I just moved into a Flat also with storage heaters. It seems though that I have a range of storage heaters for the flat, so I thought I'd pass on my experence of them.
In the living area I have a Combe Storage Heater. One side says Storage, then other Convector.
Storage is how much heat one will need for the next day. I normally set this to 3, as I feel comfortable with it and gives me the heat I need.
The Convector button is a second heater which acts as a Top Up for for when the storage is running out or you need to get a little more heat. This I mainly keep off, as stored heat is enough for my needs.
Secondly depending on your electricity settings the convector would come on Mid Afternoon as a top up, but you'll be charge more, as you'll be using standered charge and not Economical 7.
Others would be that the convector can come on as needed.
In any case never use both, as it will be like running two heaters for one room.
Another of my storage heaters has and Output button. This is a standerd storage heater that would store the heat and slowly let it out.
Output should be set to Min, so that the heater can store heat. You will still get heat from the heater from this setting, but only open when your in the home. I normally open to 1 or 2, but when leaving the flat for 2 to 3 hrs turn output to min. Enough heat will leak out, but most will be kept in for the evening. There is also a metal bar in these types of heaters which opens and closes to the output setting you need which is why output should be set to min, to lock the heat in.
All thats left to say is if your heaters have Convector buttons, keep these off untill needed, thus you should have cheaper billings, as you'll not be using two heaters at a time.
Craig Humphries, March 2010