I need to replace my immersion heater element 2moro,it's a 27inch fitting to the top of the HW cylinder.
Can I get away with just partially draining the HW cylinder to a level where when I unscrew the old element out water won't flow out?or should I drain it down completely?
Is the best way to drain it to run a hose from the drain plug to the bath?I don't have a drain tap so will a spanner do?should I WD40 it first?
HW cylinder size is 900x450mm & i think it stores 117 litres any ideas for the length of time to give it to drain?
Any tips much appreciated
thanks in advance

On Thu, 15 Feb 2007 17:39:03 +0000, kjhi98
mused:


I need to replace my immersion heater element 2moro,it's a 27inch
fitting to the top of the HW cylinder.

Right.

Can I get away with just partially draining the HW cylinder to a level
where when I unscrew the old element out water won't flow out?or should
I drain it down completely?

Generally I just drain down until I can remove the element without
getting wet, no need to drain it right down.

Is the best way to drain it to run a hose from the drain plug to the
bath?

As long as the edge of the bath is below the level at which you want
the tank draining to.

I find the easiest way to drain down is turn off the cold supply to
the cylinder, open a downstairs hot tap, open an upstairs hot tap and
then just drain off a few litres via the drain off once the hot taps
have stopped running.

I don't have a drain tap so will a spanner do?

Yes.

should I WD40 it first?

No, although some of the cheaper drain offs have a rubber inside that
stays put as you unscrew it. This involves you stripping it down and
prodding the washer with a screwdriver, while it is full of water.

HW cylinder size is 900x450mm & i think it stores 117 litres any ideas
for the length of time to give it to drain?

Few minutes to drain it to the level you want.
--
Regards,
Stuart.

On Thu, 15 Feb 2007 22:40:10 +0000, Lurch wrote:

On Thu, 15 Feb 2007 17:39:03 +0000, kjhi98
mused:


I need to replace my immersion heater element 2moro,it's a 27inch
fitting to the top of the HW cylinder.

Right.

Can I get away with just partially draining the HW cylinder to a level
where when I unscrew the old element out water won't flow out?or should
I drain it down completely?

Generally I just drain down until I can remove the element without
getting wet, no need to drain it right down.

Is the best way to drain it to run a hose from the drain plug to the
bath?

As long as the edge of the bath is below the level at which you want
the tank draining to.

I find the easiest way to drain down is turn off the cold supply to
the cylinder, open a downstairs hot tap, open an upstairs hot tap and
then just drain off a few litres via the drain off once the hot taps
have stopped running.

I don't have a drain tap so will a spanner do?

Yes.

... some ... drain offs have a rubber inside that
stays put as you unscrew it. This involves you stripping it down and
prodding the washer with a screwdriver, while it is full of water.

Actually the washer disintegrates and comes of the little tit (technical
term) on the bit you're unscrewing and stays in the valve body. If it
doesn't want to open don't prod it unless you can cope with it starting
and not stopping because the washer's fallen to pieces! Better to loosen
the immersion heater and either j-cloth or wet-vac away the dribble as it
starts until you've got the level down.

On Fri, 16 Feb 2007 00:18:02 GMT, John Stumbles
mused:

... some ... drain offs have a rubber inside that
stays put as you unscrew it. This involves you stripping it down and
prodding the washer with a screwdriver, while it is full of water.

Actually the washer disintegrates and comes of the little tit (technical
term) on the bit you're unscrewing and stays in the valve body.

I was struggling with the technical terms there, thanks for filling in
the gaps!

If it
doesn't want to open don't prod it unless you can cope with it starting
and not stopping because the washer's fallen to pieces! Better to loosen
the immersion heater and either j-cloth or wet-vac away the dribble as it
starts until you've got the level down.

Yes, removing the washer with a screwdriver has much the same effect
as just jigsawing through the pipe.

The other way to d it is to drill a small hole in the pipe and have at
least 2 small bowls, 2 buckets, towels and dustsheets and someone to
empty the buckets on hand.

Or, those cheap 'screw on' washing machine valves that pierce the
copper pipe, use one of those to drain the system down.

If the drain off is faulty then while the system is empty replace it.
--
Regards,
Stuart.

"kjhi98" wrote
Can I get away with just partially draining the HW cylinder to a level
where when I unscrew the old element out water won't flow out?or should
I drain it down completely?

Don't drain it further than necessary as the water in the tank gives it
weight and stability!
When I posed a similar question (actually concerning the fitting of an essex
flange - don't even go there!) I was advised to budget time for replacing
the cylinder should the whole job go tits up. Provided the cylinder is in
good nick, it hopefully won't come to that though.

Phil

"Lurch" wrote

Or, those cheap 'screw on' washing machine valves that pierce the
copper pipe, use one of those to drain the system down.


Now that is an idea worth remembering!
My drain cock is decidedly dodgy.

Phil

On Fri, 16 Feb 2007 09:17:46 +0000, me9 wrote:

I would remove the connection to the top (dome) of the tank, and shove a
hose down it and syphonit out , about a bucketfull will be enough. First
turn of the cold fill, and drain the hot taps, then when you disconnect
the top pipe you'll only get a small quantity to mop up. A towel or two
will do to collect the drips.

IME you'll be lucky to get the top connection off the cylinder, but you
can probably j-cloth/wet-vac away enough from the immersion boss as you
unscrew it to get that off and syphon out from there.

If you have a wet vac and you're in a hard water area you can hoover out
some of the half ton of scale you've probably got in the cylinder while
you're at it.

And yes do replace the drain-off-cock washer while you've got the cylinder
empty.