Understanding storage heaters.

QrizB

The storage heaters are all Quantums?

If so, I'd suggest that you leave them all on and let them decide amongst themselves how much to charge each night.

Gerry1

• Your immersion heater probably has two elements. The lower one should be on an Economy 7 circuit that's only live overnight.  Unless you’re away, it should be left on permanently.
  
  The upper one should be on a circuit that's always live.  It should normally be left off, being switched on briefly to get half a tank of very expensive hot water only if you've been away for a while and come back to a cold tank, or if you occasionally run out of hot water during the day.  Leaving it on by mistake can be cripplingly expensive because the E7 day rate is even more expensive than the single rate.

• Users such as @EssexHebridean, @RedFraggle and @Bluebird67 will doubtless know best, but I'd set the living room ones to the same hours and same temperatures that you're comfortable with.  Probably a bit of trial and error, balancing comfortable temperatures with the bills.  Ditto with the hallway one, perhaps with slightly lower temperatures and operating hours.
  
  
• You probably have panel heaters in the bedrooms.  That makes sense if the rooms are not occupied during the day, e.g. working from home.  If you leave the doors open during the day you should only need to use them briefly before going to bed and getting up.
  
  
• Make sure you know the exact E7 start and finish times.  Forget what times they're supposed to be, what your meter is doing is all that matters.  Check the times when the red light on the upper immersion heater is on.

SpikeyKitten

QrizB said:

The storage heaters are all Quantums?

If so, I'd suggest that you leave them all on and let them decide amongst themselves how much to charge each night.

They are, but apparently quite old ones. No smart tech etc.

SpikeyKitten

Gerry1 said:

• Your immersion heater probably has two elements. The lower one should be on an Economy 7 circuit that's only live overnight.  Unless you’re away, it should be left on permanently.
  
  The upper one should be on a circuit that's always live.  It should normally be left off, being switched on briefly to get half a tank of very expensive hot water only if you've been away for a while and come back to a cold tank, or if you occasionally run out of hot water during the day.  Leaving it on by mistake can be cripplingly expensive because the E7 day rate is even more expensive than the single rate.

• Users such as @EssexHebridean, @RedFraggle and @Bluebird67 will doubtless know best, but I'd set the living room ones to the same hours and same temperatures that you're comfortable with.  Probably a bit of trial and error, balancing comfortable temperatures with the bills.  Ditto with the hallway one, perhaps with slightly lower temperatures and operating hours.
  
  
• You probably have panel heaters in the bedrooms.  That makes sense if the rooms are not occupied during the day, e.g. working from home.  If you leave the doors open during the day you should only need to use them briefly before going to bed and getting up.
  
  
• Make sure you know the exact E7 start and finish times.  Forget what times they're supposed to be, what your meter is doing is all that matters.  Check the times when the red light on the upper immersion heater is on.

Storage heater in the bedroom too, but there's no discussion whether that one should be on or off. Luckily they have timers so it lets heat out in the morning, then again in the evening.

Spoke too soon about the water being sorted. Got back this evening to no hot water again. I give up, I've tried my hardest to understand this cryptic system. I'm calling the landlord. I don't know why they didn't leave instructions. It's not at all obvious how it's all supposed to work.

Thanks everyone.

Gerry1

Just set the bedroom heaters to the times and temperatures you want.  Probably relatively high about half an hour before you rise (assuming the fan isn't too intrusive), much lower during the day (just enough to prevent mould and damp when you're away or if the door is shut), and higher again just before going to bed.

The principle is to tell them when, where and how warm you want to be, then just letting them do their own things.  Tweak as necessary according to experience (the bills, the bills !)

Gerry1

SpikeyKitten said:

Gerry1 said:

• Your immersion heater probably has two elements. The lower one should be on an Economy 7 circuit that's only live overnight.  Unless you’re away, it should be left on permanently.
  
  The upper one should be on a circuit that's always live.  It should normally be left off, being switched on briefly to get half a tank of very expensive hot water only if you've been away for a while and come back to a cold tank, or if you occasionally run out of hot water during the day.  Leaving it on by mistake can be cripplingly expensive because the E7 day rate is even more expensive than the single rate.

• Users such as @EssexHebridean, @RedFraggle and @Bluebird67 will doubtless know best, but I'd set the living room ones to the same hours and same temperatures that you're comfortable with.  Probably a bit of trial and error, balancing comfortable temperatures with the bills.  Ditto with the hallway one, perhaps with slightly lower temperatures and operating hours.
  
  
• You probably have panel heaters in the bedrooms.  That makes sense if the rooms are not occupied during the day, e.g. working from home.  If you leave the doors open during the day you should only need to use them briefly before going to bed and getting up.
  
  
• Make sure you know the exact E7 start and finish times.  Forget what times they're supposed to be, what your meter is doing is all that matters.  Check the times when the red light on the upper immersion heater is on.

Spoke too soon about the water being sorted. Got back this evening to no hot water again. I give up, I've tried my hardest to understand this cryptic system. I'm calling the landlord. I don't know why they didn't leave instructions. It's not at all obvious how it's all supposed to work.

As previously described, lower heater on, upper heater off.  It's quite possible that one immersion heater element has failed or its fuse has blown.  Do the relevant parts of the Storage Heater Sanity Test (i.e. only for the immersion heaters).  If the water is cold in the day, switch everything else off, switch on the upper immersion heater, count the flashes and calculate the extra power being drawn.  It should be around 3kW.  If it doesn't change, isolate the spur and replace or swap the fuse.  If no luck, the element is faulty so tell the landlord.

Similar procedure late at night when you are sure E7 has kicked in.  Make sure the upper immersion heater is switched off, as it should be.  As above, count the flashes and calculate the extra power being drawn.  It should be around 3kW.  If it doesn't change, isolate the spur and replace or swap the fuse.  If no luck, the element is faulty so tell the landlord.

RedFraggle

For the Quantums I'd leave them all on in the rooms you want to use them in. They'll work it out between them. We don't use the old NSH in the bedroom as it leaks too much heat overnight but use an oil filled rad instead.
Is the hot water a thermal store like a gledhill or an immersion?

Scot_39

SpikeyKitten said:

QrizB said:

The storage heaters are all Quantums?

If so, I'd suggest that you leave them all on and let them decide amongst themselves how much to charge each night.

They are, but apparently quite old ones. No smart tech etc.

The non RF models - the smart link bit - were available direct until or from local fitters in my case - I was uoted them and the RF with the smart hub - about 3-4 years ago.  I went for neither - a mistake as would have saved more at crisis rates than I  used for payback calcs.

IIRC Heatstore models were very similar to non RF Quantums - even the manual was in places page for page.

Even some of the older ones had some intelligence built in - like open window detection - and if you had 2 or more in one room - they had a slave mode (which was renamed to second heater mode or some such in later series manuals iirc)

The RF Quantums got as far as something like series G.9 when last downloaded a manual - on software type and diagnostic facilities - but many shared nuch of the same user programmability as earlier versions iirc - so you need to try and find out your exact generation - and then get your versions  / series manual from the Dimplex site.

For modern versions its under the programming flap

https://tradehelp.gdhv.co.uk/support/solutions/articles/79000140198-how-do-i-identify-what-series-my-quantum-heater-is-

SpikeyKitten

Ok, I have discovered they are 'G' series. Two QM150. One QM125. One QM070.

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.

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?

QrizB

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.