Timerswitch before, or after fuse, & then immersion heat

[rds45]

Hi, I'm on an electric hot water system with immersion heater. There are two elements in the hot water tank, the top one is no longer used. The top one was previously connected to the peak time electric so you can turn it on as a booster when you want. The bottom one was previously connected to the Economy 7 electric working during the night.

I had the bottom immersion heater changed about five yrs ago. To save money the plumber disconnected the top element and put the bottom element onto the peak time switch so I could just have it on when I wanted to suit my needs. I'm happy with this.

However, sometimes I would forget to switch it off and go to work, so to remedy I added a timerswitch to the circuit. So, at the moment, electricy feds into an electric switch with a 13a fuse in it in the hot water cupboard, which then goes to a timerswitch, and then goes to the hot water element.

The problem is, about every 18 months or so the timerswitch blows so the hot water stops working. The third one has just blown again, when I bypass it the hot water element starts working again so the main circuit board has not tripped out, its just blown the timerswitch again.

So question is does it matter where in the line I have put the timerswitch? In other words should I move the timerswitch before the peak time electric switch with 13a fuse in it, and then connect that directly to the hot water element...or will this make no difference and still keep blowing the timerswitch periodically? If the system overloads I want the 13a fuse to blow instead of the timerswitch?

Look forward to advice thanks.

 

[holmslaw]

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[Iggifer]

or use one of these

http://www.tlc-direct.co.uk/Products/SMTGBT5.html

 

[riveralt]

You will need something like this:

http://www.screwfix.com/p/lap-mechanical-24-hour-immersion-timer-240v/91462
or
http://www.tlc-direct.co.uk/Products/TCTI24.html
But as Holmslaw states you will need to hard wire it into the circuit - are you up to that?

 

[EFLImpudence]

But as Holmslaw states you will need to hard wire it into the circuit - are you up to that?

OP does not mention a plug in timer but if it is he must have fitted the socket.

So question is does it matter where in the line I have put the timerswitch?

As has been said, it will make no difference but after the switch is more sensible so you can switch it off easily.

In other words should I move the timerswitch before the peak time electric switch with 13a fuse in it, and then connect that directly to the hot water element...or will this make no difference and still keep blowing the timerswitch periodically?

No point.

If the system overloads

It can't overload - assuming the immersion is the only load on the circuit.

I want the 13a fuse to blow instead of the timerswitch?

It won't.

If the circuit is from a fuse or MCB which is correct for the cable then the 13A fuse is not necessary anyway.

 

[kai]

Buy yourself a Good Quality Immersion Timer (Horstmann comes to mind) - they cost around sixty pounds each (the price of three basic timers), but have heavy duty mechanics, suited to daily operation.
Wire it between the 13amp FCU, and the immersion element, the Horstmann has cord clamps for both flex inlet and outlet integrated into it.

 

[holmslaw]

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