Surecal Calorifier Leak

[Zosima]

Hi all, many thanks in advance for anyone who can advise us.

 

We've been living aboard for just over six months now and are currently experiencing our first hiccup. We're having problems with our Surecal calorifier. Ten or so days ago it started tripping the shoreline power, and not knowing the first thing about boilers/calorifiers, I tried to get someone in to take a look. No one could make it before Christmas, so I ended up speaking to Surejust (manufacturer) who advised it was almost certainly a broken immersion element. We duly ordered a new one, installed it ourselves, and to our delight it worked.

 

Returning to the boat after a couple of days away, however, we found that exactly the same thing had happened - it had tripped the power, and there was no hot water. I noticed that water was eking its way out at the top, around the connections, and in retrospect it seems stupid we didn't take note of this happening before (though I now remember it was - I think we were just too keen to write it off as part of the Surejust guy's explanation). When I took the immersion element out the second time, the connections were submerged in water. I dried it out, put it back in and it worked.

 

SO we have concluded that the reason it is tripping out the power is the water leaking out of the top, and therefore because it was inadequately sealed. We're planning on sealing it properly asap, but my question is - is there anything we've overlooked? Could it be something to do with water pressure (and what do you do about that?) I can't stress enough how little knowledge we have in this area so any suggestions are appreciated.

 

Thanks and Merry Christmas.

 

tl:dr - water's coming out of the top of the calorifier, is it just bad sealant?

[Robbo]

If you don't have an expansion tank, get one, but check the PRV as well.

[Robbo]

 

tl:dr - water's coming out of the top of the calorifier, is it just bad sealant?

 

It's not the PRV (Pressure Release Valve) is it? They should be a hose from it to either outside, or to a tray. This valve releases the pressure when the heat builds up and is "normal" to do so if you don't have a expansion tank.

Edited December 23, 2014 by Robbo

[Zosima]

Thank you Robbo (I have already actually tried to reply to you twice but the forum hasn't let me...) We don't have an expansion tank, will look into that. When I put the element back in I will also have a look at the PRV.

[Phil Ambrose]

Trying to remember, last time ,I fitted a immersion heater it was sealed with a round flat seal, bit like a big rubber washer. Agree with the comments about expansion vessel and the PRV.

Phil

[ditchcrawler]

I can't work out where the OP is saying the water is coming from. If it is entering the head of the immersion heater round the actual element. ie. The two little rods that come through the boss with the terminals on them then the immersion is faulty. Or is it coming round the threads of the boss and trickling into the head?

[ditchcrawler]

Which point is leaking please

[alan_fincher]

Which point is leaking please

 

Perhaps it is not leaking at all, and is actually coming from that spray can to the left.

 

(Coat, please!).

[Zosima]

Thanks for the responses. Fairly sure the leak is coming round the threads of the boss. Does that help?

[Phoenix_V]

Thanks for the responses. Fairly sure the leak is coming round the threads of the boss. Does that help?

We had this, I think it started when I turned the thermostat up to max by mistake, worried we had broken something but unscrewed the boss and resealed with fernox lsx leak sealer (screwfix) the gasket was not enough, it is important to leave a few hours to set before refilling and using - dont ask me how i know this!

 

Do check the prv too though

[valrene9600]

If the water is coming through the threads then it needs some selant to bed it in . If the reason it is leaking even with a good seal is pressure then my first try would be to turn the PRV a few times to make sure it works and is not causing the pressure that`s forcing the water through the threads as the water heats up.

To be sure fitting a new PRV(any decent plumbers) will eliminate that side of things.

Not sure of the settings on the element but have got it set to a high setting that is to high for this type of tank.

Just my thoughts, hope it helps.

Keep checking everything people suggest and regularly update what you have tried etc and the good people will keep helping you along to a fix.

After thought: has the element been overtightened and distorted the cylinder enough to allow a leak past the gasket?

[MtB]

Yes if it's coming from the thread, you haven't tightened it enough! Not sure how it is getting from there up into the top of the immersion heater though.

 

Immersion heaters come with a fibre sealing washer. This is rarely watertight unless to do the thing up seriously tight, or put silicone sealant on both faces of the washer.

 

I suggest you carefully dry everything with tissues then carefully inspect with a bright torch and your reading glasses ON and find precisely where the water is emerging. Only then can you begin to consider how to stop it.

 

MtB

[valrene9600]

Just been looking at images of a surcal element and can`t see how the water would emerge from the threads and come up the side and flood the elements electrical connections.

Unless, is your tank upright or laying down? Laying down would allow water to run into the electrics and short it out.

Come on OP talk to us.

have you checked the cable under the clamp. Is it in good condition and not burnt through causing a short.

[MtB]

Just been looking at images of a surcal element and can`t see how the water would emerge from the threads and come up the side and flood the elements electrical connections.

Unless, is your tank upright or laying down? Laying down would allow water to run into the electrics and short it out.

Come on OP talk to us.

 

The correct answer is, of course, it can't. So either the OP has two leaks, or there is something really odd going on we haven't grasped.

 

MtB

[Zosima]

Folks. Sorry not to do your advice justice yet but I'm away from the boat for a couple of days. Will get my reading glasses on when we do get back! Thanks all.

[Phoenix_V]

Just been looking at images of a surcal element and can`t see how the water would emerge from the threads and come up the side and flood the elements electrical connections.

Unless, is your tank upright or laying down? Laying down would allow water to run into the electrics and short it out.

Come on OP talk to us.

have you checked the cable under the clamp. Is it in good condition and not burnt through causing a short.

If it is foam insulated as most are a leak from anywhere will form a pond over the electrics water held there by the insulation (cure cut away channel in insulation to allow water to escape)

[MtB]

And I doubt the OP wants to hear this, but as I never tire of saying on here, calorifiers fitted with no expansion vessel eventually split and leak from metal fatigue.

 

Here we have yet another case of this, I suspect.

 

 

MtB

[Neil Smith]

Mike,

 

How big should the expansion tank be for a 50 litre cal.

 

Thanks Neil

[Zosima]

And I doubt the OP wants to hear this, but as I never tire of saying on here, calorifiers fitted with no expansion vessel eventually split and leak from metal fatigue.

 

Here we have yet another case of this, I suspect.

 

 

MtB

All I want to hear is "we have hot water" so I'm willing to entertain any possibility as long as it results in us getting it sorted! Thanks for bringing it up.

[MtB]

Mike,

 

How big should the expansion tank be for a 50 litre cal.

 

Thanks Neil

 

 

Whatever the calorifier manual says, and they always specify one. Or at least all the calorifier manuals I have ever seen do.

 

Size denends on whether there is a non-return valve in the cold feed connection in it (in which case two are needed), but typically about three or four litres. The bigger the better though.

 

MtB

 

MtB

[DJW]

If it is foam insulated as most are a leak from anywhere will form a pond over the electrics water held there by the insulation (cure cut away channel in insulation to allow water to escape)

 

This is exactly what happened with ours. It was leaking around the threads of the immersion boss and the water pooled sufficiently to swamp the electrical connections.

 

I replaced the immersion (electrics were knackered from being underwater) and sealed a new one in with Fernox LSX as above. I also fitted a 5l expansion vessel and (touches wood) it's been fine since.

[Zosima]

Hi all, thanks very much for bearing with us. We've sealed the immersion element's thread with PTFE tape, left it for an hour or two as per advice above, and as yet there doesn't seem to be any leak. The water is heating up, so without wanting to curse it, so far so good.

 

While we don't have an expansion tank, the PRV connects to a hose which leads outside, and that let out a bit of water when we got things running again. Does this hose negate the need for an expansion tank, or would it be advisable anyway?

[ditchcrawler]

I would suggest you have one as well as the PRV going overboard

[MtB]

While we don't have an expansion tank, the PRV connects to a hose which leads outside, and that let out a bit of water when we got things running again. Does this hose negate the need for an expansion tank, or would it be advisable anyway?

 

Absolutely not. The expansion vessel reduces the number of high/low pressure cycles on the cauliflower by about a factor of ten, thus increasing it's life by a factor of ten.

 

Your call. How often do you want to replace your calorifier?

 

MtB

[dor]

We had this, I think it started when I turned the thermostat up to max by mistake, worried we had broken something but unscrewed the boss and resealed with fernox lsx leak sealer (screwfix) the gasket was not enough, it is important to leave a few hours to set before refilling and using - dont ask me how i know this!

 

Do check the prv too though

 

Spent ages on my last boat trying to get the immersion heater boss to seal properly on a new calorifier. Fernox LS-X sealant was the final solution (and good for a number of other things as well). This was after failing with ordinary silicone sealant. I am never without a tube at home or on the boat now.