Calorifier element

[Blueboat]

Hi, have recently had a lithium set up installed professionally, and was thinking of having a solar dump added for the summer, but as my calorifier is not plumbed into the mains, he could not fit one at the time. Also when he saw the state of the element he said it would need renewing.

When I first bought the boat, I could hear what appeared to be the prv intermittently releasing water, which was cured by turning down the pressure switch on the pump after it failed and I fitted a new one.

Anyway that was a few years ago, and I have had no trouble with it since, but I’m quite clueless about such things, and have taken no notice of it since until now , as I was thinking of getting the dump installed, anyway a local mechanic , looking at the picture, has advised that because of the state of the rust etc, if the element is replaced it may not fit back in, but wouldn’t know obviously till tried.

So my question is, if the element comes out and can’t be threaded back in, does that mean, a new calorifier. How long would that take to source and fit, and would that leave me without water for however long that takes, if the element won’t screw back in. So as a live aboard it would mean moving out till sorted.

Next is it worth taking the time doing that, or just buy a new calorifier. Also as that is gonna cost circa a grand, I have to weigh up if that is worth paying for  with a solar dump on top of that for another few hundred,is it worth it.?

Lastly, the calorifier does look terrible, but working fine, so should it be replaced anyway, ie does it look like it will give me problems soon anyway and best replaced ? How long do they last in this state.

Any advice welcomed.

 

 

[nicknorman]

All we can really see is some sort of deposit on the blue foam insulation and the red plastic cover over the immersion. Not sure where that has come from but perhaps it’s a long term slight leak?

 

Anyway you should take the red plastic cover off the immersion - it’s just held on with that one nut - and see what the actual element etc is like underneath. And try to work out what all that white deposit is!

[Drayke]

Calorifier is made from copper and the flange on top is brass so no rusting, the rust will be the red cover over the electrics on top of the immersion heater so you must have water getting to it from some were. All the white stuff on top looks like lime scale, so again water problems.

If the calorifier need to be replaced the cold feed to it could be caped off , leaving you with cold water only, until a new one is fitted. 

[jonathanA]

Despite what @Drayke says many modern marine cauliflowers are usually stainless steel not copper.  If it is copper then that suggests to me may be a domestic cylinder* and I'm surprised its lasted so long. Off the one picture  it does look like a marine calorifier. The suggestion to cap off the cold water is very sensible and would keep you working. 

 

Worth doing as Nick says and clean it off to see what's going on. Assuming things are reasonably clean under the cover I'd would try the existing immersion before changing it 

 

Eta I've been told copper cauliflowers are a thing 

Edited February 19 by jonathanA
Correction re Cu cauliflowers

[Jen-in-Wellies]

8 minutes ago, jonathanA said:

Despite what @Drayke says proper marine cauliflowers are usually stainless steel not copper.  If it is copper then that suggests to me its a domestic cylinder and I'm surprised its lasted so long. Off the one picture  it does look like a marine calorifier. The suggestion to cap off the cold water is very sensible and would keep you working. 

 

Worth doing as Nick says and clean it off to see what's going on. Assuming things are reasonably clean under the cover I'd would try the existing immersion before changing it 

Plenty of marine cauliflowers made of copper. Got two on my boat. The important thing is having the copper thickness to withstand the higher water pressure. They are significantly more expensive than an equivalent size domestic copper cylinder designed for gravity feed pressure. Copper is expensive stuff. 

[Tony Brooks]

2 minutes ago, jonathanA said:

Despite what @Drayke says proper marine cauliflowers are usually stainless steel not copper.  If it is copper then that suggests to me its a domestic cylinder and I'm surprised its lasted so long. 

 

 

Maybe nowadays, especially if you buy the brand leader, but at least one long term calorifier manufacturer still uses copper as far as I know. The one I fitted to JennyB perhaps 10 years ago was copper. Even some domestic cylinders are stainless steel nowadays, so I don't think the copper - stainless thing holds up.

 

The fact it lasted so long suggests it is a marine calorifier which are made from far thicker copper sheet.

[jonathanA]

@Jen-in-Wellies, @Tony Brooks I stand corrected wasn't aware that copper cauliflowers were still available or were that prevalent. Every day is a school day....

[Jen-in-Wellies]

Just now, jonathanA said:

@Jen-in-Wellies, @Tony Brooks I stand corrected wasn't aware that copper cauliflowers were still available or were that prevalent. Every day is a school day....

It's what I like about this forum. Always learning new stuff. 

[nicknorman]

Surecal marine calorifiers (which are a common narrowboat brand) are copper. I think most are. Stainless tends to be reserved for domestic mains-pressure (unvented) hot water cylinders.

 

Anyway assuming the OP’s is copper, I’ll just mention my experience of having a leak in the immersion heater boss. I removed the IH and replaced the gasket (which is quite a hard fibre thing) but it still leaked. One doesn’t want to put too much tightening force due to the possibility of twisting the cylinder skin (although this can be helped by doing it with the cylinder full of water). But it still leaked. 
 

Then I read/discovered that it’s a good idea to put some PTFE tape on the threads. Not because that makes a seal on the threads, but because it lubricates the threads. Sure enough I could easily turn the heater another 1/4 turn which stopped the leak.

[Sid Charles]

Why not un plug it and take the red cover off, and using one of those brass wire brushes, give it a good scrub, that way you will see what's going on, and as Drayke said it is probably just rust from the cover

[pete.i]

Also remove that pipe insulation and have a look under that. There is green verdidris poking out from under that and that could be where the leak is if there is a leak.

 

[WulfNut]

If you plan it out It shouldn't leave you without water, it may leave you without hot water.  If there isn't a stop tap or shut off valve to isolate it I would make that the first job.  If there is one, I would make testing the stop valve my first job.  

 

Once you are sure you can work on it without being without water, then it's a matter of waiting for the weather to warm up a bit as only having cold water in winter isn't nice ( or safe ) 

 

To be honest with all these modern cooking air fryer and microwave things people have these days you can probably find another way to burn off some extra watts.  

[robtheplod]

Hopefully yours will look better than ours when we did it!  tip for getting it out if it wont budge is run the engine/go for a cruise to make the water hot... this worked for us.....  lucky for you (and us) this is all on the top of the tank as this makes things so much easier!!!

 

Edited February 19 by robtheplod

[IanD]

1 hour ago, Tony Brooks said:

 

Maybe nowadays, especially if you buy the brand leader, but at least one long term calorifier manufacturer still uses copper as far as I know. The one I fitted to JennyB perhaps 10 years ago was copper. Even some domestic cylinders are stainless steel nowadays, so I don't think the copper - stainless thing holds up.

 

The fact it lasted so long suggests it is a marine calorifier which are made from far thicker copper sheet.

I had one made by coppercylinder.co.uk (clue is in the name) with extra-high-yield coils (5kW each) for both CH boiler and generator, plus a 2kW immersion for solar dump. Cost a fortune but heats up much more quickly than the standard Surecal ones, Dave Jesse measured these at just over 1kW per coil so they take a long time to heat up a tank from cold to hot.

[ditchcrawler]

4 hours ago, robtheplod said:

Hopefully yours will look better than ours when we did it!  tip for getting it out if it wont budge is run the engine/go for a cruise to make the water hot... this worked for us.....  lucky for you (and us) this is all on the top of the tank as this makes things so much easier!!!

 

But that shows where the rust type stains can come from

 

[matty40s]

Under the cap..

 

what it should look like

Just replacing my mums thermostat as plumber who fitted new one last year used very thin cable and it has burnt through the thermostat top end, eventually tripping everything. He has now retired so the guarantee is worthless.

 

Edited February 19 by matty40s

[BEngo]

If removing the whole immersion, use a proper hex rinb spanner or tube spanner and do it with water in the cauliflower, but not under pressure.  Apply pressure evenly and once you have the thing turning drain the water out and then remove it.  The water will  support the skin of the cylinder and resists crinkling.  Fill the cauliflower with water as far as practicable before refitting. Apply some Hylomar to the fibre ring gasket.  Use a new one.

[ditchcrawler]

45 minutes ago, BEngo said:

If removing the whole immersion, use a proper hex rinb spanner or tube spanner and do it with water in the cauliflower, but not under pressure.  Apply pressure evenly and once you have the thing turning drain the water out and then remove it.  The water will  support the skin of the cylinder and resists crinkling.  Fill the cauliflower with water as far as practicable before refitting. Apply some Hylomar to the fibre ring gasket.  Use a new one.

That is exactly how I would do it. I prefer the box spanner as you can put even pressure on it. I have always used Bosswhite 

[BEngo]

 Ah the smell of Bosswhite!  Wonderful sealing stuff on big threads, esp. with hemp, but it does tend to go rather hard and be recalcitrant about coming undone after9o a while

[ditchcrawler]

32 minutes ago, BEngo said:

 Ah the smell of Bosswhite!  Wonderful sealing stuff on big threads, esp. with hemp, but it does tend to go rather hard and be recalcitrant about coming undone after9o a while

Very true

[Sid Charles]

Slight variation on the same subject, the boat I have been restoring came with a Cauliflower, it was full of water and difficult to move, I drained most of the water and discovered things which I was unaware of such as the non return valve, I replaced the (forgot the term for it) the brass valve on the top and I tested the element which appears OK, I have plumbed the Cauliflower in and it is where I intend to have it on the boat, which is stood upright in the corner near the engine. Oh and it is piped up to the engine. My concern is getting water back into it, I am on dry land and no easy way of filling my water tank under the bow of the boat, but I need to fill the Cauliflower surely ? do you think it would be sensible to get water into my water tank and let the pump send it down to the Cauliflower, and what stops it when it is full ?

[Jen-in-Wellies]

7 minutes ago, Sid Charles said:

Slight variation on the same subject, the boat I have been restoring came with a Cauliflower, it was full of water and difficult to move, I drained most of the water and discovered things which I was unaware of such as the non return valve, I replaced the (forgot the term for it) the brass valve on the top and I tested the element which appears OK, I have plumbed the Cauliflower in and it is where I intend to have it on the boat, which is stood upright in the corner near the engine. Oh and it is piped up to the engine. My concern is getting water back into it, I am on dry land and no easy way of filling my water tank under the bow of the boat, but I need to fill the Cauliflower surely ? do you think it would be sensible to get water into my water tank and let the pump send it down to the Cauliflower, and what stops it when it is full ?

Cauliflowers sit horizontal, or upright by design. The position of the various inlet and outlet ports depend on how it should be mounted. Was your cauliflower originally vertically mounted? 

To fill the cauliflower, get water in to the main wster tank. Switch on the pump and open a hot tap. The cauliflower will then fill itself. When full, water will come out of the hot tap. Close the tap and the pump will switch itself off. This assumes the hot water take off is at the top of the cauliflower. See what I said above about cauliflower design. For a vertical cauliflower, cold water in should be near the bottom. Hot water out, at the top. Pressure relief valve near the top. Engine coolant circulation in and out towards the bottom. 

[Tony Brooks]

3 minutes ago, Sid Charles said:

but I need to fill the Cauliflower surely ?

 

Why? Although any water in it will help support the heating coils and possibly damp any vibration, experience suggests this is not an issue, so I would suggest that you do not need to fill the calorifier until you are ready to fully test the domestic water system. At that point you will have to fill the tank.

 

Engine coolant and central heating liquid is kept totally separate from the domestic water inside the calorifier.

 

8 minutes ago, Sid Charles said:

do you think it would be sensible to get water into my water tank and let the pump send it down to the Cauliflower, and what stops it when it is full ?

 

The domestic water pump has a pressure switch on it, so when the system is full, with all outlets turned off, the pump automatically stops. Otherwise you can just turn the water pump off so it stops pumping.

[Sid Charles]

Thanks for that, and yes it is stood upright, I understand the turn the hot water tap on that makes semse, thanks I wasn't thinking properly as usual I forgot that the water pump will turn off.