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

 

[davesparks]

Is a dual element immersion heater?

Why do you want to fit a new CU when you could just replace the mcb which you seem to think is faulty?

And why did you replace the controller just because it was old?

 

[hairy g string]

its a single element.timer plugs were brittle inside and discoulered around double pole switch for timer.the wylex mcb will hold for an hour or so and then pop.its a rented flat so land lord agreed to change timer.can you still get that type of mcb apart from ebay.trouble is tennent is complaining on cost of using boost

 

[davesparks]

The replacement for that mcb is a current item yes, I'd expect any wholesaler to have them on the shelf.
You may have to change the base too but that comes with the mcb so shouldn't be a problem.

Even screwfix sell them! http://m.NoLinkingToThis/p/wylex-16a-sp-type-b-curve-mcb/34544

Why didn't you test the element?

 

[hairy g string]

didnt test element because the 16amp type b 60898 works fine on the boost.its the same element for both mcb

 

[Pete999]

Why can't we say what we think any more

 

[davesparks]

didnt test element because the 16amp type b 60898 works fine on the boost.its the same element for both mcb

How do you know that mcb is working correctly?

I can't see the logic in not doing a couple of tests which would take a couple of minutes to confirm the element is ok in favour of randomly changing parts and expecting a bunch of strangers online to help.

 

[davesparks]

Why can't we say what we think any more

You can, you just have to think about the exact wording a bit more!

 

[hairy g string]

point taken

 

[davesparks]

This might be a daft question, but you do know how to test an I/H element don't you?

 

[Octopus]

Is it me or am I being thick.

There's 1 cable going to a single element, which works OK on boost but not off peak?

Puzzled!

 

[Deleted member 9648]

This has all the signs of a classic in the making.

 

[davesparks]

Is it me or am I being thick.

There's 1 cable going to a single element, which works OK on boost but not off peak?

Puzzled!

It sounds like it. With a boost controller to swap it onto the 24hr supply for the boost.

So it has a 24hr supply from a 60898 16A and an off peak supply from a 3871 15A
The 24hr works but the off peak trips after ~1hr
The element is untested.
So we could have a worn out 3871, or a faulty 60898, or an element just starting to break down. Or any combination of the above

Plus we have an OP who has fitted a new boost controller and now wants to rip the customer off for a new CU just in case that fixed it. Oh yeah, he hasn't tested the element either for unspecified reasons.

I'm only assuming he has actually looked inside the cap of the I/H and confirmed it's a single element. It may yet turn out to be dual element and a 4 core cable!

 

[davesparks]

This has all the signs of a classic in the making.

Step into my web said the spider to the fly!

[emoji12][emoji106]

 

[Pete999]

Hey Luv have we got any more of the red stuff? I need a refil my brain hurts