electric shower not working - no light on

DeDoc · 14-05-2011 5:46pm #1

Hi,

I've an electric shower fitted in the bathroom - about 3 years old. Gets used once or twice a day on average. There is a pull cord isolation switch in the ceiling.

Today the shower won't work. The light on the ceiling switch comes on, but the light on the wall-unit doesn't.

I've opened up both the ceiling switch and the wall-unit to have a look. The ceiling unit appears perfectly normal - no loose connections or anything. The wall-unit appears generally ok, but there is a fair bit of graphite around - I assume that is normal from the brushes wearing?

Is there a fuse within the wall-unit that I should be checking or could be replacing? Or any suggestion as to what part might be malfunctioning and needs replacing?

I have an identical unit downstairs that doesn't get used much (till today

) - so I could temporarily swap out components to test them I suppose. I don't have a multi-meter at hand, but can get one if needed, to test current flow etc.

Any help appreciated.

The shower unit is a triton t90xr by the way

evosteo · 14-05-2011 6:16pm

very common problem,

simply replace the pull cord switch

due to the high currents going through the switch it causes heat and the plastic around the rocker in the switch to become maluable and interfers with the switching of the device. so even though the pull cord indicator light is on the rocker inside isnt making complete contact

IF YOU DONT KNOW WHAT YOUR DOING GET SOMEBODY WHO DOES AS ITS VERY DANGEROUS.

Switch should cost you bout 30 quid

stephen

DeDoc · 14-05-2011 7:35pm

Thanks for the prompt reply stephen

I presume I can the switch in any good electrical suppliers, or maybe even in homebase etc?

I'm confident enough I can handle the disconnection of one switch and replacement with another - switch off at the fusebox, take my time, double and triple check the wiring and off we go!

What you say actually makes complete sense, as I recall the switch being a little 'stiff' recently - which would be understandable if the plastic had melted somewhat.

Bruthal · 14-05-2011 7:38pm

If the shower is actually being turned on and the ceiling neon is still on, then the ceiling switch is not the problem, at least not the internals of the switch anyway. This does not mean there is not a connection problem at the ceiling switch, but this would usually show itself as badly burnt connections if the shower was previously working for a length of time with that switch. If a bad switch internal rocker connection is able to keep the ceiling switch neon on, then it should have the shower one on also while the shower is not actualy trying to be switched on. All assuming the neon is on the switched side.

Loose connections on the outgoing side of the switch would leave the pull chord neon on, but bad contacts connection in the seitch itself, which is before the neon, and the neon would go off when the shower is started as the connection fails from the load.

An electrician and multimeter would easily find where or why the connection is failing before the shower unit neon.

Bruthal · 14-05-2011 8:09pm

DeDoc wrote: »

I'm confident enough I can handle the disconnection of one switch and replacement with another - switch off at the fusebox, take my time, double and triple check the wiring and off we go!

What you say actually makes complete sense, as I recall the switch being a little 'stiff' recently - which would be understandable if the plastic had melted somewhat.

While swapping the switch could fix it, i would not assume its the switch for certain, because if the switch was connected the right way round, (neon on pull chord goes off when switch is turned off), then the neon will definitely go off if the switch has an internal problem when the shower is tried to be used.

And also the shower neon should be on of the pullchord one is on if the connection problem is before the pullchord neon, again assuming the pullchord neon is on the swithed side.

The real tests are to get a multimeter and check for supply at shower unit connections, and if power is there, try switching shower on, and see if supply is still at shower unit connections. If it is, then the problem is further on, as in something in the shower. Very simple tests for a competent electrician.

You could chance buying a switch, but it is not certain without doubt its that.

If the pullchord neon is on, and the shower one is off, then the problem is between the 2 neons.

evosteo · 15-05-2011 5:02pm

theres alot of different makes of pullcord switch, some cheap, some quality, but what i can say to you is iv seen where the pull cord neon is on but no light at the shower unit.

honestly i can`t say how but i only assumed that the neutral rocker was stuck and the live feed only made connection somehow showing the neon flickering. these neons use very little current i assume.

as ya said earlier could also be loose connections in the switch.

could be a mouse chewed through the cable :eek:

all speculation really:rolleyes:

Bruthal · 15-05-2011 7:03pm

evosteo wrote: »

all speculation really:rolleyes:

You could well be right, all im saying is i would test the switch and shower first before just buying a switch to find the problem is a connection in the shower unit itself.

If 2 neons are solidly connected in parallel its hard to see one lighting and the other not if both neon`s are ok. We dont know if its a shower where the shower unit neon is on once the pullchord is on, like on a t90. Or if the OP actually tried operating the shower or just left it because the neon on it was off. Speculation is often all that can be offered here without very precise info.

A switch change could fix it though as said, if the OP wants to try it without testing anything.

Bruthal · 15-05-2011 7:23pm

Anyway, tests for the OP to do,, with pullchord on. (Or just buy a switch and hope its that)

If the pullchord neon is lighting, and then switching on the shower unit puts the pullchord neon off, then there is a problem before the pullchord neon, probably within the switch.

If the shower unit is turned on, and the pullchord neon stays on, then the problem is after the pullchord neon, either the pullchord load side connections are loose, or loose connections or fault within the shower unit itself. No speculation there.

Dufftronic · 15-05-2011 8:00pm

Get that multi meter you mentioned. It will tell you if you are getting voltage on the load side of the isolation switch. If you are, its your shower at fault and not the isolation switch. If there is no voltage, your switch is the problem. It's also important that the pull cord switch is only being used when the shower is off. Don't use it to power off your shower in normal usage, thats what the button on the shower unit is for.

DeDoc · 15-05-2011 8:25pm

The shower when working will show both lights (shower unit and pull cord unit) on once the pull cord is switched on. Currently, only the light on the ceiling unit comes on, not the light on the shower unit. The shower unit on/off switch doesn't do anything (at the moment!)

I enclose the diagram from the shower manual. I'll test this tomorrow when I get a multi-meter

Dufftronic · 15-05-2011 8:40pm

the problem is probably just the switch. Put the meter across the load side (the shower side) and check that you are getting around 230V between live and neutral. You should never do an electrical job without a multimeter tbh, its just not worth the risk.

Bruthal · 15-05-2011 8:43pm

DeDoc wrote: »

The shower when working will show both lights (shower unit and pull cord unit) on once the pull cord is switched on. Currently, only the light on the ceiling unit comes on, not the light on the shower unit. The shower unit on/off switch doesn't do anything (at the moment!)

I enclose the diagram from the shower manual. I'll test this tomorrow when I get a multi-meter

Did you look up at the pull chord neon as you turn on the shower unit switch as you would to have a shower, and see does the neon on the pull chord stay on?

Bruthal · 15-05-2011 8:47pm

Dufftronic wrote: »

the problem is probably just the switch. Put the meter across the load side (the shower side) and check that you are getting around 230V between live and neutral. You should never do an electrical job without a multimeter tbh, its just not worth the risk.

If there is in fact a bad connection at the switch, 230v can still show up on it with no load on the circuit. Turning on the shower and seeing does the neon stay on is a very quick and easy test for the user to do.

If the neon stays on with the shower fully turned on, then the problem is no further upstream than the load side of the pullchord, and is somewhere either at or after the pullchord load side. (Unless anyone can think of a way the pullchord neon can be on with the shower fully on, and the fault before the pullchord neon)?

Bruthal · 16-05-2011 9:17am

DeDoc wrote: »

The shower when working will show both lights (shower unit and pull cord unit) on once the pull cord is switched on. Currently, only the light on the ceiling unit comes on, not the light on the shower unit. The shower unit on/off switch doesn't do anything (at the moment!)

Just try switching the shower unit on and see if the pullchord neon goes out, as this can indicate if the problem is before or after the pullchord neon. The first thing after the pullchord neon is the pullchord load terminals.

Here is a simplified electrical diagram of a shower and pullchord.

Now looking at that, it can be seen that if the pullchord neon is on and you try running the shower, if the fault is before the pullchord neon, then the pullchord neon should go off.

If the fault is in the pullchord load terminals or after, then the pullchord neon will remain on when you try running the shower, suggesting the pullchord is ok.

The shower unit on/off switch in reality only brings on the pump and solenoid and does nothing more, but the neons are in parallel as in the diagram. The elements are then brought on/off by the water pressure switch, so the heavy load is not directly switched by the shower unit on/off switch as in my simple diagram above, but the pullchord neon behaviour should still indicate the fault location is either before or after the pullchord neon.

It could easily be the switch, all im saying is its a simple test which can indicate if it is or not. I am not a big fan of pullchords for loads as big as showers anyway.

If it is the switch thats the problem, and no signs of burning are present, its probably a mechanical problem in it as the lower quality ones suffer from this in the string pull mechanism. You are probably best leaving the pullchord switches on all the time, only switching off for servicing the showers.

DeDoc · 16-05-2011 7:12pm

Update:

Just home. The on-off button on the shower unit causes the pull-chord neon to go off when pressed. Press it again and the pull-chord neon goes on again. The shower neon stays on all the time

If I read the above correctly, this suggests that the pull-cord unit is faulty - correct? Will test with multi-meter later tonight or in the morning. Need to eat!

Bruthal · 16-05-2011 8:44pm

DeDoc wrote: »

Update:

Just home. The on-off button on the shower unit causes the pull-chord neon to go off when pressed. Press it again and the pull-chord neon goes on again. The shower neon stays on all the time

If I read the above correctly, this suggests that the pull-cord unit is faulty - correct? Will test with multi-meter later tonight or in the morning. Need to eat!

What it suggests is that the problem is before the pull chord neon, it could be the switch mechanism, or it could be the supply side connections of the pull chord, or it could be down at the MCB board.

The next thing to do is test all the terminals in the pull chord to see they are tight with a screw driver, with the circuit switched off.

Once thats done, switch circuit back on and test again to see neon is going off at pull chord when try to turn shower on as above.

Now test the pull chord supply side terminals with a multimeter, and if your getting 230v, then while still holding the probes on the terminals, get someone to turn on the shower unit again. If it remains at 230v then the switch is probably faulty. If it drops to near 0v then the problem is probably down at the MCB board.

Looking like the switch anyway, but better to do the simple tests and confirm, than just buy one and its not that. Post back what you get on testing switch. Switch might have supply and load for each side written beside terminals so you know which is which, or just switch off the pullchord and the supply side will still be live.

DeDoc · 17-05-2011 3:09pm

Ok - just tested it now.

Getting 235V on the supply side, both before and after putting the shower unit on. Switching the shower unit on (after switching on the pull cord) causes the pullcord neon to go off, but there is still 235V on the supply side. Voltage on the load side is ~ 85V

The boards downstairs were all fitted brand new at the same time as the shower (~ 3.5 years ago) so I suspected they weren't the problem.

Any reason I shouldn't be going out to buy a replacement switch now?

Bruthal · 17-05-2011 3:12pm

DeDoc wrote: »

Ok - just tested it now.

Getting 235V on the supply side, both before and after putting the shower unit on. Switching the shower unit on (after switching on the pull cord) causes the pullcord neon to go off, but there is still 235V on the supply side. Voltage on the load side is ~ 85V

The boards downstairs were all fitted brand new at the same time as the shower (~ 3.5 years ago) so I suspected they weren't the problem.

Any reason I shouldn't be going out to buy a replacement switch now?

No its the switch alright like evosteo said, so a new one will fix it. Its good to confirm though with simple tests as its not the only possibility.

Dufftronic · 17-05-2011 3:23pm

yeah, go get the new switch. Contacts probably got damaged on the load side by pulling the cord switch while the shower was still on.

Bruthal · 17-05-2011 3:32pm

Id say its more likely the mechanics of the mechanism is sticking, shower switches rarely actualy break the load, so if they are switched a few times on load they should be well able for that as they are rated to break such a load.

The fact the multimeter read 85 volts on the load side of pullchord means the neutral contact in the pullchord switch is actually completely open circuited. If you test between live and a now completely isolated length of neutral wire thats connected into the switched off shower then 85 volts would easily be read.

If you get the removed old switch and use continuity from load to supply on live, then on neutral, id say the neutral will show open circuit with the switch in the on position.

Dufftronic · 17-05-2011 3:42pm

robbie7730 wrote: »

Id say its more likely the mechanics of the mechanism is sticking, shower switches rarely actualy break the load, so if they are switched a few times on load they should be well able for that as they are rated to break such a load.

I only mentioned it because a friend of mine used to use the pull cord to turn off his shower (on load) on a daily basis. I told him that the switch isn't designed to work in this way, which is why his broke.

Bruthal · 17-05-2011 3:46pm

Dufftronic wrote: »

I only mentioned it because a friend of mine used to use the pull cord to turn off his shower (on load) on a daily basis. I told him that the switch isn't designed to work in this way, which is why his broke.

Yes switching the pullchord off all the time on load certainly wouldnt be recommended, no doubt there about that. The push button in them showers does not break the load either, that switch just opens the solenoid, and starts the pump. The pressure from the water flow now switches on a pressure switch, and its that which does the switching of the main load (elements)

Now for more useless info..

If you get a multimeter set to measure mains voltage, one probe into live in a socket, and the other into a cup of water, just the tip into the water, you will read up to 100v on that test even though the cup of water is totally isolated from anything, because of the extreme high impedence of a digital multimeter. It is very easy to see why when its shown as a circuit and the resistances are put in for the multimeter in series with the extremely high resistance through the cup of water and the cup itself.

So in the above where the OP got 85, it would make you think a bad connection in the pullchord. But in reality its likely it has a complete open circuit present. Anything well below the 230v with a digital meter suggests an open circuit is present.

M cebee · 17-05-2011 3:51pm

best thing he can do is get a qualified electrician

country's full of em

cordub · 17-05-2011 3:55pm

M cebee wrote: »

best thing he can do is get a qualified electrician

country's full of em

BEST ADVISE i have heard in this thread !!!Electricty KILLS esp electric showers, Pay the electrician you life is worth that;);););););)

evosteo · 17-05-2011 4:14pm

when you replace the old switch with a new one, if your interested, open up the black back part of the switch, should be 2 or 4 screws holding it on.

have a peak inside urself and see can you see any obvious signs of the melting. may only be just slightly warped plastic. may also have gone dark too.

be no harm to throw a pic up of it for other people for future reference;)

stephen

Bruthal · 17-05-2011 4:19pm

I seen a few of them just jam, the mechanics are just to finicky for a 40 amp switching unit operated with a string. Would be interesting to see did it show any signs of heating alright. Have yet to see a wall switch version jam though. Much better than the pullchords.

evosteo · 17-05-2011 4:31pm

+1 ^^^^^

M cebee · 17-05-2011 5:06pm

no disrespect-but some people posting questions on here are not trained electricians

what if someone gets hurt troubleshooting

evosteo · 17-05-2011 5:16pm

is it not up to them as grown adults to make that decision themselves?????

if there was something wrong with, lets say the plumbing in my house, id also try research the answer to the problem.

however if i wasnt comfortable doing something id get somebody who did know what they were doing to do the job right.

i dont think anybody tells people to do anything, only just speculative recomendations based on information and experience.

that is all

Barr · 17-05-2011 5:17pm

Hi All

I have a Mira Zest that is about 6 years old.

Its been giving trouble the last few weeks in that sometime when you try and turn the dial it was not working at all. It could take 5 or 6 attempts before any water would come out.

Now its not coming on at all.

Mira are looking for €80 plus parts. Is it worth the money given the age?

Should I just get an electrician to replace it with a whole new unit and bypass Mira altogether?

What ye think.

Thanks

Barr · 17-05-2011 5:20pm

Please delete the above it was meant as a new thread.

electric shower not working - no light on

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