Fuse blowing on Storage Heater

[Maydup]

I have storage heaters running on economy 10 and when I put them on for the first time this autumn the fuse blew in the wall sockets on two of them.
We replaced the fuses for new ones, but now one of these has blown again. Also the red indicator light on the switch is flickering when on.
What would be causing the fuses to blow?

[buildersmate]

Fuses blow because the device is drawing more electric current than it is supposed to be doing.
Rather difficult to say why, but possibly a partial short-circuit in the heating element inside.
Requires an electrician or similar knowledgeable person to investigate with the meter.

[Maydup]

Hello Doc
Thanks for your reply. I replaced the fuses with the same size fuses that were in them. 13 amp. But I don't know for sure the wattage. I think they're 3kw. does that sound right?

[Maydup]

Thanks buildersmate
Just as I thought - I need a person who knows about these things. I'll see how this new fuse goes and then call in a pro.
Sounds daft, but could my fuses be duff? I've had them in the back of the cupboard for years but assumed nothing much can go wrong with them.

[Disco Fever]

Some large storage heaters can be 3400 watts which is nearly 15 amps so the spur units you have will have to be changed for 20amp DP switches and then the fuse/MCB at the other end will have to be at least 16 amps....

[Maydup]

Thanks disco
Although I'm not sure of the wattage, they were installed by a qualified electrician someyears ago now and have a dedicated consumer unit etc . They've been perfectly reliable all this time, so I think the blowing fuse is most likley to be a component rather than the wiring at this stage in their lives.
I think I'll get someone to check them out.