Possible Airing cupboard heater

[mprice109]

Hi ALL

I'm thinking of adding a towel rail / radiator into an airing cupboard which has recently lost its hot water tank, due to an old semi gravity central heating system being updated with a new combi boiler ( now located elsewhere ). I've tried to show in the picture below what my thoughts / plan would be . The 230v supply would be taken from the old immersion heater socket . I'm not an electrician so I'm looking for some advice please :-

Firstly can anybody see anything wrong or dangerous with this setup ? will it work ?

Secondly Am I correct in thinking that the heating element ( 800 watts - 3.5 amps ) in the electric towel rail / radiator is classed as a " RESISTIVE LOAD " and would be within the 5amp limit of the digital room stat ? or will the wattage need to be adjusted down to bring it under the 3 amp inductive limit .

Thirdly is it ok to use stranded 1mm2 flex cable ? or should this be solid core 1.5mm2 twin and earth cable ? ( not sure if I've read somewhere room stat terminals are designed for single core wires ? if this is the case could I just crimp a ferrule on the stranded flex cable ? )

Any advice or thoughts would be much appreciated
Thanks in advance
mark

 

[JohnW2]

I'm thinking of adding a towel rail / radiator into an airing cupboard which has recently lost its hot water tank, due to an old semi gravity central heating system being updated with a new combi boiler ( now located elsewhere ). I've tried to show in the picture below what my thoughts / plan would be . The 230v supply would be taken from the old immersion heater socket . I'm not an electrician so I'm looking for some advice please :-

Fair enough. I've done every similar.

Firstly can anybody see anything wrong or dangerous with this setup ? will it work ?

Not anything that looks wrong or dangerous to me.

However, do you actually need the thermostat - does the heater not have a uilt-in one?Of you do need the thermonstat, you need to be sure that everyone is on the same page as regards what 'NO'and 'NC' means - you want to use the contact which closes when temperature goes below the set value.

Secondly Am I correct in thinking that the heating element ( 800 watts - 3.5 amps ) in the electric towel rail / radiator is classed as a " RESISTIVE LOAD " and would be within the 5amp limit of the digital room stat ? or will the wattage need to be adjusted down to bring it under the 3 amp inductive limit .

No problem - although, of course, if you don't need the thermostat, that potential issue would go away.

Thirdly is it ok to use stranded 1mm2 flex cable ? or should this be solid core 1.5mm2 twin and earth cable ? ( not sure if I've read somewhere room stat terminals are designed for single core wires ? if this is the case could I just crimp a ferrule on the stranded flex cable ? )

The flex would be fine.

Kind Regards, John

 

[Taylortwocities]

I agree that the thermostat is not really needed. The heater doesn't need to be airing clothes 24 hours a day and I would not want an 800watt load to be running 24hours a day!
This guide calculates that an 800watt load would cost you £9.74 a week!

Electric Heating Electricity Cost Calculator

Running costs & power consumption for fan heaters, convector heaters, oil-filled radiators and halogen heaters.

www.sust-it.net

Suggest a timer would be better. Even better if you set the timer for a cheap rate period (if you have somerhing like economy 7, or Octopus Agile, etc)

 

[mprice109]

Good morning both

However, do you actually need the thermostat - does the heater not have a built-in one? Of you do need the thermostat, you need to be sure that everyone is on the same page as regards what 'NO' and 'NC' means - you want to use the contact which closes when temperature goes below the set value.

The room thermostat is programmable .
My thought process was if I go with a manual heating element and not the more expensive version with one built in I could place the room stat at a reasonable height and position within the cupboard , set it at a fixed temperature and close the door , this would then only call for heat when the temp drops out of range using very little energy in the process . The cupboard is roughly 750mm square in centre of the house with the door only opened to retrieve towels etc.. so I'm expecting practically no heat loss

Thanks for your comments
mark

 

[Taylortwocities]

The room thermostat is programmable .

OK, then the programmable stat will let you set a programme for less hours once you have received your first lekky bill!

 

[Murdochcat]

Fwiw I think the op is over thinking this

One of these would be a reasonable solution and won’t take up much space either

Dimplex 120w 960mm/3ft Thermostatic Tubular Heater | Dimplex (ECOT3FT / X-049681)

 

[mprice109]

OK, then the programmable stat will let you set a programme for less hours once you have received your first lekky bill!

Do you think 800 watts is to much ??
Is there any / much difference between lower wattage on for longer or higher wattage on for shorter periods ain't they very similar over the longer term

 

[mprice109]

Fwiw I think the op is over thinking this

One of these would be a reasonable solution and won’t take up much space either

Dimplex 120w 960mm/3ft Thermostatic Tubular Heater | Dimplex (ECOT3FT / X-049681)

did think of one of these, thought they would be on the small side . ( That's only when comparing 1600 x 400 towel rails with each other mind )
is there a guide / rule of thumb that's common knowledge to others I could reference ?? didn't want to buy stuff and it be rubbish and not up to the job .
Pay once , do once and forget about . that's the plan

thanks for your comment
mark

 

[Murdochcat]

Do you think 800 watts is to much ??
Is there any / much difference between lower wattage on for longer or higher wattage on for shorter periods ain't they very similar over the longer term

800 is far too much for a small cupboard

stick a thermostat in the cupboard and see how hot it is and then how little energy you'll need to raise the temperature .........

 

[JohnW2]

Do you think 800 watts is to much ??

I personally do.

In a similar situation I have used one of the tubular heaters which has been mentioned (100W or do), using its own thermostat) and that keeps the cupboard plenty warm enough.

Is there any / much difference between lower wattage on for longer or higher wattage on for shorter periods ain't they very similar over the longer term

Not a lot of difference. In fact, if one had a 'perfect' thermostat(i.e.with no hysteresis), there would probably be no difference at all. However, in terms of the real world, the temp in the cupboard would probably be more constant with a low-power heater which was on for a fair bit of the time than a much higher powered one which only added 'bursts of heat' relatively infrequently.

Kind Regards, John

 

[big-all]

i would actually put a high and low vent on the door as the humidity and heat would be perfect for growing herbs
seriously--gentle heat over several days is far different as it airs the clothes you should never put anything other than dry washing in an airing cupboard --are you trying to dry washing in there ??

 

[mprice109]

i would actually put a high and low vent on the door as the humidity and heat would be perfect for growing herbs
seriously--gentle heat over several days is far different as it airs the clothes you should never put anything other than dry washing in an airing cupboard --are you trying to dry washing in there ??

not trying to dry washing just trying to replicate as it was when the hot water tank was there .
as far as humidity and heat wouldn't that be controlled by the room stat ??

If I set it to say 22 degrees wouldn't that be the temperature give or take a degree ??

 

[mprice109]

I personally do.

In a similar situation I have used one of the tubular heaters which has been mentioned (100W or do), using its own thermostat) and that keeps the cupboard plenty warm enough.

Not a lot of difference. In fact, if one had a 'perfect' thermostat(i.e.with no hysteresis), there would probably be no difference at all. However, in terms of the real world, the temp in the cupboard would probably be more constant with a low-power heater which was on for a fair bit of the time than a much higher powered one which only added 'bursts of heat' relatively infrequently.

Kind Regards, John

I was thinking of this plus a bit . ( there is very little difference in price of the extra wattage in the heater )
maybe I'll drop the fuse rating down to 3amp and use a 600w heater

 

[big-all]

i would definitely go no greater than 120w even that will get very warm unless the heat can escape into the attic then even iff badly working its sub £1 a day or about £300 a year and possibly half that working propperly

 

[EFLImpudence]

I am sure it should not be escaping into the attic.