Recurring electric shower fuse problem – burnt fuse holder

Hi all this is my first post, I’d really like some help regarding an recurring issue with my electric shower. Apologies in advance for my lack of correct terminology.

I have a 9-10 year old Gainsborough electric shower, quite low power (6.9kw I think) with an isolation switch (pull cord) in the bathroom. This morning whilst showering it suddenly stopped working and the LED on the isolation switch also switched off (good thing I’d just finished rinsing the shampoo! ).
This had happened before, so I checked the shower fuse in the mains box, the fuse did not look popped or burnt but the top half of the Wylex fuse holder has totally burnt through, although some of this damage may have been from the last time it happened! This has happened before probably 3-4 times but very intermittently. I think on most of these occasions the fuse holder has been burnt with minimal visible damage to the actual fuse. Could this be due to overloading?

My mains box (Consumer Unit) is the old fashioned type (sorry didn’t make note of the model) and uses the old type HRC fuses held within brown cartridges with the two prongs (made by Wylex model M28/3)

As I was saying his has happened before a few times in the past, it seems to be very intermittent, I think the last time it happened was maybe 10-12 months ago, I cant be sure. But I do remember it happened couple of times within the space of a few days, I simply replaced the fuse & the holder (i think) and then it was fine for months on end.

For info the shower was on the high pressure setting when it switched off.

The following thread is very similar to my problem:

//www.diynot.com/forums/viewtopic.php?t=76963&highlight=burnt+burned+burning

Can anyone recommend a reason and a solution for this, and if an electrician is required can someone suggest reliable electrician in the Leicester area to investigate?

Thanks in advance

sounds like overload

presumably you are using 30Amp fusewire in a fuseholder with red dots.

it would be good if you can check the real power rating of your shower

Is the Wylex Brown or Cream? Can you post a photo of it?

It is likely that the circuit wires, where they are clamped into the terminal at the top of the fuse, have overheated. Once this has happened the copper wire is softened, and it never makes a good connection again. it comes loose, causing a poor connection and more overheating. this happens again and again and keeps getting worse. At the very least you need to have the connection remade with new wire, but in view of the age of the installation it would be far preferable to have a new modern consumer unit fitted which is built to carry these large loads, and can be fitted with an RCD which gives some protection from electric shock (very important with an electric shower). This is not a DIY job. the shower cable may also need to be replaced. Then you would have the capacity for a more powerful electric shower in future (your old Wylex is not capable of supplying a modern electric shower in safety).

If the fuse holder shows any signs of having burnt then there was an overload. Even scorching is a sign of serious and dangerous overload.

The heat from the previous overload(s) will have affected the metal contacts in the fuse holder and made the connection less than it should be.

It may have affected adajcent fuse holders.

The burnt fuse holder and maybe the whole consumer unit must be replaced and that is a job for a skilled electrician. A photo of the damage would help to advise which.

In the meantime do NOT use the shower as the risk of fire from the burning fuse is not small.

Thanks for your replies, the wylex fuse holder is brown in colour, it may have had the red dots on it but i cannot see them now it they are located on the top half of the holder.
JohnD i not sure what you mean by fusewire in this context as it doesnt use fusewire as such but HRC type fuses, here is a link from maplins to show you what i mean:

http://www.maplin.co.uk/Module.aspx?ModuleNo=18113&criteria=fuse&doy=22m11

And here is a link to a picture of what the wylex fuse hoolder looks like

http://www.rock-electronics.co.uk/c...d=321&osCsid=1162e18f3e275295ba35471655bb06ab


I will try to upload a picture of my burnt out one when i get home tonight.

So is there nothing i can do in the meantime? And how much would fitting a new CU cost typically? both for the installation and the unit itself?

I can confirm (99%) that my wylex fuse holders do NOT have the dots on them.

Here is another link to show what i mean:

http://cgi.ebay.co.uk/Wylex-Wireabl...ryZ26215QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Yes, the ones in the pic are what i was thinking of, and they all have dots on them.

Just wanted to ask again if there is anything i can do in the meantime? Would a new fuse holder & fuse be worth trying? And how much would fitting a new CU cost typically?
thanks

The contacts in the fuse box are probably very worn and have lost their spring against the fuse prongs. DO NOT reconnect that shower to that fuse box.