Electric boiler - just using boost?

cupofjava

Hi guys,

I've just moved into a one bedroom, all electric flat. The heaters aren't linked to the hot water boiler, and so are just standard (i think oil filled?) radiators in each room that you can switch on and off individually as you like.

This makes the hot water tank rather redundant aside from my quick shower before work in the morning. Now, for the past week or so i've just been using the 'Timed Boost' option, to provide half an hour of boost in the morning - this gives me plenty of hot water for my morning routine. I don't have E7, so heating it through the night isn't a good option for me.

I'm confused as to if this is the best way to go about cutting costs though? how does boost work? is it just an element at the top of the tank, or does it actually suck more energy to heat it quicker? would i be better setting the conventional timer, and not the boost timer, for an hour or so in the morning? It would probably be slower, but would it use less power?

sorry if this has been asked before - i've tried to the search function but not had any specific answers to this.

thanks!

rogerblack

Does the water go cold if you run it a bit longer than normal?
If so - then you're doing the right thing - and not heating up more water than you need.
If it stays hot for half an hour - then you want to investigate further.

cupofjava

Hi,

Yes. Essentially if the boost is on for half an hour before I get up, it provides enough water for probably 10 minutes or so in the shower. If I have a longer shower it runs cold. My question was more about how boost works... Whether it actually uses any more power to 'boost' the heater and heat it quicker than if I just used the normal time clock without boost.

macman

It would use the same amount of power to heat it from the same 'cold temp' to the same 'hot temp' whether you use a normal setting or a boost setting (assuming that 'boos't offers a higher rating). It would just do it more quickly.
Regardless of speed, the same input of energy is required to do the same amount of work.
Sounds to me like a dual-element immersion heater. The boost element is shorter and just heats the top part of the cylinder (it's not a boiler) more quickly. Probably left over from an era when the property had E7 and NSH's installed.

rogerblack

cupofjava wrote: »

Hi,

Yes. Essentially if the boost is on for half an hour before I get up, it provides enough water for probably 10 minutes or so in the shower. If I have a longer shower it runs cold. My question was more about how boost works... Whether it actually uses any more power to 'boost' the heater and heat it quicker than if I just used the normal time clock without boost.

I don't know how the elements work - this is largely irrelevant in this case - if you have heated the right volume of water - and the rest of the cylinder has remained cold - you have used the least energy you can.
My understanding is that 'boost' would normally be for houses with economy 7.
Boost would be used when you've run out of stored hot water that has been heated overnight.

Richie-from-the-Boro

cupofjava wrote: »

Hi guys,

I've just moved into a one bedroom, all electric flat. The heaters aren't linked to the hot water boiler, and so are just standard (i think oil filled?) radiators in each room that you can switch on and off individually as you like.

This makes the hot water tank rather redundant aside from my quick shower before work in the morning. Now, for the past week or so i've just been using the 'Timed Boost' option, to provide half an hour of boost in the morning - this gives me plenty of hot water for my morning routine. I don't have E7, so heating it through the night isn't a good option for me.

I'm confused as to if this is the best way to go about cutting costs though? how does boost work? is it just an element at the top of the tank, or does it actually suck more energy to heat it quicker? would i be better setting the conventional timer, and not the boost timer, for an hour or so in the morning? It would probably be slower, but would it use less power?

sorry if this has been asked before - i've tried to the search function but not had any specific answers to this.

thanks!

Depends where the element is [top bottom middle] what size the tank is and what output the element is.

Boost .. .. on an E7 system is a timed 60 minutes, heating only 10% [ish] of water at the very top of the vessel.

- a 27" element in the bottom and you will get a cylinder full of boiling water
- a 27" boost element in the top and you will get less than a 1/4 cylinder full of hot water if you are very lucky

Boost .. .. on your non-E7 system is a timed 30 minutes, heating only 10% [ish] of water at the very top of the vessel if you have only one elements at the top of the cylinder. It would be 30% [ish] middle and 90% [ish] if the element was at the bottom.



Liquid, such as water, is heated from the bottom, the layer of water closer to the heat source expands and hence becomes less dense compared to the water layer above it. Expanded water is less dense than the surrounding water and therefore it rises. The cooler regions of the water in the upper part of the flask, being denser, sink. This movement of liquid due to a difference in density sets up a convection current.

So the heated [hot] water pushes up and forces the cooler water down over the thermostat which in turn is heated until the whole volume of the tank reaches your pre determined setting then the stat switches the leccy off. Its a bit atomic science and the random motion of atoms and all that, but sufficient to say that's why the top down element is rubbish at heating a full tank of water

NOTE : Like Roger says, it sounds as if you have an old Horstmann Economy 7 Quartz water controller on a non E7 system. Hope this helps my friend.

cupofjava

Thanks for the guidance guys. I think you're right - although the flats are relatively new (2007) I don't think they ever had storage heaters. It is a horstmann e7 timer clock on a mega flo efficiency boiler. The timer was actually only fitted very recently. The old mechanical one broke and they fitted this digital one about a week ago.

So my understanding really is that for half an hour or so, boost would be more effective... If I need to heat a lot of water I'm better off using the standard heating function, as that will heat more effectively from the bottom? Regardless, the main thing is to just heat the ideal amount needed.

Thanks!

Yolina

cupofjava wrote: »

Regardless, the main thing is to just heat the ideal amount needed.

Yep

Just bear in mind that as we head into winter, you may need to have it on for a bit longer as the temperature of the water coming in will be getting lower and therefore will take longer to heat up.

On my set up (a "vintage" gas boiler + 210L tank) I leave the HW for 10 minutes longer in winter.