Katana

Open up a plug. I think its 15 Amps.

Luke

use a 13 amp

MattN

wrong size (and 13 amp).

alcazar

iTrader: (2)

WHERE is this fuse? Are you in the UK?
If so, 15 amp fuse wire is available from most DIY stores.
Or you could convert the fuse carrier to a miniature circuit breaker, (mcb), at 16 amps which will be even better.
THEN you need to know why the fuse went in the first place. Is it an immersion heater? You can change it yourself, but you'll need an immersion heater spanner to remove/tighten. They are about £5 from builder's merchants.
Alcazar

mj

before you go upping the fuse size, establish the size of the cable to the boiler. if its 1.5mm sq 16A fusewire is a bit much, if its 2.5 your'e ok.

also, the fuse has blown for a reason,there is more than likely a dead short or earth fault somewhere on the boiler or the supply cable to it - this will continue to blow fuses whatever size.

my advice would be to disconnect the boiler from the mains supply, and get a spark in to do an insulation resitance test on the cable. be careful though, if there are any elctronic controllers/stats etc in the cuircuit, 500v from an IR tester will damage the internal components.

what type of cable supplies the boiler? is it grey twin and earth or something older?

MattN

the fuse in in the fuse box.

I found a place called farnells that can do them. Yes it is an immersion heater, but there are two and I don't know which one is knackered, so I might just change both. Is it easy?

Dirty_Den

If you have to take the old immersion heater element out and put a new one in, be very careful when doing so. The tank inside the jacket is likely to be a copper one and will crease very easily! Don't be too violent with it....

Den

p.s. I had this happen about a year ago, the element had cracked, had to replace the immersion heater element. The element going had caused the fuse to trip out. You can get long life elements that are apparently less likely to scale up with limescale.

alcazar

iTrader: (2)

It's not too difficult. You'll need to turn off the main water supply, or the supply to the header tank in the loft(???probably???). When I did mine, I did both of those, and tied the ball valve in the header tank in the closed position using a piece of garden cane and string.
Then let water out of the hot tank by having someone turn on a hot tap, while watching the level in the header tank. Do this until the level drops to the bottom of the tank, then allow it to run for a further 30 seconds or so, to get it below the top of your hot tank, where the immersion is.
Switch off immersion heater, and disconnect from supply-usually done iside a cover at the top.
Using whatever spanner you bought/had/now have, unscrew immersion heater, and replace with new one. When I did mine, I took the old one to the plumber's merchants, and they swopped it for a correctly sized one: they vary in length, power etc. Have cloths/old towels/a bucket available at this point to mop up any spills...there are always drips especially if you have to run and find a cloth!!
Replace, with a smear of "Boss Blue" or similar on the mating surfaces -again, plumber's merchants will advise.
Reconnect, switch on cold supplies, and away you go.
About an hour's job, including waiting for it to drain down/refill.
Alcazar
PS: might be worth cleaning out any sediment in the header tank at the same time, depending on how old your house is. Did mine with a bucket of hot water, and a cloth. try to get as little as pssible down the outlet.

MattN

I'll give it a go, but I have two immersion heaters, one at the top and one at the bottom of the tank, so I guess I'll have to comepetely drain both hot and cold water tanks.

MattN

ARRRRGHHHHHHH, new years day and I had no hot water.

No idea whats wrong but I know the fuses have gone, all I want to do is replace them before calling out a plummer who will no doubt bend me over and...

But no where seems to have any 15 Amp fuse. Anybody know I can get some on line???

[Edited by MattN - 1/2/2003 7:33:42 PM]