I'll try and figure that out by turning off stuff at the CU. But as a starter for 10, the feed seems to go into the first FCU, loop into the second and then go out again - so maybe not radial - or maybe feeding something else as well?. The cable runs under the floorboards so can't follow it.
Two immersion heaters with switched FCUs got very hot
- Thread starter pedr0
- Start date
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That's about all you can do - and when you find which MCB turns off the immersions, you'll need to disciover what else (if anything) also gets 'turned off'.
Fair enough. In that case, as you go on to say ....
Indeed, either of those. I suppose another (horrible!) possibility is that both the immersions (and probably something else as well) are all on a spur from a ring circuit - but that seems unlikely, and one would certainly hope that no-one would do anything that crazy!
Kind Regards, John
Thanks John, And just to check (now that more info has been teased out earlier in this thread) - is it still the case that these two immersions really shouldn't be switched on at the same time, and therefore best to be controlled by a dual immersion switch?
Anyone that actually sparks for a living knows you should not have an immersion on a 13a sfcu even if it works out at 12.6a load, as running it for the amount of time it takes to heat the water will cause the unit to get very hot and after a while will cause problems. Should be on its own dedicated 16a circuit with a 20a double pole isolation switch
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There's nothing wrong with having two immersions on at the same time (I occasionally do it) provided that the electricity supply to (the two of them) is adequate - which, in practice, would probably mean that the two immersions would either have to each be on different (16A) dedicated circuits from the CU (which is how mine are) or both being supplied by a single 32A (radial) circuit serving the immersions and little/nothing else.
Kind Regards, John
One would hope so. However, I very recently saw an EICR (undertaken by someone who 'sparks for a living') which gave a C3 to the absence of an FCU feeding an immersion! The 'excuse' (when challenged) was that the circuit was protected by a 20A MCB "which is far too big for an immersion". Needless to say, we're not going to use that guy again - but it does illustrate that not all people who 'spark for a living' are equal
Indeed. I think we've agreed on that.
Kind Regards, John
Indeed it is. Fortunately, it's not rocket science, just potentially tedious
Let us know what you discover.Kind Regards, John
Here's a different model than the OP's with what I would term a complete label:
as opposed to:
as opposed to:
I've been meaning to ask... you initially wrote ....
Kind Regards, John
If you have the cylinder on its side, where are you drawing the hot water from?
Kind Regards, John
Strangely, from one end. It's like a vertical cylinder, but placed on it's side (and designed to be like that, or so I was told by the installer). And from my little experience over the last couple of weeks, the 'sink' immersion heater really does only heat up a little bit of the tank, while the 'bath' immersion heater heats up a lot of water. Not sure how that works seeing they are at the same level, so convection presumably doesn't come into play.
That's what I suspected/feared, because it sounds like a very inefficient system.
If the hot water is being drawn from the centre of the 'side' (as installed), then about half of the heated water will nor be 'accessible' (i.e. will essentially be 'wasted', since it will just sit in the top half of the cylinder). Starting from cold, you would have to heat half of the water in the cylinder before any significant amount of hot water could be drawn out - and, even if it started off full of hot water, you would only be able to draw off about half of it before it 'went cold', half a cylinder's worth of heated water sitting above the draw-off point and 'inaccessible.
Sounds very strange!
Kind Regards, John
It doesn't seem to add up to me, do you have a photo?
Oh! My mistake. Hot water is not tapped from the end - it's taken from the actual top (i.e. the long edge of the cylinder) when the tank is lying down. Harry's request for photos forced me to crawl in there and take a better look.
Photos are poor because it's such a tight space.
One end
T'other end
Side (see it's even got some proper feet to sit on!)
The only pipes that are attached all enter/exit at the highest point.
The only marking I could see on the cylinder
The first two pipes
The other four (I think) pipes
Photos are poor because it's such a tight space.
One end
T'other end
Side (see it's even got some proper feet to sit on!)
The only pipes that are attached all enter/exit at the highest point.
The only marking I could see on the cylinder
The first two pipes
The other four (I think) pipes
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