Smart Meter, Economy 7 and changing to Dimplex Quantums

worlestone

I've a question for the clever E7/Dimplex Quantum bods here

We have a smart meter, see photo and Economy 7 with mostly older Dimplex storage heaters. We have one Quantum storage heater in the kitchen, bought as an experiment to see how we got on with it.  We like it and are thinking about replacing the other 4 storage heaters with Quantums.  However, to minimise the cost and rewiring think the single wiring option is needed for the remaining heaters. I think there's space on the unrestricted consumer unit which is next to the off peak consumer unit. Is this possible using out meter or am I missing something - from an electrically incompetent home owner... please reply in simple words

Thank you

Gerry1

TL;DR: You can do this, but you have to be (or become) an anorak.

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You can use a single supply but it's a bit of a high risk bodge.  Get it wrong or fail to spot a variance between the meter's actual switching times and what your Quantum is programmed to expect and you'll have sky high bills.

Don't rely on the installer to program it correctly.  He won't be there around midnight and at breakfast time to see the meter change over, and he won't pay the bills if he gets it wrong.

You'll have to find out exactly when your meter actually switches, not merely when it's supposed to.  Don't rely on what you're told on the phone or the web, look at the meter on the wall or the IHD for confirmation.  You'll also have to become familiar with programming the Quantum and telling it not to use the expensive daytime boost.  Again, don't rely on the installer.

If you go ahead, make sure one E7 wall outlet has a neon indicator you can see at a glance so that you'll soon notice any change in switching times.  Watch out for GMT/BST changes.

Scot_39

Yes - it's a 4 port with auxiliary contactor - so you can go either way.  

Just a personal observation - c4 years ago I got quote - from the guy doing my neighbors who no longer found the old models worked well after switching e10 split 3 times daily to e7 overnight.

The dual wired option - with separate new live lower power 24/7 second spur feeds tapped off of nearest ring main access - was not that much more expensive than re- configuring my 3 way split CU - £100 or so in total just a 2-3% of total c£3000 installed for 1 large and 2 medium older style non RF quantums

(Hallways had no / no suitable suitable 24/7 socket - drilling through to bedroom / kitchen - to get to ring main)

And many cheaper lot 20 require the dual wired mode anyway - there is no single supply mode - on say XLE slimline or sister co Creda TSRE - IIRC.  And if you don't actually need the quantum's HHR in some locations - you could save £100-200+ per heater on largest models . Like say hallways - where I use mine just for constant low background heating.

Sadly I chickened out - wish I hadn't now - as cannot buy new the non RF - but the suspected fault in one of the heaters - was actually an overheating MCB when drawing c16A of the 20A rating.

And just to add another point to Gerry1 - warning - don't forget the GMT/DST time shift impact potential - giving a full additional 1hr mismatch twice per year - in single wired mode.