Faulty immersion heaters or timer?

[alick8]

Please can somebody help:
about six months ago I replaced my hot water tank, immersion heaters(heatre 11" gold dot combined thermostat) and timer(Hortsmann Quartz economy seven) as the previous ones were very old and i had just moved in. the wiring to the fuse box is the original and it has its own fuse.
All worked well but in the last month the fuse has tripped during the night. So i have used the boost when needed hot water.
Now when I un trip the fuse and switch on to timed (even with no boost and not in the middle of the night so the econ 7 should not be on either)there is a big blue flash from the timer box and a large bang.
Nothing has changed with wiring so is it a timer problem or immersion or something else.
Someone said in could be immersion and limescale but they are not that old

Thanks in advance

 

[breezer]

i would say both need changing, a big blue flash indicates something went wrong, probably the heater, but in doing so would have not done the timer any good either, hance replace both

 

[GasMan1965]

i would say both need changing, a big blue flash indicates something went wrong, probably the heater, but in doing so would have not done the timer any good either, hance replace both

I agree with my Neighbor

 

[alick8]

thanks for the reply
any idea why they would have gone wrong as they are pretty new?

cheers

 

[GasMan1965]

Probably the element has rotted !!