Fused Spur Melted

[sammmo]

I have a 3.4 kw night storage heater which is connected to the economy seven via a 13A fused spur a couple of years ago, overnight after we switched the unit on in the autumn this fused spur melted and blew the fuse not in the spur but in the fuse box. my friend who is an electrician said i could have had a loose connection which was vibrating and creating heat. so i went to home base bought a new fused spur and fitted it making sure the wires were tightly secured. no more problems. turned unit off in the spring. my wife was feeling cold the other night so i switched the unit back on and during the night the fused spur melted again and it blew the fuse again in the fuse box. what can be causing this? suely i shouldnt have to tighten the wires every year. could it be a faulty/cheap fused spur problem if so which ones are the best make? all help appreciated.

[TheChair]

According to my calculator, 3.4KW at 240 volts is 14 Amps.

[bhg481]

3.4kw takes more than 13amps.

[The Builder]

The melting is usually down to using a cheap fitting, Sam. One of the better makes can handle this. I've seen plenty of ordinary double sockets with scorch marks too.

You could try an industrial 16 amp fused spur. That would handle the current easily.

Or ........... Assuming you have at least a 1.5mm flex from the heater AND no more than a 16 or 20 amp breaker in the consumer unit, then you really don't need the fuse. Simply use a 20 amp double pole switch.

[The Builder]

Sorry, that should read ...........

/// no LESS than a 16 or 20 amp breaker ///

[The Builder]

OMG ................ disregard that second post. I was right the first time .......... it's been a long day.