Immersion Heater Wiring Question (E7)

jonnysarmbrace

Hello! First-time poster but long-time lurker...

I have an immersion heater in my all-electric flat and I'm wondering whether it's wired correctly. It is a Santon PremierPlus direct, unvented system which has 2 elements; one at the bottom and one half-way up.

Now currently, the element at the bottom is connected to the day-rate standard mains, and the middle element is connected to the E7 circuit.

Is this correct?

I'm sure that as the hot water outlet is at the top, that the middle element should be connected to the mains for the purpose of boosting, whereas the bottom element should be connected to E7 for the purpose of heating the entire system overnight using 'cheap' electric.

Any help would be appreciated!

Regards,
Tom

jalexa

jonnysarmbrace wrote: »

Now currently, the element at the bottom is connected to the day-rate standard mains, and the middle element is connected to the E7 circuit.

Is this correct?

No. Should be the other way round as you have correctly worked out. (but for safety's sake you are certain?)

Check here...
http://www.santon.co.uk/docs/PremierPlus_-_Issue_8_-_36005803.pdf

muckybutt

Bottom element should be E7

Top element should be day rate top up

jonnysarmbrace

Cheers guys.

As for the Santon guide, I'd read that before I asked on here and although it does mention that the middle element is the boost, it doesn't explicitly state how to wire it into an E7 system and that got me questioning my logic.

At least now I can rewire it with confidence that I'm right!

Any idea what the consequences of this incorrect wiring are, in terms of performance etc?

Pincher

Check out the 15min/30min/1hour/2hour boost button.

http://www.tlc-direct.co.uk/Main_Index/Water_Heating_Index/Immersion_Heater_Timers_2/index.html

It's really annoying to realise the boost button was on for days.
For an MSE, it's a sin.

jonnysarmbrace

Pincher wrote: »

Check out the 15min/30min/1hour/2hour boost button.


It's really annoying to realise the boost button was on for days.
For an MSE, it's a sin.

Well it seems I've had boost on since I moved in around August!

So does the above just replace the switch face-plate?

Also, when I unwired the 2 elements, it appears that the middle element was wired with the neutral and live the wrong-way round. I know it reverses polarity, but what the consequence of that is, I don't know...

jalexa

jonnysarmbrace wrote: »

Any idea what the consequences of this incorrect wiring are, in terms of performance etc?

Since you fortunately have a factory insulated cylinder probably less than you fear. The cylinder would be permanently fully heated to the cylinderstats limits mostly at day rates. Recharge after use would have mostly been at day rates, so your water heating costs will have been about double.

Any idea who was responsible for the original botched wiring?

macman

And how did you find out?

jonnysarmbrace

jalexa wrote: »

Since you fortunately have a factory insulated cylinder probably less than you fear. The cylinder would be permanently fully heated to the cylinderstats limits mostly at day rates. Recharge after use would have mostly been at day rates, so your water heating costs will have been about double.

Any idea who was responsible for the original botched wiring?

The flats are 5 years old so I imagine it's been there since then, and it's not really a surprise judging by some of the "workmanship" carried out at the behest of the landlord/letting agent.

As for the finding out, I'm quite an inquisitive chap and economy 7/immersion heating is totally new to me so there was lots to play with. Not to mention the urge to money-save!

macman

I wonder if the whole block is wired that way then-you could have the start of a nice little earner here...

Pincher

My own father was a wiring death trap, and he was a surgeon!
My plumber's assistant wired a low voltage DC programmer into a 230V circuit. What's the point of asking who did it? You execute one, there are ten million more.