After an upstairs plumbing leak at my son's house the light switch in
one of the downstairs rooms has stopped working. The switch itself seems
ok but it doesn't turn the light off.
Originally, water poured down through the ceiling rose, but nothing
tripped at the time, and it has been hanging loose for a couple of weeks
in the hope that it would dry out.
Should I just replace the switch and the rose or can anyone pinpoint
what might have happened? Thanks for any advice.

After an upstairs plumbing leak at my son's house the light switch in
one of the downstairs rooms has stopped working. The switch itself seems
ok but it doesn't turn the light off.
Should I just replace the switch and the rose or can anyone pinpoint
what might have happened? Thanks for any advice.

Other than maybe it being a 3-plate system, and the live loop is
shorted to the switch return, not a clue :-}

Could the switch have welded itself together ? (i.e. does it feel like
it's switching normally, or a bit askew)

"stuart noble" wrote in message
news
After an upstairs plumbing leak at my son's house the light switch in one
of the downstairs rooms has stopped working. The switch itself seems ok
but it doesn't turn the light off.
Originally, water poured down through the ceiling rose, but nothing
tripped at the time, and it has been hanging loose for a couple of weeks
in the hope that it would dry out.
Should I just replace the switch and the rose or can anyone pinpoint what
might have happened? Thanks for any advice.

It may be that the rose/pendant was disconnected when the leak was
discovered and then re connected wrongly

If the pendant had been reconnected to the loop live and neutral rather than
switched live and neutral it would behave as you describe

Tony

TMC wrote:
"stuart noble" wrote in message
news
After an upstairs plumbing leak at my son's house the light switch in one
of the downstairs rooms has stopped working. The switch itself seems ok
but it doesn't turn the light off.
Originally, water poured down through the ceiling rose, but nothing
tripped at the time, and it has been hanging loose for a couple of weeks
in the hope that it would dry out.
Should I just replace the switch and the rose or can anyone pinpoint what
might have happened? Thanks for any advice.

It may be that the rose/pendant was disconnected when the leak was
discovered and then re connected wrongly

If the pendant had been reconnected to the loop live and neutral rather than
switched live and neutral it would behave as you describe

Tony



No, the wiring wasn't touched after the leak, other than the bulb being
removed. As I said, the switch itself feels normal and, AFAIK didn't get
wet in tne first place.

"stuart noble" wrote in message
...
TMC wrote:
"stuart noble" wrote in message
news
After an upstairs plumbing leak at my son's house the light switch in
one of the downstairs rooms has stopped working. The switch itself seems
ok but it doesn't turn the light off.
Originally, water poured down through the ceiling rose, but nothing
tripped at the time, and it has been hanging loose for a couple of weeks
in the hope that it would dry out.
Should I just replace the switch and the rose or can anyone pinpoint
what might have happened? Thanks for any advice.

It may be that the rose/pendant was disconnected when the leak was
discovered and then re connected wrongly

If the pendant had been reconnected to the loop live and neutral rather
than switched live and neutral it would behave as you describe

Tony

No, the wiring wasn't touched after the leak, other than the bulb being
removed. As I said, the switch itself feels normal and, AFAIK didn't get
wet in tne first place.


Take the switch off and disconnect either the feed or return and see if the
light goes off.
If it don't then its not the switch

I would do this live but that's just me

Probably best to isolate first disconnect a wire and insulate then put the
power back on

Tony

TMC wrote:
"stuart noble" wrote in message
...
TMC wrote:
"stuart noble" wrote in message
news After an upstairs plumbing leak at my son's house the light switch in
one of the downstairs rooms has stopped working. The switch itself seems
ok but it doesn't turn the light off.
Originally, water poured down through the ceiling rose, but nothing
tripped at the time, and it has been hanging loose for a couple of weeks
in the hope that it would dry out.
Should I just replace the switch and the rose or can anyone pinpoint
what might have happened? Thanks for any advice.
It may be that the rose/pendant was disconnected when the leak was
discovered and then re connected wrongly

If the pendant had been reconnected to the loop live and neutral rather
than switched live and neutral it would behave as you describe

Tony
No, the wiring wasn't touched after the leak, other than the bulb being
removed. As I said, the switch itself feels normal and, AFAIK didn't get
wet in tne first place.


Take the switch off and disconnect either the feed or return and see if the
light goes off.
If it don't then its not the switch

I would do this live but that's just me

Probably best to isolate first disconnect a wire and insulate then put the
power back on

Tony



Cheers. I'll try that tomorrow.

stuart noble wrote:
TMC wrote:
"stuart noble" wrote in message
...
TMC wrote:
"stuart noble" wrote in message
news

After an upstairs plumbing leak at my son's house the light switch in
one of the downstairs rooms has stopped working. The switch itself seems
ok but it doesn't turn the light off.
Originally, water poured down through the ceiling rose, but nothing
tripped at the time, and it has been hanging loose for a couple of weeks
in the hope that it would dry out.
Should I just replace the switch and the rose or can anyone pinpoint
what might have happened? Thanks for any advice.
It may be that the rose/pendant was disconnected when the leak was
discovered and then re connected wrongly

If the pendant had been reconnected to the loop live and neutral rather
than switched live and neutral it would behave as you describe

Tony
No, the wiring wasn't touched after the leak, other than the bulb being
removed. As I said, the switch itself feels normal and, AFAIK didn't get
wet in tne first place.


Take the switch off and disconnect either the feed or return and see if the
light goes off.
If it don't then its not the switch

I would do this live but that's just me

Probably best to isolate first disconnect a wire and insulate then put the
power back on

Tony



Cheers. I'll try that tomorrow.

Sounds like the water has created a short between live and
switched live. It might be conducting through the water, or maybe
as the water evaporated a conductive carbon track was created where
the water went o/c.

I'd strip back the ends of the switch cable at the pendant fitting
and
reconnect. If the light comes on with the switch cable removed, then
the rose will be faulty, and its connector strip need replacing.


NT

wrote:
stuart noble wrote:
TMC wrote:
"stuart noble" wrote in message
...
TMC wrote:
"stuart noble" wrote in message
news

After an upstairs plumbing leak at my son's house the light switch in
one of the downstairs rooms has stopped working. The switch itself seems
ok but it doesn't turn the light off.
Originally, water poured down through the ceiling rose, but nothing
tripped at the time, and it has been hanging loose for a couple of weeks
in the hope that it would dry out.
Should I just replace the switch and the rose or can anyone pinpoint
what might have happened? Thanks for any advice.
It may be that the rose/pendant was disconnected when the leak was
discovered and then re connected wrongly

If the pendant had been reconnected to the loop live and neutral rather
than switched live and neutral it would behave as you describe

Tony
No, the wiring wasn't touched after the leak, other than the bulb being
removed. As I said, the switch itself feels normal and, AFAIK didn't get
wet in tne first place.

Take the switch off and disconnect either the feed or return and see if the
light goes off.
If it don't then its not the switch

I would do this live but that's just me

Probably best to isolate first disconnect a wire and insulate then put the
power back on

Tony


Cheers. I'll try that tomorrow.

Sounds like the water has created a short between live and
switched live. It might be conducting through the water, or maybe
as the water evaporated a conductive carbon track was created where
the water went o/c.

I'd strip back the ends of the switch cable at the pendant fitting
and
reconnect. If the light comes on with the switch cable removed, then
the rose will be faulty, and its connector strip need replacing.


NT

Thanks. In theory the fault should be in the rose because that's the bit
that got flooded. Presumably if I disconnect the switch at the wall and
the light stays on, I'll need a new rose. If not, I'll need a new
switch. Or maybe it's not as simple as that...

stuart noble wrote:
wrote:
stuart noble wrote:
TMC wrote:
"stuart noble" wrote in message
...
TMC wrote:
"stuart noble" wrote in message
news

After an upstairs plumbing leak at my son's house the light switch in
one of the downstairs rooms has stopped working. The switch itself seems
ok but it doesn't turn the light off.
Originally, water poured down through the ceiling rose, but nothing
tripped at the time, and it has been hanging loose for a couple of weeks
in the hope that it would dry out.
Should I just replace the switch and the rose or can anyone pinpoint
what might have happened? Thanks for any advice.
It may be that the rose/pendant was disconnected when the leak was
discovered and then re connected wrongly

If the pendant had been reconnected to the loop live and neutral rather
than switched live and neutral it would behave as you describe

Tony
No, the wiring wasn't touched after the leak, other than the bulb being
removed. As I said, the switch itself feels normal and, AFAIK didn't get
wet in tne first place.

Take the switch off and disconnect either the feed or return and see if the
light goes off.
If it don't then its not the switch

I would do this live but that's just me

Probably best to isolate first disconnect a wire and insulate then put the
power back on

Tony


Cheers. I'll try that tomorrow.

Sounds like the water has created a short between live and
switched live. It might be conducting through the water, or maybe
as the water evaporated a conductive carbon track was created where
the water went o/c.

I'd strip back the ends of the switch cable at the pendant fitting
and
reconnect. If the light comes on with the switch cable removed, then
the rose will be faulty, and its connector strip need replacing.


NT

Thanks. In theory the fault should be in the rose because that's the bit
that got flooded. Presumably if I disconnect the switch at the wall and
the light stays on, I'll need a new rose. If not, I'll need a new
switch. Or maybe it's not as simple as that...

the fault could be in the cable end or the rose, both got flooded
together. I'd disconnect the cable at the rose and test, then you'll
know which is the problem. A bad cable can be cut back and
reconnected.


NT

Sounds like the water has created a short between live and
switched live. It might be conducting through the water, or maybe
as the water evaporated a conductive carbon track was created where
the water went o/c.


Spot on.
All the connections were bone dry, but covered in salts. Wiggled the
wiring and there was a bit of snap crackle and pop before the bulb blew.
Fitted new pendant and all was well. Seems like the dry salts were
behaving just like water. Well, I've learnt something today! Thanks for
that.