Immersion (yes its another immersion question!)

tommy21

Hey folks, I need some expertise. After years of trying to solve hot water problems in our house (thanks to a few dodgy plumbers), we have finally found a reputable one (had neglected to connect up immersion properly meaning we could only get hot water when boiler was blasting on :eek:). So for the first in years we can run the upstairs shower and bath without any heating on via the immersion. Thing is I know there are two schools of thought - some people say it is cheaper to leave immersion on all the time (my parents and uncle and aunt etc. say this), where as I think this is madness, it must surely be more expensive! This is countered by them saying heating it up from cold costs more.

There is no timer on it or bath/sink switch, just an on/off. Is a timer something we should go with? I refuse to believe leaving it on 24 hrs a day is the right move!

indie armada

if your immersion is a dual type , you will need a bath /sink switch for starters. you could install a timer with a boost function which when pressed will turn on the immersion for an hour only which is usually enough to get the water up to temp and cuts out the danger of leaving it on for long periods by accident. there have been chages to the regs regarding the electrics for water heating in recent times so any work done should be done by someone qualified.
in a lot of central heating systems there is a valve usually in the hot press that diverts the water trough the cylinder only bypassing the rads, i use this in my house and it heats the water in no time, without this valve the hot water has to circulate around the whole system before it heats the cylinder and because that takes much longer it costs more too

astrofool

Horstmann do timers, most electrical suppliers do them, they allow you to set your off peak times, and if you want a timed boost.

I've yet to see a 7 day timer that handles the immersion load directly, I think one of the posters on here (Joey the Lips?) usually wires a 7 day timer up, while ensuring the load is not passed through the timer itself.

meercat

http://www.heatingcontrolsonline.co.uk/horstmann-e246-boost-timer-p-628.html
http://www.maplin.co.uk/module.aspx?C=SO&U=strat310&T=Putney&ModuleNo=12726&ma=Putney+-+Electronic+Immersion+Heater+Time+Controller

cheaper to control by using a timer like these
available in ireland
the first one you press and will turn off automatically at preset time,half hour.1 hour,1 hour half,two hours
the second will come on and turn off automatically
some people prefer the first option as they have more control and it will only switch on when you are there and you dont have to remember to switch it off
both timers have to be fitted before the immersion switch to allow control of sink/bath

steamengine

tommy21 wrote: »

Hey folks, I need some expertise. After years of trying to solve hot water problems in our house (thanks to a few dodgy plumbers), we have finally found a reputable one (had neglected to connect up immersion properly meaning we could only get hot water when boiler was blasting on :eek:). So for the first in years we can run the upstairs shower and bath without any heating on via the immersion. Thing is I know there are two schools of thought - some people say it is cheaper to leave immersion on all the time (my parents and uncle and aunt etc. say this), where as I think this is madness, it must surely be more expensive! This is countered by them saying heating it up from cold costs more.

There is no timer on it or bath/sink switch, just an on/off. Is a timer something we should go with? I refuse to believe leaving it on 24 hrs a day is the right move!

There are two schools of thought alright, but look at it this way. Heat loss is directly proportional the temperature difference between the inside and outside of the cylinder. So the higher the water temperature the greater the heat loss. You are correct IMO.

Make sure the cylinder is insulated and its a good idea to shut the valve to the heating coil from your C/H unit to prevent thermo-siphoning hot water to the boiler. This is usually adjacent to the cylinder.

Check that you do have a dual immersion element unit fitted for either sink or bath selection and a sink/bath switch to suit . (The sink element is short in length and only heats water near the top of the cylinder).

Switching on half an hour before for sink, or an hour before for bath is usually sufficient. Remember always to switch off after use to minimise heat loss, or fit a timer to do it for you as per the other posts.

yoshytoshy

steamengine wrote: »

Make sure the cylinder is insulated and its a good idea to shut the valve to the heating coil from your C/H unit to prevent thermo-siphoning hot water to the boiler. This is usually adjacent to the cylinder.

Theres no need to touch this valve ,they're usually set by the installer.
The only time syphoning occurs is when it's not piped properly.

steamengine

yoshytoshy wrote: »

Theres no need to touch this valve ,they're usually set by the installer.
The only time syphoning occurs is when it's not piped properly.

Thermo siphoning is quite a common occurrence particularly when the bath water element is in use. I agree this valve is usually in a set position re balancing, but the number of turns to close can be counted eg 1, 2, or 1/2 or whatever and the valve reopened to the same setting.

Probably best to feel the inlet or outlet pipes first to check if thermo siphoning is occurring. There is no point in heating up an idle central heating boiler either.

yoshytoshy

It's not common at all on the majority of heating systems ,warm water rises and this is what creates a circuit.

Most cylinders have there pipes coming up from the floor ,so your not going to have heat rising.
If syphoning is occuring ,then it needs to be sorted out ,because it wasn't piped properly.
I have fixed several jobs were the "plumber" made a balls of pipework and people had no hot water .

If people read this thread and start messing with this valve ,there going to end up with problems when the rads are used again.
For no good reason.

steamengine

yoshytoshy wrote: »

It's not common at all on the majority of heating systems ,warm water rises and this is what creates a circuit.

Most cylinders have there pipes coming up from the floor ,so your not going to have heat rising.
If syphoning is occuring ,then it needs to be sorted out ,because it wasn't piped properly.
I have fixed several jobs were the "plumber" made a balls of pipework and people had no hot water .

If people read this thread and start messing with this valve ,there going to end up with problems when the rads are used again.
For no good reason.

Yes indeed, warm water rises in the cylinder coil and circulates to the boiler, particularly in two storey houses where the boiler is on the ground floor and the cylinder is on the top floor. Can't say it happens in all houses, but certainly in any two storey house I've lived in.

Now, the circulation may not be dramatic, but its a heat loss nevertheless. Yes, you are correct to advise against messing with this valve. At the same time its not exactly rocket science to return a valve to its original positon by counting the number of turns it takes to close it.

yoshytoshy

steamengine wrote: »

Yes indeed, warm water rises in the cylinder coil and circulates to the boiler, particularly in two storey houses where the boiler is on the ground floor and the cylinder is on the top floor. Can't say it happens in all houses, but certainly in any two storey house I've lived in.

Now, the circulation may not be dramatic, but its a heat loss nevertheless. Yes, you are correct to advise against messing with this valve. At the same time its not exactly rocket science to return a valve to its original positon by counting the number of turns it takes to close it.

Look ,it's the internet ,you're always going to be right.