off peak immersion problems

[hairy g string]

hi .customer complained that her off peak water wasn't heating.its a ex b7 controler .boost worked fine on 24 supply.there is just 1 cable going to tank [1 elememnt] but off peak trips old wylex 15a push button mcb
sorry dont no the bs number.changed the b7 controller because it was 25 years old anyway.the off peak came on to give her a full tank of hot water and then next day trips.never tested element or cable because the boost works fine on a mem 16 a mcb.i am going to put in a 2 way consumer unit tomorrow for off peak.
surely it has to be that pop mcb that is faulty.has anyone else came across similar scenarios .thanks

 

[Octopus]

Me thinks this thread needs to be restarted with more detail and more facts.

 

[7029 dave]

Sorry but my thinking is, if you have off peak IH, then there must be 2 elements end of.

 

[davesparks]

Sorry but my thinking is, if you have off peak IH, then there must be 2 elements end of.

Why must there be? Boost controllers which swap the one element over onto a 24hr supply for boost are available.

There's a whole block of flats in woking with exactly that setup.

 

[7029 dave]

Boost is just that, it is not true 24hr, unless there is 2 flexes into the one element which I very much doubt.

 

[Dave OCD]

Boost controllers have a single 24 hour supply [otherwise the clock would lose around 17 hours a day although I realise they have either a 'spring reserve' or back up battery in the case of digital units ].
It's just synchronised with the E7 meter to coincide with the off peak tariff and the 'boost' is simply activating the output manually usually counting down to 'off' in an hour at any time it may be required. Usually the ones I've installed have two flexes out though, the bottom element on the tank being the E7 and top being the boost.
There has to be something missing from the description of the problem here....

 

[davesparks]

Boost is just that, it is not true 24hr, unless there is 2 flexes into the one element which I very much doubt.

It can't be a boost without a 24hr supply!

 

[7029 dave]

It can, some off peak E7 meters have the boost button, other than having 24hr supply, whitch would be 2 elements day and night.

 

[Resu]

E7BX can be used to control tanks with one or two elements.

 

[7029 dave]

E7BX can be used to control tanks with one or two elements.

Dedicated off peak board, IH on that dis board, one element one flex to it, how is that gonnar be 24hr.?

 

[Resu]

Dedicated off peak board, IH on that dis board, one element one flex to it, how is that gonnar be 24hr.?

24hr feed and off peak feed into E7BX, one sw out to element...

 

[Dave OCD]

Why must there be? Boost controllers which swap the one element over onto a 24hr supply for boost are available.

There's a whole block of flats in woking with exactly that setup.

Must be a bloody big cylinder and a heck of an element in it.

 

[Resu]

 

[hairy g string]

no 1element 1 flex.a spare cable run up to tank for a top boost but not being used ie no top immersion .e7bx mi comes with wiring diagram with for duel or single element.will test element tomorrow and see what comes with that results.

 

[7029 dave]

24hr feed and off peak feed into E7BX, one sw out to element...

That set up is not the norm, because that totally defeats the object of an off peak consumer unit.

 

[Resu]

It was the norm for hundreds of small properties up here in the past. Water heated by offpeak supply with the option of a boost at any point. Typically fitted to small tanks with top entry element.