Dimplex Convector Heaters

[PMC1959]

I am looking at getting 5 of these heaters (2000w) installed in my flat. Reading through some previous threads it sounds as though each one of these heaters should be on their own 20a radial circuit (rather like my old economy 7 system) and I would assume this is what my electrician would do.
However looking at some of the optional extras you can get with these heaters you can get a mains powered control unit and some receiver cassettes for each heater which allows you to control the temperature and times of each heater. I looked at the specification sheet for the control panel and it said that all the heaters and the panel must be on the same circuit. This seems to go against the advice of putting each heater on an individual circuit.
Any thoughts on this?

Pete.

 

[ColJack]

copy of the spec sheet?.
model number?
without seeing the instructions ourselves we can't say.

it may be that the system uses "coms over mains" which has some fancy name that I can't remember..
basically it send the control signals back down the mains wire, so they all need to be on the same phase and same CU.. ( so that they are all at least connected together at some point )

and 10KW of electric heating? why did you have the storage heaters taken out?

 

[ColJack]

yeah, I've looked it up, "mains bourne signaling" is what they call it..
it just means they all have to be from the same CU and on the same phase..
use seperate breakers for each, it's all connected back at the CU anyway..

 

[Steve]

I am looking at getting 5 of these heaters (2000w) installed in my flat. Reading through some previous threads it sounds as though each one of these heaters should be on their own 20a radial circuit (rather like my old economy 7 system) and I would assume this is what my electrician would do.

Thats 10kw of heating.

Now, I'll do some sums for you.

November to Feb, lets call it 3 months, a quarter, one lecky bill.

During this period, your heaters (if correctly sized) spend approximately a third of the time on (off at night). Thats (10x24)/3. Thats 80kwh per day.

At 20p per kwh (worst case), thats £16 per day.

Eco7 would run the heaters on something like 3-5p/kwh for about the same length of time. Thats £2.40.

Clearly there are other variables, including inefficiencies in storing heat. But if you're investing in electric heat, then use your eco7 supply (if its gone, get it back!) The heaters are expensive, but they will cost you much less in the long run.

 

[ColJack]

or an electric "boiler" for that matter..

even air conditioning would be a better option.. they can be run "backwards" to produce heating in the winter and are normally about 300% efficient.. ( you get 3KW of heat out for every 1KW of electricity you put in ) ..

 

[PMC1959]

ColJack, Someone told me about the electric equivalent of a combi boiler (there is no gas supply to the flat), is this what you are mean by electric boiler.
If so could you give me some idea as to what sort of thing I should be looking at. I assume I would then be able to use normal water filled radiators?

 

[Steve]

electric boilers are still terribly expensive to run.

If you have the cash, then a heat pump system will cost you considerably less to run (as above, with 300% yield on energy spent). This extracts heat from the ground and converts it into useful heat for distribution to your radiators, UFH and hot water. It can be combined with solar energy.

Going back to electric boilers, the most you will get for a domestic house is about 11kw. This is not very much, when you consider the output of a gas boiler is in the region of 24-30kw (or more). My shower heater is 10kw, and this only just produces enough hot water for a shower in winter.

More powerful electric boilers are available, but they require a 3 phase supply (ie. 3 x 11kw). You probably cant get this, being in a flat.

 

[ColJack]

The difference with a shower and a radiator is immense..
For a start you're trying to instantly heat close to freezing water to a comfortable temperature all the time.
Secondly it's then sprayed out, creating a large surface area to lose heat before it comes into contact with your skin.
Thirdly it also falls quite a distance giving it time to lose that heat.

A radiator heats a given and fixed amount of water to a given temperature and trys to keep it that way.. you're not returning the water to close to freezing by the time it comes back for a re-heat..
and once the flat is up to temperature, you're only putting heat back into the water that is lost from the flat through walls and such.

heat pumps may not be an option..
he's in a flat, and for all we know it might be a 7th floor flat.. also it's debateable that he's got a garden or permission to dig it up if he has..

http://www.bhl.co.uk/category/Electric_Boilers

 

[kai]

The safest way is to run a B10 breaker circuit for each heater off one consumer unit - Ten Amps is more than sufficient for a 2kW heater - (no need to over fuse the circuit and use expensive 10mm cable) , when 1.5.mm cable and a B10 will do for each one!

 

[PMC1959]

Once again thanks for all your input and advice.

I am now a little confused as to the best solution and could perhaps do with some help.

Its a purpose built ground floor flat (no garden, no gas). One bath, 2 sinks, and no shower (but one is required).

When we moved in there were 2 huge horrible old storage heaters. There looked like there were 3 other storage heater points (fused spurs with no outlet) but the heaters weren't there. There was a second fusebox with 5 fuses and 5 cables coming out. All the cabling was in trunking along the ceilings (looked awful). My wife wanted the heaters, cabling and trunking removed which I did and also had the economy 7 meter removed (maybe I shouldn't have in hindsight). At the moment these is no source of heating in the flat.

The hot water is heated by an old immersion which we have had to get someone out to twice already.

So we are looking at starting from scratch regarding heating the water and heating the house. Any advice on the best way of doing this would be appreciated.

One of the these electric boilers to heat the water and 4 electric heaters for the heating perhaps??

I am looking at getting the house rewired in the very near future so whatever I decide I can incorporate into this.

 

[Lectrician]

Some of the dimplex heaters need a third control core between them for a time clock sync. I think it was called a 'pilot' wire. They did then release a version which had mains born signalling.

You can have more than one heater on a circuit. 2kw is not a huge amount. You could have two on a 20amp circuit (2.5mm radial typically).

The mains borne signalling type was recommended to be installed on the same circuit. The pilot wire type can have heaters on multiple circuits (the same phase), but you MUST then have a THREE pole isolator at each heater to isolate the LIVE, NEUTRAL and the PILOT wire, as this a 230v control wire.

I recall the cassette type timers actually have a battery in them. You fit one to one of the heaters, and it controls all of your heaters. It doesn't turn the heaters on and off, it just turns them from 'day' to 'night', so you need to ensure the night heat setting is very low on each heater if you wish to use the time control as a 'full' off. You can also remove the cassette timer from the heater to program it and them return it to the heater, rather than trying to program it while it is in place.

It may be easier to install a room thermostat similar to a central heating system, a programmable one would offer time control. This would control a contactor which would in turn switch the heater circuits on and off. A 4 pole contactor would be able to switch 4 heater circuit. Two of these would control 8 etc.

A programmable thermostat per floor would also be a good idea.

 

[Chri5]

Check out the electric boiler suitation- they are better than they were and since you must have electric heating and electric water heating then a one unit system offers an alternative.

The weighing up factor will be driven by the cost of:-

rads, water pipes installation + boiler

v

electric radial circuits + heaters x 5 + CU + system controls + h/water

and then which is most cost / eco friendly.


A landlord wouldn't pick up the ongoing cost bill, so site conditions and ease of work / lowest cost will play the big factor.

Private ownership to live in then it's got to be cheapest long term running cost, which is maths you have to do !

 

[Steve]

get the eco 7 meter refitted, and storage heaters with an evening boost facility. Or its gonna cost an arm and a leg to run. Install cost roughly equivalent (5 heaters + water heating + eco7 install vs. wet heating boiler and rads)

 

[JamesdeHaas]

I recently purchased 8 from HSD great value for money, and they also do a price match service on any products that you find that are cheaper. http://www.hygienesuppliesdirect.com/products/prod148343

 

[Taylortwocities]

I recently purchased 8 from HSD great value for money, and they also do a price match service on any products that you find that are cheaper. http://www.hygienesuppliesdirect.com/products/prod148343[/QUOTE]

You should claim back £80 TLC are cheaper by about £10 a pop
http://www.tlc-direct.co.uk/Main_Index/Heating_Index/Dimplex_EVX/index.html


The plug in timers do not have batteries as they are powered from the mains feed.
You do need to factor in the timer control wiring if you plan to do that but get a sparky to help you out with this, you'll be switching on 5 x 2KW all at once and that might need some special engineering.

I hope you left the off peak wiring in place, it may come in useful!