Retention Heaters - Single Supply, Dual Supply, What do I need to do?!

WiserMiser

As others have said, all that matters is what your meter is doing. If you rely on what you read or are told, it could be a very expensive mistake. You need to check when the meter on the wall switches over late in the evening, and then check that it switches back again exactly seven hours later. If it doesn't, check two hours later later still – it probably means cheap rate kicks in around midnight for two hours, changes to peak rate for the next two hours before finally coming back with five hours cheap rate.

So you can often get away with a single 24h supply to each heater, but woe betide you if you get anything wrong, e.g. if the real times aren't what you think they are, or if you make a hash of the programming. You also need to check what happens with GMT/BST: in the days of clockwork timers the E7 times stayed GMT all year round but that may not necessarily be the case with some smart meters.

It's a good idea to make sure one outlet has a neon indicator so that you can see at a glance when it's cheap rate.

Scot_39

Be careful what terminology you use - night storage heaters have been around for a long time - but any new fall into two broad catagories modern Euro Lot 20 regulated heaters - and High Heat Retention (HHR) NSH - that are insultated and tested for a higher degree of heat retention.

Presumably EOn fitted a 5 port meter - given you can have restricted. Model ?

For single wired heaters

So far only the top end HHRs tend to support it (lower priced lot20 from same manufacturers when looked in past dont) - and they can be at a signigifciant price premium (£100s at top end)

And in some applications e.g. halls or rooms not in use much - cheaper dual wired lot 20 - might be a worth while saving heater wise. Certainly gives options.

Bit if relying on own timers to match rate deals - and want to squeeze every last minute out of devices during the off peak using own timers - it's important you know exactly when your tariff changes - summer and winter.

Timing

I'd ignore on line regional tables - as above their often more wrong than right.

Your supplier might tell you your E7 meter nominals - when it roughly switches heaters via ALCS / and tariff to off peak say at midnight 00:00 to 0700 GMT (others are available - 0030 0730 GMT etc).

But if your meter has a non zero ALCS randomization offset set (once, at install time in seconds iirc) - and in your own meters case say, for example it was set to 8 min - it will switch that 8m later.

Both tariff if E7 style twin register based and ALCS restricted power - actually switch at 00:08 to 07:08 GMT.

And of course on your watch / clocks etc in summer time - thats - 01:08 to 08:08 DST.

A mechanical timer normally stays OK - a digital one - might need reprogramming summer and winter - some HHRs may have a seasonal switch block built in - as traditional E7 meters stayed GMT.

So non ALCS should follow your actual switch times - including the 08 min offset.

For dual wired heaters with restriced and live - timing all in the meter

With heaters like Quantums - you dont touch the charge timing. I think Elnur ECombiHHR will operate - despite older manuals suggesting you had to program timers. Users will confirm the latter.

But the key is for standard use the meter should keep tariff and ALCS load activation the same - the random offset applies to both - so they remain in sync.

Newer tariff for NSH - Snug from Octopus - strictly needs dual wired / restricted use

Dual wired also gives access to a new NSH tariff you may not have hear ofd - Snug from Octopus

When last checked its off peak 9p and peak rates ?? were both cheaper than E7 for my region.

There are a few Snug users here who are really happy with it.

It gives at least 6 hrs overnight (often more), 1 hour afternoon (which older heaters arguably would benefit more from than HHR) and an off peak rate of 9p. Which is for many maybe cheaper than E7 overall.

solomonkain

Just to check, is it a set it once and I should be fine? Or check every few days, weeks, months,years?

Swipe

Once it is set it should be good to go. Just make sure that the timer settings are saved when powered off, especially for longer periods over the warmer months and that the heater's clock keeps accurate time. You can monitor the daily cost and overnight kWh usage via your smart meter's in home display device (IHD).