Understanding storage heaters.

SpikeyKitten

QrizB said:

SpikeyKitten said:

One thing I fail to grasp about storage heaters is when people say: "how much they'll cost depends on how cold it is outside". Like, how? How does the storage heater know what the weather is like? It still spends all night charging up regardless.

Think of the storage heater as a bucket of heat.

It starts the day full(ish), having charged to a set temperature overnight.

Then during the day it lets out as much heat as it needs to, in order to achieve the room temperature you want. For older heaters, you manually adjust the louvres; for new ones like your Quantums, they adjust themselves automatically.

At the end of the day, there could be three possibilities:

1. The bucket isn't empty and the heater still has stored heat. This heat won't be replaced when charging the following night. Depending on how much there is left, the heater might reduce the charge level setting (the bucket fills less than it did the previous night).
2. The bucket just lasts the day, and the heater is cold. I don't know the Quantum algorithm but the heater might decide to charge a bit more the following night (so you don't run out, if the heat demand is the same tomorrow).
3. The bucket runs dry (heater goes cold) before the end of the day, and it has to top up using day-rate electricity. In this case the heater will definitely increase the charge level (fill the bucket more) the next night.

So no, the heater doesn't know how much heat you'll need; but it knows how much you needed the previous day, and will adjust accordingly. It won't "spend all night charging up", it'll onl charge with as much heat as it thinks you'll need.

SpikeyKitten said:

So now I have the model numbers I can input the figures into an online calculator, which gives me a rough figure of around £80 per week to run all four. Does sound about right?

The 070 holds 10.9kWh, the 125s each hold 19.3kWh, and the 150 holds 23.1kWh. That's a total of 72.6kWh if they all charge from cold to max. I don't know your tariff, but if your off-peak rate is ~15p/kWh that would cost about £11 a day. So £80 a week would be right if every heater needs to charge completely every night of the week.
But unless we're having a very cold spell, they'll probably use much less than that.

Thank you. That explains it perfectly. I've had the one in the bedroom (QM150) going for about a week now and it's lovely and warm. I notice in the manual that you can see how long they charged up for the previous evening. Just checked and it was 420 minutes, or seven hours. Which is basically all night. But maybe it is cold outside, and none of the other heaters have been switched on yet so possibly trying to warm the entire flat to 20 degrees rather than just the bedroom. I'm starting to get it, thank you for your patience.

Scot_39

You sure your not looking at the available charge window rather than the actual energy taken 

See for instance the screen  shots and video link here this set for g.6 series.

You might want to find your exact version by searching the site.

It's aimed at a mix of folk including contractors.

https://lms.gdhvacademy.com/mod/book/view.php?id=1315&chapterid=500

Lot 20s and HHR with fans can certainly output more energy than old passive ones like mine.  But the 150 would be taking 23kWh over 7 hrs  - which is more than I've been using for the last couple of days for a 2 bed mid terrace - but I heat a lot more sparingly than 20C

SpikeyKitten

Maybe it is the available charge window. There's nothing in the operating manual about it. I can't remember where I read that it was the minutes charged number, somewhere online. I hope it's available charge. All of mine are showing 420, so either they're all charging up from empty every night or it's the available charge like you said. 

I'm just figuring it out regarding temperature. Turned them all down now to the lowest setting without entering holiday mode, which is 14C. See how that goes for a bit. I'm usually at work, or in bed. At weekends usually out. Ideally I'd like just the bedroom a nice temperature, and everywhere else just a minimum/take the edge off. By the time I figure it out it'll be summer 

Scot_39

just realised I forgot to add the old manual link pages on the GDHV site

https://tradehelp.gdhv.co.uk/support/solutions/articles/79000134079-where-can-i-find-an-instruction-manual-for-my-quantum-heater-

If your out that much the out all day mode might be a good start point on older series or user / out all day on new - for most of your heaters - even probably the bedroom.