Carver Cascade 2 water heater tie rod break.

[Spriddler]

At 6 a.m. yesterday I switched on the water heater then hopped back into bed with a brew. 20 mins later a mighty thump shook the body, the pump started running and water began to run out from under the Carver heater locker.
In short the steel tie rod (Item 23) holding the whole heater assembly together had broken at where the threaded end enters the alloy heat exchanger casting.
It should be like this:

However, on disassembly I found that the tie rod had snapped due to corrosion at the threaded end and the end was stuck flush with the heat exchanger casting:

The casting with the broken end (photo above) is currently soaking in releasing fluid before I attempt to remove it using an 'EasyOut' drill bit. I'm not keen to try heat as the casting is probably the cheap 'n nasty reclaimed alloy from washing machines or whatever.
A plate on the Carver unit identifies it as from 1994 so it hasn't done too badly. The unit itself is obsolete although following my eBay search it appears that the tie rod is still available at £35.
A Propex Malaga E5 is said to be a direct and complete replacement for the Carver but at £462 I'd rather restore the Carver.
Keeping everything crossed that I'll be able to extract the broken bit and reassemble with a new tie rod.

 

[Rob and Val]

Hope everything goes O.K. We've also got a 1994 Carver unit.

 

[chaser]

Where are you mate, might have one in the shed. But can't be sure till we get home.
It's yours if I can find it.

 

[Jev88]

Cost of new old stock Carver. £500
Cost of Propex Málaga with bigger capacity, faster heat and more efficiency. £500

It isn't quite a straight swop but close enough. I had to raise exhaust end an inch to match existing exit hole.

MCEA local engineer can still buy new old stock of refurb the old Carvers.

 

[Spriddler]

Where are you mate, might have one in the shed. But can't be sure till we get home.
It's yours if I can find it.

That's a great offer chaser and I'll update my progress with removing the broken bit, but if you do have one kicking about I'll be very happy to provide some virus-free Bank of England wine tokens in exchange.
You're 200 mls North of me but I've an outstanding date (that's 'outstanding' as in overdue rather than as in amazing ) with an old Grab-a-Granny friend (that's 'old' as in both long term and elderly ) in 'Uddersfield so could detour to Uttoxeter no prob.
More anon...........

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[Spriddler]

Cost of new old stock Carver. £500
Cost of Propex Málaga with bigger capacity, faster heat and more efficiency. £500

It isn't quite a straight swop but close enough. I had to raise exhaust end an inch to match existing exit hole.

MCEA local engineer can still buy new old stock of refurb the old Carvers.

Yep, thanks. As I mentioned earlier the Malaga is an option although I've been very satisfied with the Carver and provided that I can remove the broken bit or get another heat exchanger casting it should see me out.
I've enjoyed fixing/restoring stuff for the past 55 years; mostly classic MG's and vintage British motorbikes and have a fully equipped workshop (lathe, milling machine, TIG and gas welding kit etc. etc.) to play in so it'll amuse me.
I've seen ads for refurbed Carvers in my research but I'm a bit circumspect about 'refurb' quality so I'd rather refurb mine myself to a known standard.
Although for the past ten years I've had to work one-armed (biking crash) I can still ride my m/bikes and maintain the m/h; fitting a Gaslow system and overhauling the diesel injector pump to name but two satisfying jobs so you can see I'm a glutton for a challenge.

 

[Jev88]

Yep, thanks. As I mentioned earlier the Malaga is an option although I've been very satisfied with the Carver and provided that I can remove the broken bit or get another heat exchanger casting it should see me out.
I've enjoyed fixing/restoring stuff for the past 55 years; mostly classic MG's and vintage British motorbikes and have a fully equipped workshop (lathe, milling machine, TIG and gas welding kit etc. etc.) to play in so it'll amuse me.
I've seen ads for refurbed Carvers in my research but I'm a bit circumspect about 'refurb' quality so I'd rather refurb mine myself to a known standard.
Although for the past ten years I've had to work one-armed (biking crash) I can still ride my m/bikes and maintain the m/h; fitting a Gaslow system and overhauling the diesel injector pump to name but two satisfying jobs so you can see I'm a glutton for a challenge.

I think it is always advised to replace drain valve and other connections as they age, brittle and snap so if you have the unit in bits do these too.

 

[PeteH]

What is the Tie rod Material?. Just interested, as some metals react with salts in the water to accelerate corrosion.

 

[gus-lopez]

Once you have the broken part out why not make the new tie rod out of stainless steel ?

 

[Googlebot]

I think it is always advised to replace drain valve and other connections as they age, brittle and snap so if you have the unit in bits do these too.

I wouldn’t, having took one apart you touch them and they snap, take an age to get out and clean and then you have to replace. If they work, and don’t leak then leave well alone.

Don’t ask me how I know a standard tow bar bolt fits the drain thread....

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[Spriddler]

I think it is always advised to replace drain valve and other connections as they age, brittle and snap so if you have the unit in bits do these too.

Funny you should mention that. You evidently know your Carvers!!
Just last year I had a leak at the Carver hot water outlet and it was brittle, snapping off when trying to remove it. I removed the stub from the boiler by drilling it away then getting the remains out with a thread pick to fit a new outlet.
There was a lot of dusty corrosion in the alloy casting but enough thread remained to be able to run a tap through to reclaim it.

 

[Spriddler]

What is the Tie rod Material?. Just interested, as some metals react with salts in the water to accelerate corrosion.

Galvanised steel apparently. Not ideal materials together with (prob poor quality) aluminium alloy due to galvanic reaction but the old one did last 25 years. It's possible that someone has used an inappropriate sterilising medium.

Once you have the broken part out why not make the new tie rod out of stainless steel ?

I have been considering that as I think I have some 12mm s/s bar and can cut the thread at each end....., that's if I can remove the broken bit from the casting. Not rushing the attempt as it's soaking in releasing fluid and patience (and ongoing musing over a brew or two) is the key. I won't try flame heating as the alloy would probably disintegrate/crumble (been there on other alloy castings). As a last resort I might try with a hot air gun.

 

[Spriddler]

Update...........
chaser You can come out from rummaging through your shed now.
I managed to extract the broken off piece and the internal thread is good so I ordered a new tie rod and seal kit, expected tomorrow, so it should be fully refurbed, reassembled and up and running by the weekend.

 

[chaser]

Update...........
chaser You can come out from rummaging through your shed now.
I managed to extract the broken off piece and the internal thread is good so I ordered a new tie rod and seal kit, expected tomorrow, so it should be fully refurbed, reassembled and up and running by the weekend.

You will never believe this I just saw your post on the lost gas cover and thought bloody hell I said he could have the tie bar, been out to the shed and found it, and was just going to message you that I had found it. And there you are.unbelievable.

 

[Spriddler]

You will never believe this I just saw your post on the lost gas cover and thought bloody hell I said he could have the tie bar, been out to the shed and found it, and was just going to message you that I had found it. And there you are.unbelievable.

Much appreciated chaser but it always good to have a reason to spend time in the manshed, hopefully mine'll arrive tomorrow.
I was going to make a tie rod from s/steel but it needs what appears to be an anodised or ceramic coating so I paid £49 for a new one with a couple of tuppeny 'O' rings. Tie rod breakage seems to be a fairly common failure with these old Cascade heaters so you could put yours on eBay...........
A far better result than having to spend nearly 500 squids on a Propex Malaga replacement heater.

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[68c]

This is a known fault with these heaters. It is recommended to inspect and/or replace it. Parts about £50 on Ebay.

 

[Spriddler]

Just to wrap up the saga.
New tie rod fitted and heater reinstalled and working perfectly on 240v and gas and no water leak after 3 weeks.
£49 for the tie rod (eBay) saved me replacing the entire (now obsolete) heater at £462 so by now I think I can safely treat myself to an ice cream.

 

[united-contacts]

At 6 a.m. yesterday I switched on the water heater then hopped back into bed with a brew. 20 mins later a mighty thump shook the body, the pump started running and water began to run out from under the Carver heater locker.
In short the steel tie rod (Item 23) holding the whole heater assembly together had broken at where the threaded end enters the alloy heat exchanger casting.
It should be like this:
View attachment 408100


View attachment 408103
However, on disassembly I found that the tie rod had snapped due to corrosion at the threaded end and the end was stuck flush with the heat exchanger casting:

View attachment 408101

View attachment 408102


The casting with the broken end (photo above) is currently soaking in releasing fluid before I attempt to remove it using an 'EasyOut' drill bit. I'm not keen to try heat as the casting is probably the cheap 'n nasty reclaimed alloy from washing machines or whatever.
A plate on the Carver unit identifies it as from 1994 so it hasn't done too badly. The unit itself is obsolete although following my eBay search it appears that the tie rod is still available at £35.
A Propex Malaga E5 is said to be a direct and complete replacement for the Carver but at £462 I'd rather restore the Carver.
Keeping everything crossed that I'll be able to extract the broken bit and reassemble with a new tie rod.

I've bought a tgread tie bar from b&q 4pounds, painted with heat resistant paint, hope it will work