Heating a house via electric

andyrpsmith

The Cadiz Oil free is just a shell with an element and a large empty space all for £150. A cheap £20 convector provides the same effect. The Rapido has a fast warm element (500W) in the air space around the main oil bath, and two additional heaters within the oil bath. The warm up time is about 10 mins without the fast warm and it all costs considerably less than the Cadiz. If you want instant heat then a simple convector is fine but not at £150.

I agree with you on using the higher heat settings it gave a lower overall running cost during my measurements as the heater could choose the best combination of heat settings when using the modulation function.

samtheman1k

Pincher wrote: »

What's wrong with it on 3kW setting, and cycling on and off?

It means your room will get warm/cold/warm/cold/warm/cold...whereas if you can match the room heat loss to the heater output, then it remains a nice constant temp...and more important, it stops the bimetalic strip clicking every few mins, which gets really annoying!

pothole50

samtheman1k wrote: »

It means your room will get warm/cold/warm/cold/warm/cold...whereas if you can match the room heat loss to the heater output, then it remains a nice constant temp...and more important, it stops the bimetalic strip clicking every few mins, which gets really annoying!

Interested to know how you match the room heat loss to the heater output, I thought the idea of the thermostat was to maintain the temp it is set to, or am I missing something here.

Instruction for the electric fire states turn the thermostat to max once an ideal temp is obtained slowly turn the thermo down until a click is heard, the heater then will maintain the room at a constant temperature.

penrhyn

Not forgetting that the outside temperature will have a significant effect on the amount of heating required.

HappyMJ

pothole50 wrote: »

Interested to know how you match the room heat loss to the heater output, I thought the idea of the thermostat was to maintain the temp it is set to, or am I missing something here.

Instruction for the electric fire states turn the thermostat to max once an ideal temp is obtained slowly turn the thermo down until a click is heard, the heater then will maintain the room at a constant temperature.

That constant temperature though with a 3kw heater will be 21 before it turns off then triggers on at about 18 to bring it back to 21 then it goes off then cools down to 18 before it comes back on again. With a 1kw heater setting it will take a lot longer to go from 18 to 21 before it switches off and that's if it ever gets there. The heat loss of the room might be around 1kw at 20 degrees so you would get the constant temperature by turning it down to the 1kw setting but at a slightly higher overall usage/cost as you have posted.

BTW...the supply fuse to your property should be rated at 100A which should allow you to run around 8 3KW radiators all on max. so you won't be blowing the main supply fuse if they are all on...and they take ages to blow even when overloaded anyway.

dunloadin

HappyMJ wrote: »

BTW...the supply fuse to your property should be rated at 100A which should allow you to run around 8 3KW radiators all on max. so you won't be blowing the main supply fuse if they are all on...and they take ages to blow even when overloaded anyway.

Poor advice, sticking 8x 3KW radiators in the ring mains will overload the 16A max they are allowed!!! Remember storage heaters have there own dedicated circuits and fuses/CB's.

You'd be surprised at how few houses have 100A fuses fitted into the cutouts, most are 80A, some just 60A.

HappyMJ

dunloadin wrote: »

Poor advice, sticking 8x 3KW radiators in the ring mains will overload the 16A max they are allowed!!! Remember storage heaters have there own dedicated circuits and fuses/CB's.

You'd be surprised at how few houses have 100A fuses fitted into the cutouts, most are 80A, some just 60A.

Well pothole50 already is drawing almost 23A by having a load of 5.23kw between 14.00 and 15.00 so it's not 16A then isn't it.... There are usually two ring mains in a house and they are usually protected by a 30A breaker each.

Even if a house does have a 60A main fuse then it can still draw almost 14kw at full power. The main fuse is a slow blow fuse so needs to be overloaded by at least 100% i.e 28kw to blow relatively quickly. It will still take 20 minutes. If you would like to say poor advice then OK but 16A at 230V is only 3.7kw. I think a lot of houses can easily draw more than that.

bungle4by4

mmm i wonder what this thread would be like in 5 to 10 years... with gas prices going the way they are, and more nuclear (non gas) power coming on line . .

pothole50

HappyMJ wrote: »

Even if a house does have a 60A main fuse then it can still draw almost 14kw at full power. The main fuse is a slow blow fuse so needs to be overloaded by at least 100% i.e 28kw to blow relatively quickly. It will still take 20 minutes. If you would like to say poor advice then OK but 16A at 230V is only 3.7kw. I think a lot of houses can easily draw more than that.

I have blown this fuse!!! I have been in the house 30 years and its the first time it has blown. It is the old ceramic type the guy who got the power back on said its 60amp fuse wire which I saw him replace. If I start all my fires at the same time pulling 11kw have a shower 8.5kw and boil the kettle 3kw thats 22.5kw too much for the fuse wire. Not sure what a slow blow fuse is but I am sure it cant be something as simple as a 60A fuse wire. The guy did say he would put a request in to update the fuse but that was 5 weeks ago.

dunloadin

There not really slow blow fuses, they are rated at 60-100A but at 415Volt, so can take a much higher load than expected, they are there to protect the DNO's gear more than the house...thats what the consumer unit with it's fuses/CB's/RCB's/RCBO's etc is there for.

If you have a ceramic fuse on the main supply coming in then your way overdue getting a new one, chances are that theres a rolling project to replace them, DNO's will change them sooner if theres a problem.

HappyMJ, your right of course about most houses having two rings at 30A (bit of a brain-fart on my part), that said, assuming all houses have a 100A fuse and can take 8x 3KW heaters is a bit naughty. Stick the heaters on, then a few tellys, lights, the cooker and maybe a shower and we're all of a sudden in 'wheres that burning smell coming from' territory. Even more so if it's an older property or a flat with 16mm tails (or less).

I've got a nice smelly burnt meter in the van at the moment, DNO fuse (60A) did not blow but the 16mm tails overheated, luckily the owner noticed it before any fires started. Turns out the new power shower they had fitted took the load OTT (pulled approx 40A when I checked it). No doubt the sparky (or DIY'er) who fitted it assumed that a 100A fuse was installed and was OK for the job eh.