NC 1700 Auto Series a Storage heater

[Daveydub]

My daughter has moved into a flat with 4 storage heaters and economy 7. They are all NC xxxx auto and one also has a convection heater built in to it. I understand that the input control is simply a thermostat that controls the temperature of the core and therefore the amount of stored heat. The output control is marked 1 to 6 with 1 being No Boost, 3 being evening boost and 6 afternoon boost. I do not know what this control is actually doing and whether any kind of timer is involved. Can anyone explain it to me please or possibly point me to a user manual or exploded diagram? Thanks Dave

 

[flameport]

Output just controls a mechanical flap inside, which when open allows more air to flow through the core so more heat escapes.
The adjustment is attached to a bimetallic strip inside which will open the flap at various temperatures to allegedly allow more heat out at certain times. There is no timer.

For most situations output should be set at minimum and left there.
The input control should be set so that by about 11pm there is little or no heat left in the core. The 'auto' part should reduce the heating time based on the room temperature so that on warmer days it stores less heat anyway.

For at least one night, set all of the inputs to maximum and in the morning check that the heaters are evenly hot all the way across. If not, then one or more elements will require replacement.
Finally - do not place towels, clothing or anything else on the heater, including in the day when they are not powered, as this will cause the cutout to operate and they will no longer work.

 

[Daveydub]

Thanks for that info. I will get her to do the turn them all up full to test all elements. Still not quite clear, presumably the bimetal strip is in the air inlet so opens closes vents according to room temperature. 1, being no boost means flaps are fully open and heat is soon lost. 3 partly open therefore some heat remaining for the afternoon. 6 fully closed therefore some heat remaining for the evening. The problem with that is that 3 is shown as evening boost and 6 is afternoon boost which is the reverse of the logic above. Sorry if I am being dim here. Cheers

 

[flameport]

1 = fully closed and will never open. This is what you want. Mechanically inside it is the strip not being used at all and the flap held closed by gravity.

On the other settings the strip will operate the flap, it will be closed when the heater is hot, but will open at some point as the temperature falls, usually when you don't want it to. When open, heat is lost very quickly.
6 is intended for use in offices and similar, and will result in all of the heat being output during working hours so there is little or nothing left by about 6pm.

 

[Daveydub]

Thanks very much. Now I get it. 1 is fully closed no boost means no heat allowed out ever rather than no heat left for a boost. All makes perfect sense. Cheers

 

[Daveydub]

Are modern storage heaters much of an improvement over these ones. I can imagine that modern insulation materials and fan to assist heat output could have improved control significantly. Any recomendations for heaters to look at?

 

[JohnD]

the price of new storage heaters is likely to outweigh the benefits.

There are a surprising amount of newish storage heaters to be seen in skips. Sadly they are not very suitable for people who are out at work all day. If you are retired, or have a small baby, and are mostly at home and want warm daytimes, they may suit you.

 

[ericmark]

Early systems had a dedicated room in centre of the house and fans, latter systems used well insulated water tanks, but for a radiator type unit they have never been much good.

The problem is although the economy 7 and 10 gives you cheap off peak power, you also pay more for the peak power, so first thing is to decide if worth having off peak power? So first thing is define efficiency, and the normal way is to compare time taken to heat room to time the room is used. So if it takes 1 hour to heat ready to use and is used for 1 hour that is 50% efficient. Using that if a room is used for 6 hours at night and to do that it is heated for nearly 24 hours then the efficiency drops to 25%.

So if we look at other end of the scale the fan heater is very fast so likely no more than 1/2 hour before you occupy the room so efficiency goes right up. Not talking about inferred and heat pumps as then it gets really complex.

But one would think with 4 storage heaters we are looking at 4 rooms and it is unlikely you need to heat all rooms at the same time, so it is possible doing away with storage heaters could actually reduce bills and increase control, however there are other factors, I lived in a semi-detached house where the neighbour had the central heating up really high, we hardly used any gas, then the neighbour moved out and our gas bill got silly, there was it seems good insulation to outside but very poor between houses. So with flats what your neighbour does can really effect your bill and what you need to do, if neighbour has off peak power likely over night you will need no heat, and if you then go out to work, you would only need to heat 1/2 hour before you get home to approx 10 pm then the house would start to cool over night.

So in real terms only way to know is to try it. Start by same time every week reading meters and recording, borrow or buy some fan heaters, turn off the storage heaters for a week and use fan heaters instead as required, and then work out which is cheapest. Also consider is it too warm at night at the moment or too cold in the evening, once tested then you will know if off peak fits your daughters life style. There are other considerations like if there is enough power into the flat, but the basic point is, before looking at different storage radiators, work out if storage radiators suit her life style, likely young children pre-school then yes off peak good, but even when daughter at home in the day, with everyone else out I would guess she be busy and would not want house too warm anyway. And with fan heaters you only heat rooms being used. OK fan heaters not very pretty, but basic lighter the heater the quicker to heat.

 

[Daveydub]

Thanks all. She only moved in a few months ago and so we are waiting to see how the winter goes. It is one of those blocks of flats that is almost entirely occupied by old ladies, quite funny that my daughter is in a "retirement home " before me. As you say, heating a flat is always very dependent on the adjacent flats so she will try this winter and see how she gets on. I just thought that with more modern materials they could make storage heaters much more controllable but it sounds as if they have not really improved them much. I always used to think of them as ideal for old folks, warm house all day and by teatime they are sat in front of the fire anyway. Now that I am an old folk myself this is not really my pattern so maybe it was always a misconception.

 

[flameport]

Are modern storage heaters much of an improvement over these ones.

No, they are essentially the same.
Some very old ones (far older than those you have) were much larger, as the bricks could store less heat.
However bricks in those you have and new ones are no different, and the amount of insulation is similar.

There are heaters such as Dimplex Quantum which may be marginally better, as they have a fan and dual heating elements, but installed they will cost ~£1000 per heater - money you will never recover.

Unless the heaters you have are literally falling apart there is nothing to be gained by replacement. Replacement parts such as elements are still available and relatively inexpensive.

 

[Daveydub]

Thanks for all of your advice
Cheers
Dave