Stuck immersion heater bung

[RobertMP]

Been struggling with this for far too long today! Sorted now.

New boiler being fitted next week (like for like conventional but hopefully cheaper on the gas!) so no hot water for a couple of days... unless I fit an immersion heater to the indirect cylinder. Easy job... just unscrew the plug bunging the hole and screw an immersion heater in its place.

I tried a big stilson - I could see the cylinder flexing.

I tried a cold chisel to knock the edge flange round - nothing.

I tried a blowlamp on the bung to heat it up and hopefully break the seal - still no movement.

So its give up the idea or go for broke

Battery drill, cheapy dremel type thing and hacksaw blade in a padsaw handle time.

Cut as much into the thread as I dared then wiggled the lump with a mole wrench until it cracked out. I'd imagined that having got a bit out it still might not move and I'd have to cut in in half.. fortunately the stilsons shifted it

Quick clean up and ready for the immersion to go in.

Peering down the hole the indirect coil looks reasonably clean for a 20+ year old cylinder. Not worried about a few brass shavings ending up in the bottom of the cylinder.

Immersion is wired to a long cable and a plugtop with 13A fuse. Only going to be used for a short while so don't want it permanently connected.

Phew. Cup of tea time now

 

[Dibs-h]

Was it a proper plumber's torch or a just a DIYer's blowlamp? I used to use the latter, but having a got a Plumber's torch now and started using MAPP gas - made me wonder why I'd never used them before.

 

[Oldman]

Well done!

Lucky it was a 20+ yr old cylinder. I think a modern one would have parted company at the neck long before your efforts would have got the flange nut off.
Pretty thin these days I believe due to copper prices.

 

[RobertMP]

Standard blowlamp. Did consider buying mapp gas kit but with no guarantee that would work either I went to plan B

 

[Paul Chapman]

These 5 minute jobs :lol:

Always useful to have an immersion heater for those occasions when the boiler packs up (usually at 11pm on Christmas Eve).

Cheers :wink:

Paul

 

[dickm]

Lucky it was a 20+ yr old cylinder. I think a modern one would have parted company at the neck long before your efforts would have got the flange nut off.
Pretty thin these days I believe due to copper prices.

A long time ago I removed the old direct cylinder from our then house to replace it with a modern indirect one, and got more for the old one as scrap than the cost of the new one! It was about 2mm thick copper.
All together now - those were the days

 

[Jenx]

Heat is the way to go... but lots of it.
Their usually 'boss-white'd' in, or worse still, sometimes with Stag ..and often with hemp in addition to that too.
And its a big copper 'conductor' thats delighted to dissipate the heat away as almost as quickly as you can put it in... so you have to 'hud the beastie at it', with a relatively big flame.

I'd advise if you're ever faced with doing it again, keep the stillsons away from it, as the brass is relatively soft, and any 'rough-jaw'd' implimpent like a stillie, or big footprints or water pump pliers will tend to tear hell out of the brass, and usually shortly after that, your hands.

A big flat-jaw'd shifter is always preferrable on a hex of any description, if possible..

A short immersion spanner is ideal, either with a half decent length of steel tube over the short handle, or you can give it a decent clout with a lump hammer whilst the heat is on ( takes two if possible to do this ).
Once you've cracked the 'hold' the jointing compound has, she'll pop out easy enough.
Don't panic about the flex in the cylinder, even if you were unlicky enough to put a bit of a dent in it, it wont affect the performance of it in any way.. other than making insertion of a new immersion possibly a bit trickier.

Faulty Immersions : meter the 'stat out to check it first .... the actual element is only a coil surrounded by refactory cement, encased in a copper sleeve, and they generally don't fail very often...

For the benefit of anyone else ever coming across having to replace one, remember to get the correct length of heater.. once in operation the water BELOW the bottom of the element doesn't heat much, so if you were to pop an 11" heater into a 42" High cylineder.. you'll get a sink full of hot water and precious little else. ... ( have seen this done once by someone making a galliant effort to 'fix' his HW Problem.. and despite his best efforts, he was perplexed when he couldn't get a cylinder-full of HW for his bath )

But well done... many are put off by the thought of such jobs... and you've pulled it off perfect ! nice one !

 

[RobertMP]

I bought an immersion box spanner thing along with the immersion. Bit disappointed the hex on the bung was a different size! Thought I was going to have something the right size to get it off with.

I could see colour change from the heat on the bung. Also had the foam insulation to think about. had wet cloth on it but it wasn't staying wet for long

 

[Jenx]

The spanner would be handy for fitting the new fella though !

Mind you... still a heck of a lot easier than cutting in the old 6 bolt versions with a Monodex etc.... not easy and you only get the one shot at it !

Nice one, Robert

 

[Night Train]

I still have my special tools for immersions from my electrician days.

I used good quality box spanners and welded onto it a 3/4" drive socket and used 3/4" drive extensions, U joints and T bars. It made shocking and shifting elements and plugs really easy even when access was bad.

 

[Derek Willis.]

Removed many a stuck plug or heater, always use a proper spanner, and if it doesn't budge apply heat, it never fails.
derek.