AEG shower stopped working

[SteveK]

We've got an AEG electric shower. It's the kind that just senses when the tap is open and comes on. It's a white plastic box, next to it is a Thai style isolation switch, a Chang 30A safety breaker.

 

My first  thought was that a fuse must have blown, but there would not appear to be a fuse inside the shower. It doesn't appear to be sensing the flow of water wen the tap is opened, either that or it isn't getting power. Could the safety breaker have a fuse inside? It seems pretty small, and is wired into the mains so not sure about dismantling it because I don't know where the house fusebox is, if there even is one.

[Crossy]

OK, is the safety breaker turned on? Turn it off and back on.

 

Your heater probably has in internal RCD/ELCB device, look for a "reset" button.

 

If you're not sure what to look for, post a photo of the heater or it's model number.

 

You probably do want to find the incoming supply board so you know where to pull the power should you ever need to.

 

 

[SteveK]

I'm no electrician but I know that the breaker needs to be on to use the shower. The reset button does nothing because the shower doesn't come on. Its an AEG FM-35E.

[Crossy]

So, did you try turning the breaker off and back on? Some breakers can be tripped and the operating lever remain looking like they are on.

 

That heater has an electronic earth leakage unit, if pressing reset does nothing you probably require the services of an electrician.

 

Do you have any test equipment at all, multimeter even a neon screwdriver? You may be able to help your sparks by pointing him in the right direction.

 

The issue may be at the distribution board that feeds the safety breaker, you really do need to find it.

 

[SteveK]

I'm fairly certain that it is not detecting the flow of water, which is very decent, so is not switching on. I've found the flow detector by following the 2 wires from the circuitboard, but the detector which I presume is a microswitch setup of some sort, seems to be embedded in the pipe, not sue how to get at it.

[SteveK]

I shorted the contacts on the circuit board with a staple to trick it into thinking that water is flowing so that I then just use the breaker to turn the unit off and on, but no dice, no lights, no nothing. Could the Chang 30A safety breaker be at fault so that the shower is not getting power?

Edited May 28, 2019 by SteveK

[ExpatOilWorker]

Try turning the main breaker off, then reverse the water flow and flush the unit out for a couple of minutes. 

Connect the hoses the right way again, turn power on and give it a try.

Sometimes the pressure differential valve can be blocked. 

[SteveK]

Can't get the unit to power up at all, there is no blockage, water flows through the unit very well. I've determined by a process of elimination that any distribution board or box must be in the roof, there's no way in hell I'm going up there. Cold showers will be fine for a while I suppose. I am still very sceptical of the breaker because replacement ones in the local hardware store are about 50 baht!

[Crossy]

55 minutes ago, SteveK said:

I am still very sceptical of the breaker because replacement ones in the local hardware store are about 50 baht!

 

You really need to verify that the beast is getting power. If you don't have / can't get a multimeter you need to employ your local electrical man.

 

I certainly wouldn't be messing about inside the unit shorting random points (all that circuitry will likely be at mains voltage).

[SteveK]

43 minutes ago, Crossy said:

 

You really need to verify that the beast is getting power. If you don't have / can't get a multimeter you need to employ your local electrical man.

 

I certainly wouldn't be messing about inside the unit shorting random points (all that circuitry will likely be at mains voltage).

It's AC mains going into the unit, but all the circuity is obviously DC low voltage. You're right, though, I will try and find someone who can have a look at it, thanks for all the help.

[Crossy]

44 minutes ago, SteveK said:

but all the circuity is obviously DC low voltage.

 

This is an EXTREMELY dangerous assumption to make.

 

In order to save cost many appliances that don't have user accessible metalwork (headphone outlets and the like) and have modest power requirements use a very simple capacitive dropper circuit along with a bridge rectifier to create the low voltage DC needed for the electronics.

 

This means that most of the electronics is banging around near one or other mains pole, if it's the neutral you're probably going to be OK, if it's the live ...

 

Something like this but configured for 220V AC.

 

[ThaidDown]

Quote

but all the circuity is obviously DC low voltage

They engrave that on peoples tombstones !

 

[SteveK]

I've been shocked my mains voltage many, many times in my life, first time was at age 5, I was hospitalised and still got the scars on my hands to remind me. Probably explains my erratic behaviour.

 

Had a few big shocks in Thailand too (I have also been electrocuted here). You guys are definitely right, I will be more careful, so will get someone in who knows what he's doing (easier said than done in a tiny village). It would seem remarkably dumb to end up dying trying to get a hot shower when it's 35 degrees outside.

 

I'm sure we used to call those circuits "rectifiers" when I was a schoolboy, could be wrong though.

Edited May 28, 2019 by SteveK

[Crossy]

6 minutes ago, SteveK said:

I have also been electrocuted here

 

Semantics I know, but if you have been electrocuted you are dead. https://en.wikipedia.org/wiki/Electrocution

 

Please take care, electricity and water are not things to fool around with together.

 

There is really nothing to stop you doing some self-diagnosis with a simple multimeter (a few hundred Baht from Tesco), simply measuring the voltage at the heater terminals will get you a long way to determining where the problem lies.

 

[SteveK]

I've got a multimeter somewhere, but suspect it's at the bottom of a big box full of junk.

[farmerjo]

Are you sure the pressure of the water hasn't changed?

Cleaned the thimble.

Try it with another tap on as well.

Edited May 29, 2019 by farmerjo

[SteveK]

The water pressure is absolutely fine, it would appear that there is no power arriving at the shower. I bypassed the flow sensor, and it still doesn't come on. I've looked very carefully at the internals of the shower, there appears to be no scorch marks, no fuse to replace, so am assuming that the fault is external to the shower unit, either at the breaker, or at the distribution board in the roof. Is it possible that a rodent could have chewed through a wire in the roof?

Edited May 29, 2019 by SteveK

[sometimewoodworker]

5 hours ago, SteveK said:

Is it possible that a rodent could have chewed through a wire in the roof?

Yes

[Crossy]

You really need to find your meter and actually verify that there's no power getting to the unit.

 

Without some actual measurements it's all just guesswork and guessing where electricity is concerned is, shall we say, unwise.