Dual immersion boost switch

Drakon

Registered User
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851
Hi,

I've done some searching and this question has come up a few times before,
and has been largely unanswered. Those posts were a few years back so I'm
hoping the switch I'm looking for has been made by now.

I currently have a typical immersion switch, i.e. it has two stiches: "On/Off" & "Bath/Sink".

I want to replace this with a dual immersion boost switch,
something like this...
https://www.electricalworld.com/en/...ter-2-Hour-Electronic-Boost-Timer/m-3904.aspx?
... but with a "Bath/Sink" switch on it too.

My previous house had two one these, one labelled Bath and the other labelled Sink.
Another solution may be to take my current switch, disable the "On/Off" switch
and connect this boost switch to it.

But I was wondering if any members know of a one unit solution?

BTW, I'm aware that there are a plethora of two channel electron timer out there.
But we have no need for a timer on the immersion. We just switch it on as required,
then switch it off when we remember to do so. The TimeGuard Boost switch is so simple
it would be perfect if there was just a Bath/Sink switch on it.
 
Was getting some plumbing done on a new house recently and the plumber noticed that the 'Sink' and 'Bath' were two separate switches on the immersion. He said this was very wrong as the sink and bath are two different heating coils in the tank and it should never be possible to switch them both on together for fear of overloading the circuit. This would imply the sink/bath switch is normally a dual dipole switch connected in series after the On/Off switch, to switch two separate circuits. So it makes sense to me that your timer switch would only replace the on/off, and just keep the existing sink/bath switch. I am not an electrician, so best to get advice from someone who knows what they are talking about.
 
More or less there @dub_nerd , The on/off is used as a single one way switch(usually Bi-pole) which then feeds the bath/sink switch which is a two way switch. ie. If A=supply then it can feed B (sink) or C (bath) but as you correctly say not both together.

So to answer the OPs question you only need to time/control the on/off switch and basically that is all the linked to "timer" does as it replaces this switch.
 
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That makes complete sense. Not sure what my previous plumber was up to, but he's pretty good and can explain things very clearly, so maybe he'd it set up in a way that only one can work at a time.
 
We use a time switch which is first in line. It has three positions ;

POSITION 1 = Off.
POSITION 2 = On at time(s) programmed.
POSITION 3 = On by manual override. Current stays on while this position is selected.

The time switch output feeds a single box with two switches ;

SWITCH 1 = On or Off. This governs current to SWITCH 2.
SWITCH 2 = Bath or Sink.

If you want to just turn on the immersion select POSITION 3 of the time switch and Bath or Sink.

Like dub-nerd, I do not think that it is supposed to be possible to operate both sink and bath simultaneously. BTW it was not unusual in some older houses from the 1960s to have separate switches for the bath and the sink whereby they could both be on together - that arrangement might heat more than the water.....

OP I would advise you very strongly not to make any alterations or adaptations that takes switchgear outside the normal parameters within which it was originally designed. I am not sure but newer electrical regulations might actually prohibit certain electrical work being done if you are not an electrician. If you are making a change get an electrician to advise you and to do the work.
 
Like dub-nerd, I do not think that it is supposed to be possible to operate both sink and bath simultaneously.

That's correct, both sink and bath elements are rated at 2.7-3kW, having both on together would overload the circuit.

I am not sure but newer electrical regulations might actually prohibit certain electrical work being done if you are not an electrician. If you are making a change get an electrician to advise you and to do the work.

This is detailed in the Electricity Regulation Act 1999 (Restricted Electrical Works) Regulations 2013. Replacement of switches such as the suggestions here is still permitted, but especially given the high current these circuits draw, anyone not 100% confident in what they are doing should employ a qualified electrician.
 
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