heaters-fittings/calorifiers/supa-hotpot-single-coil-calorifier-520115

15 litres big enough? The heater in our touring caravan is 13 litres and we've never found it inadequate.

Floyd.

[OldBerkshireBoy]

Think I would go for around 20- 22 litres, takes around 30-45 minutes to re heat.

[grendel]

dont forget you can get a forum discount at Brian Wards see their advert at the right of the page (quote NBN)

[floydraser]

1 hour ago, grendel said:

dont forget you can get a forum discount at Brian Wards see their advert at the right of the page (quote NBN)

I think I may need it. But the price already shows 15% off, would there be more? I've almost decided to go the copper route anyway, I'll just never let Timothy West helm the boat and it should be OK.

ASAP have some excellent information in the form of videos and pdf's on their website and it looks like I'll need an expansion tank as well. I already have an accumulator. Still, I'm taking swmbo to Cheshire Oaks this weekend so funds should be available after then.

I'll be advertising the gas water heater and a 240 volt fridge around here soon.

[OldBerkshireBoy]

10 hours ago, floydraser said:

I think I may need it. But the price already shows 15% off, would there be more? I've almost decided to go the copper route anyway, I'll just never let Timothy West helm the boat and it should be OK.

I`m afraid it is one or the other not both so it would be the higher 15% discount.

[annv]

Hi Floyd If you fit a larger calorifor it will give you more water storage and if heated by engine more free hot water yes fit a small expansion tank this will stop the pressure release valve opening to relieve pressure when the cold water is heated alternatively pipe it over board or you will get wet bilges you will also need a non return valve in the cold supply to calorifor to stop hot water contaminating the cold and the possibility of legerner in water system . John

[floydraser]

This is interesting:

https://www.asap-supplies.com/hotpot-accumulator-and-expansion-tank-520602

I wasn't expecting the expansion tank to be so pricey. I've seen cheaper ones around but I see differences in the max pressure and operating pressure. I've also seen some marked as being for central heating systems only, with inhibitors added. So am I right in thinking the expansion tank has to be for potable water? And does the operating pressure make a difference?

The blurb for the Hotpot above mentions 12-13psi, isn't that 1 bar ish?

[OldBerkshireBoy]

Just under 1bar (0.9). Put it this way, if it was a kitchen tap then you could stop it with a finger under the tap.

[OldBerkshireBoy]

Looks like mine shown here which will be under furniture eventually. I can check pressure when I am back there tomorrow if it helps. The pump is hidden under the Red pipe.

[D46]

I really don't see the need for the expansion vessel really , after all the tank has a pressure realise valve , that in it's self is of a lower value thant the tanks are tested to .

An accumulator tank however on the cold side really does smooth out the flow and stop's the water pump cycling , pressure should be 2-3 psi less than the pump pressure which different from pump to pump .

1 bar by the way is 14.5 psi .