Shower switch burnt out

P_1

Does anyone have a ball park figure for how much it would cost to replace a burnt out shower switch? The shower has stopped working on me and this seems to be the problem. I'd do it myself but frankly I haven't got a clue how to.

Steve

Are you talking about a ceiling pull-cord switch?

Not expensive but figuring out why it failed would be more important than replacing it.

http://www.eurosales.ie/products/1298.html

2011

Steve wrote: »

Are you talking about a ceiling pull-cord switch?

Not expensive but figuring out why it failed would be more important than replacing it.

http://www.eurosales.ie/products/1298.html

These switches frequently fail. Assuming it is an instantaneous shower it is generally the largest single load in the installation. Many have low quality isolation switches which they switch off when not in use which can shorten the life of the unit considerably. Even more damaging is operating the switch under load conditions.

I would recommend a high quality switch such as MK.

P_1

Steve wrote: »

Are you talking about a ceiling pull-cord switch?

Not expensive but figuring out why it failed would be more important than replacing it.

http://www.eurosales.ie/products/1298.html

It's a switch on the wall outside the bathroom. I'm guessing the most expensive will be the call out and labour charge

Sleeper12

P_1 wrote: »

It's a switch on the wall outside the bathroom. I'm guessing the most expensive will be the call out and labour charge

As "2011" says make sure you get a good quality switch. The very cheap ones can't handle the load. Personally I prefer to fit 50amp rather than 45amp when I can get them.
As for your actual question on price. Best option is ring 2 or 3 electricians & ask for a quote over the phone. I would be expecting to pay €100 supplied & fitted give or take a little.

Stoner

P_1 wrote:

It's a switch on the wall outside the bathroom. I'm guessing the most expensive will be the call out and labour charge

Switch on the wall is the only way to go imo.

I use to use mk single gang units 45amp without issue.

Pull cords are too much trouble imo.

Risteard81

Stoner wrote: »

Pull cords are too much trouble imo.

I would certainly agree in relation to cheap pull cords, but good quality 50A pull cords such as the Crabtree or Click Polar offerings are actually very good and reliable.

Steve

2011 wrote: »

These switches frequently fail.

Fail mechanically or electrically?

I read 'burnt out' as an electrical fail as opposed to the string falling off

2011

Steve wrote: »

Fail mechanically or electrically?

I read 'burnt out' as an electrical fail as opposed to the string falling off

Generally switches start to fail mechanically which leads to an electrical failure.

The "burn out" formula = the square of the current by the resistance.

or I^2 R, (watts)

An instantaneous shower (which I assume this is) has a high current (a 9.5 kW shower draws around 40 amps). So if the contacts of the switch don't have to have a very high resistance to result in quite a bit of heat being generated.

Mechanical wear can cause the resistance of the switch to increase. This can be exacerbated by operating the switch under land conditions. Frequent operation won't help either.

Steve

I get all that, these switches would not normally be expected to open under load though. Which was why I asked was it more prone to mechanical failure.
In fairness, even 45A resistive is not a big deal to break, inductive is a whole different story..

2011

Steve wrote: »

I get all that, these switches would not normally be expected to open under load though. Which was why I asked was it more prone to mechanical failure.
In fairness, even 45A resistive is not a big deal to break, inductive is a whole different story..

This switch costs €6.84 + VAT.
If you pay that little for a switch and you switch it on and off once a day for several years the chances of failure are high.
When I worked as an electrician I replaced a lot of cheap shower switches like this.
I can not recall replacing an MK or Crabtree equivalent. You get what you pay for.

P_1

So out of interest how much would an MK or Crabtree switch set you back? Bearing in mind that I'm currently in a rental and the LL is unlikely to invest too much in the place.

2011

P_1 wrote: »

So out of interest how much would an MK or Crabtree switch set you back? Bearing in mind that I'm currently in a rental and the LL is unlikely to invest too much in the place.

In the UK they cost £10.31INC VAT

Steve

2011 wrote: »

This switch costs €6.84 + VAT.
If you pay that little for a switch and you switch it on and off once a day for several years the chances of failure are high.
When I worked as an electrician I replaced a lot of cheap shower switches like this.
I can not recall replacing an MK or Crabtree equivalent. You get what you pay for.

Not doubting you, just thinking with my engineer and devils advocate hat on as if I was asked to risk assess one.

I don't know anyone who would operate the switch *every time* the shower is used. Would you not agree? I would say these are operated very infrequently?

P_1

Steve wrote: »

Not doubting you, just thinking with my engineer and devils advocate hat on as if I was asked to risk assess one.

I don't know anyone who would operate the switch *every time* the shower is used. Would you not agree? I would say these are operated very infrequently?

Do you mean turning it on before you use the shower and turning it off afterwards? I must be the exception then as that's what I was doing 90% of the time. I wonder if that's what broke it

Steve

P_1 wrote: »

So out of interest how much would an MK or Crabtree switch set you back? Bearing in mind that I'm currently in a rental and the LL is unlikely to invest too much in the place.

Kellihers are MK agents for Ireland, can't find it on the website but if you call them they will quote you.

http://www.kellihers.com/

2011

Steve wrote: »

I don't know anyone who would operate the switch *every time* the shower is used.

I do, my old man always does this. He insists that it is safer to switch it off when not in use. I think he is on his third switch now (no I'm not joking). Strange behavior (especially for an electrical engineer).

Anecdotaly I would say that lot of older people do this sort of thing.

Would you not agree? I would say these are operated very infrequently?

In my house, yes.

Steve

P_1 wrote: »

Do you mean turning it on before you use the shower and turning it off afterwards? I must be the exception then as that's what I was doing 90% of the time. I wonder if that's what broke it

It's very possible.

I know the rigors that stuff like this has to go through to pass CE and be approved for use so am disappointed when I hear a tale such as yours. As you are renting, you can't go to the original installer and claim back.

I guess that they bank on for the sake of less than €20 it's not worth the hassle.

Stoner

Steve wrote:

I don't know anyone who would operate the switch *every time* the shower is used. Would you not agree? I would say these are operated very infrequently?

People do use them all the time though.

This is an old can of worms tbh. It's going to get into the regs etc and go nowhere again imo

For my part they are there for isolation to allow someone to work on the shower.

But there is a counter argument.

enfant terrible

Stoner wrote: »

People do use them all the time though.

This is an old can of worms tbh. It's going to get into the regs etc and go nowhere again imo

For my part they are there for isolation to allow someone to work on the shower.

But there is a counter argument.

Should the switch be left on permanently.

Sleeper12

enfant terrible wrote: »

Should the switch be left on permanently.

Most if not all electricians say to leave it on. The pull cords in particular aren't designed to be turned on & off 4 or 5 times per day.
Families have rows about this on a daily basis. What is clouding the issue even more is that all the latest electric showers have an led that is still on when shower is off. So now the homeowner is looking at 2 leds, one on shower & one on switch. To them they are wasting "Hundreds of euro per year". I'm sure this is a ploy from the manufactures to keep the switch turned off.

Edit: Any possible savings on turning this tiny led off will be far outstripped by the cost of replacing the pull cord on a regular basis.

enfant terrible

Sleeper12 wrote: »

Most if not all electricians say to leave it on. The pull cords in particular aren't designed to be turned on & off 4 or 5 times per day.
Families have rows about this on a daily basis. What is clouding the issue even more is that all the latest electric showers have an led that is still on when shower is off. So now the homeowner is looking at 2 leds, one on shower & one on switch. To them they are wasting "Hundreds of euro per year". I'm sure this is a ploy from the manufactures to keep the switch turned off.

Edit: Any possible savings on turning this tiny led off will be far outstripped by the cost of replacing the pull cord on a regular basis.

Thanks Sleeper,

Would the shower then not be in stand by mode?

We're always been told to plug out our tvs as stand by mode uses a lot of electricity apparently.

Sleeper12

enfant terrible wrote: »

Thanks Sleeper,

Would the shower then not be in stand by mode?

We're always been told to plug out our tvs as stand by mode uses a lot of electricity apparently.

I'm not an electrician so happy to be corrected here.

Your DVD player Sky box etc, are still consuming electricity in standby mode. Up to 25% in some cases I think. The brains of the Sky Box is always on & always thinking. What day is it? do I need to record something today etc. This consumes power. But your electric shower is either on or off. Some showers do have pcb boards but the shower doesn't need to worry about timers or anything like that so off should mean off.
I have seen faulty power rather than electric showers with the motor running when the power button is turned off though. Usually the pcb board is faulty.

Steve

The lamps are generally neon on the switch and on the shower. They are used to indicate the presence of AC voltage.

Typically they use about 1mA which by rough calculation would cost about €0.30 per year if left on 24/365.

Think of the shower switch as a backup - similar to a cooker switch. It is a means of removing power when something goes wrong or for maintenance.

2011

Steve wrote: »

The lamps are generally neon on the switch and on the shower. They are used to indicate the presence of AC voltage.

Typically they use about 1mA which by rough calculation would cost about €0.30 per year if left on 24/365.

You could alway disconnect the lamp and save a cool 30 cent :cool:

Steve

2011 wrote: »

You could alway disconnect the lamp and save a cool 30 cent :cool:

Yeah but a REC would charge €100 for the call out... short wait of 300 years then profit!! :cool:

(assuming you never have to replace the switch )

enfant terrible

Steve wrote: »

The lamps are generally neon on the switch and on the shower. They are used to indicate the presence of AC voltage.

Typically they use about 1mA which by rough calculation would cost about €0.30 per year if left on 24/365.

Think of the shower switch as a backup - similar to a cooker switch. It is a means of removing power when something goes wrong or for maintenance.

The cooker switch on the wall should be left on too should it?

P_1

Well the wiring on the back was a burnt mess but it's been fixed.

Armchair Andy

Does the proximity of the backing box (steel more so than dry lining) bear any difference to the lifetime of one of these switches? (Heat wise).
I'm sure a 2 gang box on the vertical with a 2 gang switch would far outlive a single gang switch/ box.

Stoner

Armchair Andy wrote:

Does the proximity of the backing box (steel more so than dry lining) bear any difference to the lifetime of one of these switches? (Heat wise). I'm sure a 2 gang box on the vertical with a 2 gang switch would far outlive a single gang switch/ box.

It's more heat caused by poor connections rather than an inability for standard heat dissipation

Steve

P_1 wrote: »

Well the wiring on the back was a burnt mess but it's been fixed.

That would worry me.

It would suggest it's not a mechanical failure but a poor connection.

Did you fix it yourself or get a sparks? I would have asked them to spot check various other connections around the house as the original guys who wired it may have been less than diligent.

2011

Steve wrote: »

That would worry me.

It would suggest it's not a mechanical failure but a poor connection.

I have seen this quite a few times.
When there is a high resistance on a cable with a large current flowing through it the heat can travel up the cable and cause the insulation to melt and blacken on the cable like this.

Steve

2011 wrote: »

I have seen this quite a few times.
When there is a high resistance on a cable with a large current flowing through it the heat can travel up the cable and cause the insulation to melt and blacken on the cable like this.

I've seen commercial switchrooms burn down because of issues like this, improperly tightened connects are lethal.

In the one I saw, it was due to builders using a kango a few feet away digging a trench, the board wasn't checked after the works were completed and a 250A S/F went up.

That's why I'd be worried and if it was my house, I's be going around checking all nearby connections.