Single supply Economy 7 Storage Heaters?

Stubod

Hi all and thanks for all the feedback. I can confirm that I was only looking to rune the "24hr" supply from an adjacent socket as (I think) this just powers the timers and display. The "main" power to the actual heating elements will still come from the separate ET supply/fusebox.

I think the problem with the one heater is a breakdown of the insulation. It still gets plenty hot enough, it's just that the heat has "run out" by the afternoon, where as the "newer" heater we reaplaced a good few years ago is remains worn until well into the evening.

Thanks for the E-bay tip...I will have a look!

EssexHebridean

Gerry1 said:

ngr49er said:

Gerry1 said:

If your 'old and cold' NSH used to work OK it may just need a failed element to be replaced.  That's cheap and easy.

To check, when E7 kicks in around midnight set the input control to maximum and turn everything else off.  Count the number of impulses (flashes) per minute on the meter's metrology light.

For example, if it's marked 1000 imp/kWh and there are 40 flashes/min then it's drawing 2.4kW.  If it's a 3.6kW NSH then it's likely that it has three elements but one has failed.

Of course, a new HHR NSH will be cheaper to run because it won't waste so much heat during the night when it's not needed, but they're not cheap.

Not sure that @ngr49er is correct about the top-up (balancing) element.  IF correctly dimensioned and programmed it should seldom need to be used, just as well because peak E7 is so expensive.

But my understanding is that with the maximum top-up time set to zero you shouldn't need to change the charge rate daily, you just tell it the temperatures you want and at which times and it does the rest.  If there's a sudden cold snap you can always turn on the boost manually.

The way I understand the Elnur's, is if the daytime rate balancing element is set to 0 hours, then what ever overnight charge % you have the unit set to, it will never adjust automatically. You have to set the balancing element to at least 1 hour, for the overnight charge % to change automatically. At least that is what the manual says and I admit that I have so far always had the balancing element set to at least 1 hour.

I'm guessing because I've never had a HHR NSH, but the balancing element figure is probably just the maximum allowed if it runs out of stored charge.  Perhaps they're being cautious to avoid complaints along the lines of 'we spent our live savings on shiny new heaters but we're still cold in the evening'.

Having to top up with peak rate electricity every day can't be the usual modus operandi, it defeats the point of NSHs.  It should be much more of 'break glass for emergency exit' feature. @EssexHebridean may be able to advise.

I think we’ve established in the fairly recent past on here that the Elnur Combi NSH’s do pretty much have to use the balancing element - we’ve had a few threads on them over this past winter. 

I’ve got a Dimplex Quantum which is dual wired - it was a pretty simple job for our sparky to run a spur for the 24 hr supply and thankfully while the Quantum does have a boost element it’s not necessary to use this unless for any reason you get caught out with insufficient charge (for example a sudden unforcasted temperature drop, or just needing a higher temperature than the charge allows for.  Personally from what Inhave read about the Elnur units, I wouldn’t be inclined to forget them. 

There is a seemingly “halfway house” solution these days made by Creda I believe - it’s not technically a HHR model but does seem to have some of the same qualities. Details here: https://www.credaheating.co.uk/storage-heaters 

littleteapot

EssexHebridean said:

There is a seemingly “halfway house” solution these days made by Creda I believe - it’s not technically a HHR model but does seem to have some of the same qualities. Details here: https://www.credaheating.co.uk/storage-heaters 

Yes I've looked at the Creda TSRE a few times and they look a good compromise for the price. Not heard anyone say anything bad about them yet either. I still believe Dimplex Quantum are the panacea of NSH, but the cost difference wouldn't justify it for me.

In terms of aesthetics, the old Dimplex Duoheat are the best looking NSH I have ever seen. They are now an obsolete model but we still have two downstairs and are very happy with them given that wife and infant/toddler are home all day so the constant release of heat is no problem. But they stay warm enough even in the evening without boost (radiant front panel) ever being on so I see no benefit to replacing them yet. After 10 years I did have to replace the control module in the bottom though as it stopped working, but this was about £70 part on ebay. Dimplex storage heater duoheat, no heat! | DIYnot Forums

Gerry1

I'm surprised that Dimplex haven't gone for a simple Boost button that switches on the peak rate element for an hour.  It could be illuminated in orange if the room falls below the target temperature, and show red when the element is in use.

Cheap immersion heater timers often have a Boost knob, so there's no reason why a costly HHR NSH shouldn't have something similar.

Some E7 meters also have a Boost button that livens up the E7 switched circuits for an hour (but at peak rate). It should be a standard feature.

Stubod

..yes but for a "boost" button to work they would need a "high power" 24hr supply?

Gerry1

Stubod said:

..yes but for a "boost" button to work they would need a "high power" 24hr supply?

They always need a 24h fused spur supply.

EssexHebridean

You can boost the Quantums if needed - there are various time options available. 

Scot_39

Stubod said:

..yes but for a "boost" button to work they would need a "high power" 24hr supply?

The boost element in the Quantums - like the Elnur ECombi HHR etc - is much lower powered than the main charge elements.

In the biggest Quantum - the 150 - which is a 3.3 kW main element charge rating - the boost element - is c1/1.1kW.

Quantum call it boost element, Elnur balancing element etc. iirc

So essentially like switching in a £20-30 plug in fan heater - on 1kW setting. 

Whilst the main charge circuit for all (even the lower rated ones iirc) has to be wired back to a dedicated 20A MCB in the consumer unit on a new install, perhaps the day supply can simply be spurred off the ring main - e.g. from behind a local 13A socket.

But perhaps an owner / upgrader like @EssexHebridean can confirm this.

EssexHebridean

Pretty sure our 24hr supply did indeed just get spurred straight off the ring main.

I actually ran the boost element on our Quantum last night for a couple, of hours as it was chilly here, it cost us in the region of 60p. 

danrv

Gerry1 said:

If your 'old and cold' NSH used to work OK it may just need a failed element to be replaced.  That's cheap and easy.

Yes. An electrician or competent Diy’er would be able to check the Ohms reading on the elements. My old warm air storage heater was found to have one that was lower than the others.