All,
I am on Domestic 10 elec and so my immersion tank heats the water
overnight. Yesterday I noticed that the water was cold after only a
small amount had been used, I checked the fuses etc and evrything seemed
OK. So, I put it down to using a little more than we thought and hoped
it would be hot again this morning - its not !
So, how do I go about testing the element to see if its dead ?? I am
competant with a DMM but what I am wondering is how these things
normally show they are dead - will earth short to neutral / live, will
the live/neutral resistance go up to infinity ?? If I can do this simple
test myself I can call my electrician I *know* whats wrong rather than
ask him out it tun out to be something else (like what ?!?!).

Thanks in advance,
N.

"NC" wrote in message news:3JT4c.187$N1.178@newsfe1-win...
All,
I am on Domestic 10 elec and so my immersion tank heats the water
overnight. Yesterday I noticed that the water was cold after only a
small amount had been used, I checked the fuses etc and evrything seemed
OK. So, I put it down to using a little more than we thought and hoped
it would be hot again this morning - its not !
So, how do I go about testing the element to see if its dead ?? I am
competant with a DMM but what I am wondering is how these things
normally show they are dead - will earth short to neutral / live, will
the live/neutral resistance go up to infinity ?? If I can do this simple
test myself I can call my electrician I *know* whats wrong rather than
ask him out it tun out to be something else (like what ?!?!).

Thanks in advance,
N.

Elements are very cheap and fail regularly in hard water areas. If live was
shorted to earth the fuse would blow. Quite often a small amount of current
will flow through the element, so a resistance test will only help if you
first work out what the resistance should be, in your case you are looking
for about twenty ohms across the element. If your figure is a long way up
from this, then the element has failed. Turn the water off, disconnect
wiring, unscrew and reverse the process to install a new one. Often not as
easy as it sounds.

MrCheerful

MrCheerful wrote:
"NC" wrote in message news:3JT4c.187$N1.178@newsfe1-win...

All,
I am on Domestic 10 elec and so my immersion tank heats the water
overnight. Yesterday I noticed that the water was cold after only a
small amount had been used, I checked the fuses etc and evrything seemed
OK. So, I put it down to using a little more than we thought and hoped
it would be hot again this morning - its not !
So, how do I go about testing the element to see if its dead ?? I am
competant with a DMM but what I am wondering is how these things
normally show they are dead - will earth short to neutral / live, will
the live/neutral resistance go up to infinity ?? If I can do this simple
test myself I can call my electrician I *know* whats wrong rather than
ask him out it tun out to be something else (like what ?!?!).

Thanks in advance,
N.


Elements are very cheap and fail regularly in hard water areas. If live was
shorted to earth the fuse would blow. Quite often a small amount of current
will flow through the element, so a resistance test will only help if you
first work out what the resistance should be, in your case you are looking
for about twenty ohms across the element. If your figure is a long way up
from this, then the element has failed. Turn the water off, disconnect
wiring, unscrew and reverse the process to install a new one. Often not as
easy as it sounds.

MrCheerful



Thanks - confirms my thoughts - l/n resistance is in the region of
Mega/Kilo ohms! Just my luck - rented a flat in the same block for a
year - element went in there. Now bought this one and its happened
again. Block is about 3/4 years old so just about expected lifetime as
its very hard water - just my luck to catch them both !
Got an electrician in last time and will get same guy - I'm not
confident enough since my last diy job (plumbing) had a steady leak and
has ended up leaving the tiles on the kitchen floor in need of replcaing
at the water seeped slowly underneath ! Wife will insist on a pro.....

"NC" wrote in message news:xKU4c.434$sg7.202@newsfe1-win...
MrCheerful wrote:
"NC" wrote in message news:3JT4c.187$N1.178@newsfe1-win...

All,
I am on Domestic 10 elec and so my immersion tank heats the water
overnight. Yesterday I noticed that the water was cold after only a
small amount had been used, I checked the fuses etc and evrything seemed
OK. So, I put it down to using a little more than we thought and hoped
it would be hot again this morning - its not !
So, how do I go about testing the element to see if its dead ?? I am
competant with a DMM but what I am wondering is how these things
normally show they are dead - will earth short to neutral / live, will
the live/neutral resistance go up to infinity ?? If I can do this simple
test myself I can call my electrician I *know* whats wrong rather than
ask him out it tun out to be something else (like what ?!?!).

Thanks in advance,
N.


Elements are very cheap and fail regularly in hard water areas. If live
was
shorted to earth the fuse would blow. Quite often a small amount of
current
will flow through the element, so a resistance test will only help if
you
first work out what the resistance should be, in your case you are
looking
for about twenty ohms across the element. If your figure is a long way
up
from this, then the element has failed. Turn the water off, disconnect
wiring, unscrew and reverse the process to install a new one. Often not
as
easy as it sounds.

MrCheerful



Thanks - confirms my thoughts - l/n resistance is in the region of
Mega/Kilo ohms! Just my luck - rented a flat in the same block for a
year - element went in there. Now bought this one and its happened
again. Block is about 3/4 years old so just about expected lifetime as
its very hard water - just my luck to catch them both !
Got an electrician in last time and will get same guy - I'm not
confident enough since my last diy job (plumbing) had a steady leak and
has ended up leaving the tiles on the kitchen floor in need of replcaing
at the water seeped slowly underneath ! Wife will insist on a pro.....

Good, thats that sorted. Out of interest, 3 - 4 years is about average for
hard water.
I have a water softener, in twenty five years I have replaced the element
once, and that was the one which was here before the softener. The water
heater is on semi-permanently too!

mrcheerful

It is worth checking the thermostat. The contacts can burn out.

--


Regards

John


"MrCheerful" wrote in message
...

"NC" wrote in message news:xKU4c.434$sg7.202@newsfe1-win...
MrCheerful wrote:
"NC" wrote in message
news:3JT4c.187$N1.178@newsfe1-win...

All,
I am on Domestic 10 elec and so my immersion tank heats the water
overnight. Yesterday I noticed that the water was cold after only a
small amount had been used, I checked the fuses etc and evrything
seemed
OK. So, I put it down to using a little more than we thought and hoped
it would be hot again this morning - its not !
So, how do I go about testing the element to see if its dead ?? I am
competant with a DMM but what I am wondering is how these things
normally show they are dead - will earth short to neutral / live, will
the live/neutral resistance go up to infinity ?? If I can do this
simple
test myself I can call my electrician I *know* whats wrong rather than
ask him out it tun out to be something else (like what ?!?!).

Thanks in advance,
N.


Elements are very cheap and fail regularly in hard water areas. If
live
was
shorted to earth the fuse would blow. Quite often a small amount of
current
will flow through the element, so a resistance test will only help if
you
first work out what the resistance should be, in your case you are
looking
for about twenty ohms across the element. If your figure is a long
way
up
from this, then the element has failed. Turn the water off,
disconnect
wiring, unscrew and reverse the process to install a new one. Often
not
as
easy as it sounds.

MrCheerful



Thanks - confirms my thoughts - l/n resistance is in the region of
Mega/Kilo ohms! Just my luck - rented a flat in the same block for a
year - element went in there. Now bought this one and its happened
again. Block is about 3/4 years old so just about expected lifetime as
its very hard water - just my luck to catch them both !
Got an electrician in last time and will get same guy - I'm not
confident enough since my last diy job (plumbing) had a steady leak and
has ended up leaving the tiles on the kitchen floor in need of replcaing
at the water seeped slowly underneath ! Wife will insist on a pro.....


Good, thats that sorted. Out of interest, 3 - 4 years is about average
for
hard water.
I have a water softener, in twenty five years I have replaced the element
once, and that was the one which was here before the softener. The water
heater is on semi-permanently too!

mrcheerful




---
All of my outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.618 / Virus Database: 397 - Release Date: 09/03/2004

"MrCheerful" wrote in message
...



Good, thats that sorted. Out of interest, 3 - 4 years is about average
for
hard water.
I have a water softener, in twenty five years I have replaced the element
once, and that was the one which was here before the softener. The water
heater is on semi-permanently too!

Yes, just replaced the immersion in a property yesterday- 4 yrs since the
last one replaced. Had to call plumber in the end because I couldnt shift
it, and was at stage of nearly twisting the boss off the top of the
cylinder.

Much blow lamp and it eventually came free, but we did crack the solder join
where boss meets cylinder and were lucky it soldered up and sealed with new
element in place. Cylinder will have to be changed next time element goes.

Tim..

"MrCheerful" wrote in message
...

"NC" wrote in message news:xKU4c.434$sg7.202@newsfe1-win...
MrCheerful wrote:
"NC" wrote in message news:3JT4c.187$N1.178@newsfe1-win...

All,
I am on Domestic 10 elec and so my immersion tank heats the water
overnight. Yesterday I noticed that the water was cold after only a
small amount had been used, I checked the fuses etc and evrything seemed
OK. So, I put it down to using a little more than we thought and hoped
it would be hot again this morning - its not !
So, how do I go about testing the element to see if its dead ?? I am
competant with a DMM but what I am wondering is how these things
normally show they are dead - will earth short to neutral / live, will
the live/neutral resistance go up to infinity ?? If I can do this simple
test myself I can call my electrician I *know* whats wrong rather than
ask him out it tun out to be something else (like what ?!?!).

Thanks in advance,
N.


Elements are very cheap and fail regularly in hard water areas. If live
was
shorted to earth the fuse would blow. Quite often a small amount of
current
will flow through the element, so a resistance test will only help if
you
first work out what the resistance should be, in your case you are
looking
for about twenty ohms across the element. If your figure is a long way
up
from this, then the element has failed. Turn the water off, disconnect
wiring, unscrew and reverse the process to install a new one. Often not
as
easy as it sounds.

MrCheerful



Thanks - confirms my thoughts - l/n resistance is in the region of
Mega/Kilo ohms! Just my luck - rented a flat in the same block for a
year - element went in there. Now bought this one and its happened
again. Block is about 3/4 years old so just about expected lifetime as
its very hard water - just my luck to catch them both !

Some immersion heaters are specifically designed for hard (aggressive?) water:
See http://www.bes.ltd.uk/nav_graf/frames_cat.htm


Michael Chare

"Michael Chare" wrote in message
...
"MrCheerful" wrote in message
...

"NC" wrote in message
news:xKU4c.434$sg7.202@newsfe1-win...
MrCheerful wrote:
"NC" wrote in message
news:3JT4c.187$N1.178@newsfe1-win...

All,
I am on Domestic 10 elec and so my immersion tank heats the water
overnight. Yesterday I noticed that the water was cold after only a
small amount had been used, I checked the fuses etc and evrything
seemed
OK. So, I put it down to using a little more than we thought and
hoped
it would be hot again this morning - its not !
So, how do I go about testing the element to see if its dead ?? I am
competant with a DMM but what I am wondering is how these things
normally show they are dead - will earth short to neutral / live,
will
the live/neutral resistance go up to infinity ?? If I can do this
simple
test myself I can call my electrician I *know* whats wrong rather
than
ask him out it tun out to be something else (like what ?!?!).

Thanks in advance,
N.


Elements are very cheap and fail regularly in hard water areas. If
live
was
shorted to earth the fuse would blow. Quite often a small amount of
current
will flow through the element, so a resistance test will only help
if
you
first work out what the resistance should be, in your case you are
looking
for about twenty ohms across the element. If your figure is a long
way
up
from this, then the element has failed. Turn the water off,
disconnect
wiring, unscrew and reverse the process to install a new one. Often
not
as
easy as it sounds.

MrCheerful



Thanks - confirms my thoughts - l/n resistance is in the region of
Mega/Kilo ohms! Just my luck - rented a flat in the same block for a
year - element went in there. Now bought this one and its happened
again. Block is about 3/4 years old so just about expected lifetime as
its very hard water - just my luck to catch them both !

Some immersion heaters are specifically designed for hard (aggressive?)
water:
See http://www.bes.ltd.uk/nav_graf/frames_cat.htm


Well the one we just fitted was a Backer all singing all dancing stainless
steel sheathed jobby[1], which ought to last a fair while, but i bet it
doesn't. (water is v hard- blame 7 trent)

[1] = £££££

Tim..

"NC" wrote in message news:xKU4c.434$sg7.202@newsfe1-win...
MrCheerful wrote:
"NC" wrote in message
news:3JT4c.187$N1.178@newsfe1-win...


SNIP

Elements are very cheap and fail regularly in hard water areas. If
live was
shorted to earth the fuse would blow. Quite often a small amount of
current
will flow through the element, so a resistance test will only help if
you
first work out what the resistance should be, in your case you are
looking
for about twenty ohms across the element. If your figure is a long way
up
from this, then the element has failed. Turn the water off, disconnect
wiring, unscrew and reverse the process to install a new one. Often
not as
easy as it sounds.

MrCheerful



Thanks - confirms my thoughts - l/n resistance is in the region of
Mega/Kilo ohms! Just my luck - rented a flat in the same block for a
year - element went in there. Now bought this one and its happened
again. Block is about 3/4 years old so just about expected lifetime as
its very hard water - just my luck to catch them both !
Got an electrician in last time and will get same guy - I'm not
confident enough since my last diy job (plumbing) had a steady leak and
has ended up leaving the tiles on the kitchen floor in need of replcaing
at the water seeped slowly underneath ! Wife will insist on a pro.....

If you have really hard water you could expect failure in much less - in
our area a standard element providing all the hot water for a family will
fail in just over a year (just out of guarantee:-( ). Insist on one of
the aggressive water types such as (Incaloy, Backerloy , Aqualoy etc)
depending on make when it is replaced. They only cost about fifteen quid
from plumb centre rather than the usual seven or eight but last about four
times as long. Also ensure your thermostat is set at a sensible level not
screwed right up to minimise the duty times it operates. 60 degrees at the
bottom of a standard cylinder will give much higher temperatures at the top
anyway, unles you have a destratification pump (rare in domestics)

In article 3JT4c.187$N1.178@newsfe1-win,
NC wrote:
So, how do I go about testing the element to see if its dead ?? I am
competant with a DMM but what I am wondering is how these things
normally show they are dead - will earth short to neutral / live, will
the live/neutral resistance go up to infinity ??

The nominal resistance of a 3kW immersion is about 20 ohms. If it has
failed, this reading will be very much higher - how high depends on
whether the outer has failed letting in water. In bad cases, you might
have a near short - enough to take the fuse or breaker.

--
*When the chips are down, the buffalo is empty.

Dave Plowman London SW 12
RIP Acorn

"Dave Plowman" wrote in message
...
In article 3JT4c.187$N1.178@newsfe1-win,
NC wrote:
So, how do I go about testing the element to see if its dead ?? I am
competant with a DMM but what I am wondering is how these things
normally show they are dead - will earth short to neutral / live, will
the live/neutral resistance go up to infinity ??

The nominal resistance of a 3kW immersion is about 20 ohms. If it has
failed, this reading will be very much higher - how high depends on
whether the outer has failed letting in water. In bad cases, you might
have a near short - enough to take the fuse or breaker.

In all the cases i've known when the element fails through corrosion- the
outter sheath is penetrated down to the actual heating coil- water floods
in, then it takes out the RCD because of the leakage (well dead short
almost) from live to earth.

Tim..

"MrCheerful" wrote in message news:GnV4c.16150
Good, thats that sorted. Out of interest, 3 - 4 years is about average for
hard water.
I have a water softener, in twenty five years I have replaced the element
once, and that was the one which was here before the softener. The water
heater is on semi-permanently too!

May seem like a silly question, but is 3-4 years normal even when the
immersion heater is not used?, (ours is a backup for the gas boiler
which heats the tank by indirect coil).

John wrote:

"NC" wrote in message news:xKU4c.434$sg7.202@newsfe1-win...

MrCheerful wrote:

"NC" wrote in message

news:3JT4c.187$N1.178@newsfe1-win...


SNIP

Elements are very cheap and fail regularly in hard water areas. If

live was

shorted to earth the fuse would blow. Quite often a small amount of

current

will flow through the element, so a resistance test will only help if

you

first work out what the resistance should be, in your case you are

looking

for about twenty ohms across the element. If your figure is a long way

up

from this, then the element has failed. Turn the water off, disconnect
wiring, unscrew and reverse the process to install a new one. Often

not as

easy as it sounds.

MrCheerful



Thanks - confirms my thoughts - l/n resistance is in the region of
Mega/Kilo ohms! Just my luck - rented a flat in the same block for a
year - element went in there. Now bought this one and its happened
again. Block is about 3/4 years old so just about expected lifetime as
its very hard water - just my luck to catch them both !
Got an electrician in last time and will get same guy - I'm not
confident enough since my last diy job (plumbing) had a steady leak and
has ended up leaving the tiles on the kitchen floor in need of replcaing
at the water seeped slowly underneath ! Wife will insist on a pro.....


If you have really hard water you could expect failure in much less - in
our area a standard element providing all the hot water for a family will
fail in just over a year (just out of guarantee:-( ). Insist on one of
the aggressive water types such as (Incaloy, Backerloy , Aqualoy etc)
depending on make when it is replaced. They only cost about fifteen quid
from plumb centre rather than the usual seven or eight but last about four
times as long. Also ensure your thermostat is set at a sensible level not
screwed right up to minimise the duty times it operates. 60 degrees at the
bottom of a standard cylinder will give much higher temperatures at the top
anyway, unles you have a destratification pump (rare in domestics)



Thanks for advice - currently waiting for my electrician to get in touch
when he's back from hols - until then its the shower, and kettle for
washing up !

In article ,
(Mike Hall) writes:
"MrCheerful" wrote in message news:GnV4c.16150
Good, thats that sorted. Out of interest, 3 - 4 years is about average for
hard water.
I have a water softener, in twenty five years I have replaced the element
once, and that was the one which was here before the softener. The water
heater is on semi-permanently too!

May seem like a silly question, but is 3-4 years normal even when the
immersion heater is not used?, (ours is a backup for the gas boiler
which heats the tank by indirect coil).

Should last forever (or at least outlast the cylinder).

--
Andrew Gabriel

On Mon, 15 Mar 2004 19:53:54 -0800, Mike Hall wrote:

"MrCheerful" wrote in message news:GnV4c.16150
Good, thats that sorted. Out of interest, 3 - 4 years is about average for
hard water.
I have a water softener, in twenty five years I have replaced the element
once, and that was the one which was here before the softener. The water
heater is on semi-permanently too!

May seem like a silly question, but is 3-4 years normal even when the
immersion heater is not used?, (ours is a backup for the gas boiler
which heats the tank by indirect coil).

I would have thought you should get longer than that.
Water is some areas can be quite corrosive and you may find that paying
slightly more for a corrosion 'resistant' unit will be worthwhile.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

In article ,
Mike Hall wrote:
May seem like a silly question, but is 3-4 years normal even when the
immersion heater is not used?, (ours is a backup for the gas boiler
which heats the tank by indirect coil).

Mine didn't work after about 10 years or so - apart from a test when
installed. Can't say when it *actually* failed though. I replaced it with
a stainless one and do check it occasionally now.

--
*Laugh alone and the world thinks you're an idiot.

Dave Plowman London SW 12
RIP Acorn

"Ed Sirett" wrote in message
news
On Mon, 15 Mar 2004 19:53:54 -0800, Mike Hall wrote:

"MrCheerful" wrote in message news:GnV4c.16150
Good, thats that sorted. Out of interest, 3 - 4 years is about average
for
hard water.
I have a water softener, in twenty five years I have replaced the
element
once, and that was the one which was here before the softener. The
water
heater is on semi-permanently too!

May seem like a silly question, but is 3-4 years normal even when the
immersion heater is not used?, (ours is a backup for the gas boiler
which heats the tank by indirect coil).

I would have thought you should get longer than that.
Water is some areas can be quite corrosive and you may find that paying
slightly more for a corrosion 'resistant' unit will be worthwhile.

Both Dave P and I did specify in our previous posts that we have and always
have had the corrosion proof elements, but they still 'wear out' in 3-4 yrs.
A standard one probably would only last 12months.....

Tim..