Carver Cascade 2 hot water tank leak

[barryd]

Just getting round to sorting the van out. Putting water in and testing everything. I had to replace the bung in my old Carver Cascade 2 hot water tank recently as the old one fell to bits when draining down. Filled up, got the water running and the air out of the pipes but then noticed the water was leaking quite quickly out of the new bung area outside. Tightened it a bit but it was still leaking. Undid it and the water squirted out under extreme pressure and I got soaked. I am pretty sure this isnt normal. It normally just trickles out. I had however just filled it and I mistakenly left the pump on when I unscrewed the bung.

It has the black O ring on that it came with but my plan is to try and clean up the area it screws into as its pretty grimy. I am just a bit concerned that there is too much pressure in the tank. There is a pressure release valve in place.

Any thoughts?

 

[GeoffL]

There is a pressure relief valve since it's mentioned in the troubleshooting section of the manual (I had one in a previous caravan and have a scanned copy in PDF format). There's also a fusible plug that might have melted causing water to flow from the cowl. There should be a non-return valve in the pump outlet, so that spurt of water is expected if you didn't release the pressure first by opening some taps.

If it's any help, I've uploaded the manual to my Dropbox and you can download it at https://www.dropbox.com/s/90dhfuxd1dnw4bk/CarverCascade2.pdf?dl=0 HTH

 

[barryd]

There is a pressure relief valve since it's mentioned in the troubleshooting section of the manual (I had one in a previous caravan and have a scanned copy in PDF format). There's also a fusible plug that might have melted causing water to flow from the cowl. There should be a non-return valve in the pump outlet, so that spurt of water is expected if you didn't release the pressure first by opening some taps.

If it's any help, I've uploaded the manual to my Dropbox and you can download it at https://www.dropbox.com/s/90dhfuxd1dnw4bk/CarverCascade2.pdf?dl=0 HTH

Thanks. Ive downloaded the manual. I probably have a paper copy somewhere but as usual I never bother reading the manual. I wonder if normally when I drain it down I do turn the taps to open before then releasing the bung. So maybe this is normal. I shall have a read then go out and see if I can clean it all up and start again.

 

[GeoffL]

Thanks. Ive downloaded the manual. I probably have a paper copy somewhere but as usual I never bother reading the manual. I wonder if normally when I drain it down I do turn the taps to open before then releasing the bung. So maybe this is normal. I shall have a read then go out and see if I can clean it all up and start again.

Regarding excess pressure, I suppose the big question here is whether you have a pressure switch or individually-switched taps. If it's a pressure switch, it should be adjustable but in some installations (like my van) the adjustment screw isn't accessible with the pump bolted down and the pump might need to be temporarily dismounted. AIUI, you should ensure that the pump starts up when a tap is opened and that it shuts down in a reasonable time when the tap is shut. The system pressure might be set too high if the pump continues running for a longish time after the tap is shut. However, that could also be because of an airlock or your system has an expansion tank/plenum that hasn't yet come up to system pressure.

 

[barryd]

Regarding excess pressure, I suppose the big question here is whether you have a pressure switch or individually-switched taps. If it's a pressure switch, it should be adjustable but in some installations (like my van) the adjustment screw isn't accessible with the pump bolted down and the pump might need to be temporarily dismounted. AIUI, you should ensure that the pump starts up when a tap is opened and that it shuts down in a reasonable time when the tap is shut. The system pressure might be set too high if the pump continues running for a longish time after the tap is shut. However, that could also be because of an airlock or your system has an expansion tank/plenum that hasn't yet come up to system pressure.

I am afraid I dont know. Its an old system (1996 Swift Kontiki) however I upgraded from the old internal tank Whale pump which was useless and always failing to a Sureflo pump many years ago. As soon as you turn a tap the pump comes on but yes it does run on a little bit with a kind of groaning noise as it shuts down for a few seconds after you turn a tap off. The Carver hot tank has always leaked a bit through the pressure valve on the outside as occasionally you get a blip from the pump as it comes to life to top up the water thats maybe dripped out the side. Been like that for years. Sometimes if you fiddle with the external pressure valve it will be fine for a day or two.

 

[Pudsey Bear]

Might be worth giving the area where the outside bung lives a really good clean, I had a Carver 2 in my self build and it leaked at the two white plastic joints inside so I stripped the entire thing down cleaned the sockets where stuff screwed in and fitted new parts, no more leaks, I then noticed it leaked gas, fortunately someone sent me a new burner assemble on one of the forums and that was it, they are a really good system,

 

[barryd]

Given the bung hole a good clean (oooeeer Misses) and if anything its worse. Pretty sure I got all the air locks out although it was spluttery at first but probably because I drained the hot tank again yesterday. However tight I tighten the bung its hissing like mad and leaking out. I think its probably time to hand it over to my tame motorhome fixer who is going to look at it next Wednesday when its up for MOT.

In case anyone has any other ideas I made a short video. Please excuse the filthy state of the van. Mrs D will go ape when she sees it. Normally you could eat your dinner off the floor but Ive been in there.

 

[GeoffL]

Just a quick suggestion; but have you also checked that the vent (top left of the outside cover) is air and water tight? That dribble could be coming from there. FWIW, I remember having to replace both O-rings (i.e. the drain and the vent) when the ones on my old caravan perished.

 

[Pudsey Bear]

I'd not worry too much about the pump running on while you have an obvious leak, I'd turn it off until you need it anyway.

Remove the outside winter drain bung and have a good close look at the O ring and see if it has become damaged if so get a new one and be very careful fitting it as they are very soft and easily damaged.

 

[Pudsey Bear]

Here is another Carver manual in case it helps you and others.

Dropbox

www.dropbox.com

Dropbox

www.dropbox.com

Dropbox

www.dropbox.com

Here are some pictures of mine when I was fitting it so you can see what is beyond the polystyrene cover.

And under the cylinder, Hopefully you don't need to go in there as that is not a DIY job.

the burner section under the outer cover.

Dropbox

www.dropbox.com

Dropbox

www.dropbox.com

I'm all out of info and thoughts for now.

 

[barryd]

Thanks guys and for those detailed photos Kev. I am pretty sure its coming from the Drain plug. Its a brand new plug with a new rubber O ring from a caravan supplier on Ebay. The old one disintegrated when I tried to drain down last Nov/Dec. I put a hole right through it so just left it until I came to try and tackle it recently. It was a nightmare to get out and I did it by sawing through the plastic bits with a hacksaw blade. See this thread. https://wildcamping.co.uk/threads/how-to-remove-knackered-drain-plug.90047/

I am now wondering if I maybe damaged the threads with the hacksaw blade and created a route for water to get out but I dont think so. If I have. I wonder if you can just get that part of the housing from a breaker.

 

[Pudsey Bear]

On page 3 of this PDF Barry it looks to be part of the main body.


file:///C:/Users/User/Dropbox/Downloads/From%20Owners/Carver_Cascade2_Instructions.pdf

 

[Pudsey Bear]

Caravan Carver Cascade 2 Gas Only Water Heater Tank / Heat Exchanger DAMAGED | eBay

Find many great new & used options and get the best deals for Caravan Carver Cascade 2 Gas Only Water Heater Tank / Heat Exchanger DAMAGED at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

Caravan Carver Cascade 2 Gas Only Water Heater Tank / Heat Exchanger | eBay

Find many great new & used options and get the best deals for Caravan Carver Cascade 2 Gas Only Water Heater Tank / Heat Exchanger at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

Carver Cascade 2 GE Water Heater 240v/Gas - 5 amp element - caravan / camper van | eBay

Carver Cascade 2 Water Heater 240v/Gas - caravan / camper van. This unit has been striped down, descaled, pressure tested, assembled with all new orings, pressure release valve replaced where necessary, bench tested ready to install.

www.ebay.co.uk

 

[Pudsey Bear]

I think someone makes a replacement version, but forget the name.

 

[barryd]

On page 3 of this PDF Barry it looks to be part of the main body.


file:///C:/Users/User/Dropbox/Downloads/From%20Owners/Carver_Cascade2_Instructions.pdf

That seems to be a link to a file on your hard drive Kev and doesn't work. Looks that way on the photo on the manual posted earlier though.

 

[Pudsey Bear]

Not sure what you do with the hole but...

Whale Rapid Gas & Electric 8 Litre Water Heater Carver Cascade Replacement | eBay

WHALE Rapid Heat Gas & Electric Water Heater. New pressure relief valve with drain function, drains entire water system faster. Robust insulation retains heat for longer. Complete with retro fit kit.

www.ebay.co.uk

 

[barryd]

Caravan Carver Cascade 2 Gas Only Water Heater Tank / Heat Exchanger DAMAGED | eBay

Find many great new & used options and get the best deals for Caravan Carver Cascade 2 Gas Only Water Heater Tank / Heat Exchanger DAMAGED at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

Caravan Carver Cascade 2 Gas Only Water Heater Tank / Heat Exchanger | eBay

Find many great new & used options and get the best deals for Caravan Carver Cascade 2 Gas Only Water Heater Tank / Heat Exchanger at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

Carver Cascade 2 GE Water Heater 240v/Gas - 5 amp element - caravan / camper van | eBay

Carver Cascade 2 Water Heater 240v/Gas - caravan / camper van. This unit has been striped down, descaled, pressure tested, assembled with all new orings, pressure release valve replaced where necessary, bench tested ready to install.

www.ebay.co.uk

I wonder if the first two could be butchered to make a complete unit. Best let my guy take a look at it first though I guess. Perhaps there is a simple way to stop the leak. Could just be a faulty bung for all I know.

 

[Pudsey Bear]

I wish I could have a look at it, but if the worst comes to the thingy at least you know that it can be replaced.

 

[Pudsey Bear]

Carver Cascade Adapter Plate • Fit Malaga in place of Carver Cascade

Used to replace an old Carver Cascade water heater with a Malaga. Needed to enable the Malaga flue to fit into the large hole left by the Carver Cascade.

www.propexleisure.co.uk

Whale Rapid 8 litre Water Heater • Propex Leisure

The Whale Rapid 8L Water Heater gives you extra fast heat up times and the flexibility of versatile gas and/or electric running options.

www.propexleisure.co.uk

 

[Canalsman]

Try some PTFE thread tape on the bung.