Immersion heater on long period during night

fluppet

I have a 'Gold Shield' home which came with a Horstmann Economy 7 Quartz immersion heater controller. According to ESB's documentation it is supposed to heat the water from 3:30 am to 7:30 am. I believe this is what it does, but it seems like quite a waste of electricity to have it almost continuously heating the water for 4 hours every night.

Between 3:30 and 7:30 you can hear it maintaining the water at the thermostat setting (50 C) - it heats it, then shuts off for a few minutes, then heats it again, on and on for 4 hours.

Is this normal? As it is a 'Gold Shield' home, the tank has a coating (lagging) on it that was applied at the factory. Shouldn't it only heat up the water first at 3:30am and then the water should stay approximately at that temperature for quite a while, before eventually dropping below the trigger level and so it will get heated-up again - but this should only happen a few times over the four hours, rather than almost continuously.

I have twin immersion heaters (one is connected near the top of the tank and the other near the bottom of the tank). My understanding is that the lower heater is used for the normal night-time heating, and the upper heater is used for if I put on the boost. A few years ago I had to have the lower heater replaced. I am not sure whether the situation was different before it replaced.

According to the documentation for the Horstmann control the thermostat of the upper heater should be set lower than the thermostat of the lower heater. I have them both set at 50 C, but I believe this is not related to my problem - the only consequence I can see is that the water would be a bit hotter from 'boost' than timed heating.

ircoha

fluppet wrote:

I have a 'Gold Shield' home which came with a Horstmann Economy 7 Quartz immersion heater controller. According to ESB's documentation it is supposed to heat the water from 3:30 am to 7:30 am. I believe this is what it does, but it seems like quite a waste of electricity to have it almost continuously heating the water for 4 hours every night.

Between 3:30 and 7:30 you can hear it maintaining the water at the thermostat setting (50 C) - it heats it, then shuts off for a few minutes, then heats it again, on and on for 4 hours.

Is this normal? As it is a 'Gold Shield' home, the tank has a coating (lagging) on it that was applied at the factory. Shouldn't it only heat up the water first at 3:30am and then the water should stay approximately at that temperature for quite a while, before eventually dropping below the trigger level and so it will get heated-up again - but this should only happen a few times over the four hours, rather than almost continuously.

I have twin immersion heaters (one is connected near the top of the tank and the other near the bottom of the tank). My understanding is that the lower heater is used for the normal night-time heating, and the upper heater is used for if I put on the boost. A few years ago I had to have the lower heater replaced. I am not sure whether the situation was different before it replaced.

According to the documentation for the Horstmann control the thermostat of the upper heater should be set lower than the thermostat of the lower heater. I have them both set at 50 C, but I believe this is not related to my problem - the only consequence I can see is that the water would be a bit hotter from 'boost' than timed heating.

Cant help on the timer: much has been written on it eslewhere on this forum: however 50 is too low: min is 60
see http://www.amm.co.uk/files/factsabout/fa_leg.htm

fluppet

Thanks for the info - I never thought about that... I moved it down from 60C to 50C a few months ago to see if it would have any effect on my electricity bills.

Anyway - I can see two possible causes of my problem - the first is that heat is leaking out somehow, so the temperature of the water drops below the 'trigger' level of the thermostat quickly and it starts heating it again until it reaches 50C (soon to be 60C again).

The second possibility that I can see is that perhaps the 'lower trigger' (the highest temperature at which it will start heating the water) on the thermostat is set too close to the 'upper trigger' (the lowest temperature at which it will not heat the water).

Does anyone else notice their immersion heater cutting in and out many times every night?

Hagar

Here's the type of immersion heater in common use in France. It's an always-on thermostatically controlled unit, mine is set to 65. The insulation is so good that you can touch any part of the tank skin and feel no heat whatsoever. Because of that they are cheap to run. If I were building in Ireland I would get one of these brought in, it would pay didvidends in the long run.

10-10-20

fluppet wrote:

Between 3:30 and 7:30 you can hear it maintaining the water at the thermostat setting (50 C) - it heats it, then shuts off for a few minutes, then heats it again, on and on for 4 hours.

You could either have a low hysteresis (difference between the high and low) on the thermostat, or a loss of heat, or this could be a fact of life. Mine cycles on and off approx every 15 mins when left on 'sink', but I don't have an insulation problem.

Is this normal? As it is a 'Gold Shield' home, the tank has a coating (lagging) on it that was applied at the factory. Shouldn't it only heat up the water first at 3:30am and then the water should stay approximately at that temperature for quite a while, before eventually dropping below the trigger level and so it will get heated-up again - but this should only happen a few times over the four hours, rather than almost continuously.

What I suspect could be happening is that the colder water at the bottom is mixing with hotter water at the top due to flows or currents inside the tank.
Check the insulation on the tank to determine if you have any hot-spots and also look at the lagging on the pipes from the top of the cylinder. This is where the heat loss will be concentrated.

Reyman

fluppet wrote:

Iting the water for 4 hours every night.

Between 3:30 and 7:30 you can hear it maintaining the water at the thermostat setting (50 C) - it heats it, then shuts off for a few minutes, then heats it again, on and on for 4 hours.

If you're heating up a full tank of water for 4 hours during the middle of the night you're certainly wasting electricity and money. It usually takes around an hour to heat the full tank (30gal) and 10-15 mins to heat up the top section (5 gals).
I'd reset the timer to use the 'sink or top immersion' timer a half hour before I get up in the morning. You should manage two showers with this.
You hardly need 30 gals of hot water in the morning - do you? If you do - set it for an hour before you get up (within the cheap electricity times)

mukki

i'd leave it at 50,
washing your hands with a litre of water from the hot tap would be more comfortable and have costed less to heat
also heat loss is porportional to temperature difference, so the colder it is the slower it will cool



if your not running out of hot water during the day then just stop listening to it

GreeBo

mukki wrote:

i'd leave it at 50,

and welcome in the legions of baddies?:rolleyes:

mukki

GreeBo wrote:

and welcome in the legions of baddies?:rolleyes:

sarcastic smiley is good when you "pretend" to agree with someone :mad:


try

GreeBo wrote:

yeah, i'd love to welcome in the legions of baddies?:rolleyes:

(you can also use the scartastic smiley by saying something deliberately wrong)

yeah, there is a good chance of bacteria build up on a sealed tank of chlorinated water :rolleyes:

there is no chance the the baddies will happily live in the unheated bottom part of the tank :rolleyes:

water doesn't have to be heated about 85 to kill bacteria :rolleyes:

the op posted worying about bacteria in his tank and not about his fear that he was wasting electricity :rolleyes:



or..............

next time try to post something like this

GreeBo wrote:

be warned that not heating the water above 60o may cause bacteria build up in the tank

there that is much better, no point attacking a post by someone who is trying to help, and if you noticed he already had the tank set to 50o


and finally

GreeBo

mukki wrote:

sarcastic smiley is good when you "pretend" to agree with someone :mad:

and rolling your eyes [up to heaven] is good when you think someones suggestion is a silly idea especially when someone else already pointed it out in the same thread.

Thanks for reading the whole thread before responding.:rolleyes:

mukki

GreeBo wrote:

and rolling your eyes [up to heaven] is good when you think someones suggestion is a silly idea especially when someone else already pointed it out in the same thread.

Thanks for reading the whole thread before responding.:rolleyes:

no harm denfending yourself, but stop being all cheeky when you proved yourself right


christ, i'm only trying to help

never heard of anyone getting that legionairs crap (missed that link earlier)

podge018

what time exactly is the off-peak? My water heater does be still on when I leave for work around 8.30am.

GreeBo

podge018 wrote:

what time exactly is the off-peak? My water heater does be still on when I leave for work around 8.30am.

Unless you specifically sign up for Nightsaver all your electricity costs the same irrespective of when its used.
However, its better for the environment if you can wait until off peak times for your high energy items (washers, dryers, etc)

magicbastarder

Hagar wrote:

Here's the type of immersion heater in common use in France. It's an always-on thermostatically controlled unit, mine is set to 65. The insulation is so good that you can touch any part of the tank skin and feel no heat whatsoever. Because of that they are cheap to run. If I were building in Ireland I would get one of these brought in, it would pay didvidends in the long run.

i'm still not sold on this concept. let's say the volume of hot water you need in a day can be provided in half an hour by the immersion; say, for the sake of argument that you leave the immersion on for 45 minutes to get this, in a typical immersion. 15 minutes of wasted heating.

in the system mentioned by hagar, assuming 100% perfect insulation, the immersion would come on for half an hour a day.
i would have assumed that the fact that the insulation is not going to be 100% perfect would make up more than 15 minutes of catchup time for the immersion over the course of the other 23.5 hours; for example, if the immersion had to come on for one minute every hour, assuming no use of hot water, to make up for heat loss, the always-on system would be less efficient than the 'traditional' model with the above figures.

Hagar

FWIW our electricity bill is less than €60 per month and we use electricity for cooking and heating/cooling*.


* Sorry I couldn't resist that. It's 9:30pm and 21C.

10-10-20

magicbastarder wrote:

i'm still not sold on this concept. let's say the volume of hot water you need in a day can be provided in half an hour by the immersion; say, for the sake of argument that you leave the immersion on for 45 minutes to get this, in a typical immersion. 15 minutes of wasted heating.

in the system mentioned by hagar, assuming 100% perfect insulation, the immersion would come on for half an hour a day.
i would have assumed that the fact that the insulation is not going to be 100% perfect would make up more than 15 minutes of catchup time for the immersion over the course of the other 23.5 hours; for example, if the immersion had to come on for one minute every hour, assuming no use of hot water, to make up for heat loss, the always-on system would be less efficient than the 'traditional' model with the above figures.

These things are the dogs nuts. They are efficient because the piping is encapsulated in the external shell and are surrounded in wads of foam.

Look - 100l wall mounted tanks for €199 upwards...
http://www.leroymerlin.fr/mpng2-front/pre?zone=zonecatalogue&idLSPub=1055423690&1055421829.idnode=1064425818&02-multicritere-render=off&01-comment-choisir-render=on&03-zoom-produit-render=off&03b-mise-en-avant-produits-render=off&04-selectionne-pour-vous-render=off&09-Q2Q-render=off&nli=29&05b-voir-aussi-famille1-render=off&05c-voir-aussi-famille2-render=off&05d-voir-aussi-famille3-render=off&05e-voir-aussi-univers-render=off&05f-voir-aussi-ss-univers-render=off&06-liste-conseils-famille-render=off&07-livres-famille-render=off&08-liste-idees-famille-render=off
It also says that the water is retained at temperature for 5hrs30 mins.

The only reason we don't use the in Ireland is because we are accustomed to having a cylinder in a hotpress. Apparently houses don't sell in Ireland if they don't have a hotpress.

Hagar

That's true, not hotpress just hot water.

Hagar

Duplicate posts again sorry about that.

podge018

GreeBo wrote:

Unless you specifically sign up for Nightsaver all your electricity costs the same irrespective of when its used.
However, its better for the environment if you can wait until off peak times for your high energy items (washers, dryers, etc)

Im on nighsaver - my night units are half the price of my day units. So, what are the times?

10-10-20

Have a look in your consumer box (ask ESB Networks for a key) and you'll find the day/night timer. It will show the settings.

paulb

Midnight to 8 a.m. during Summertime (last Sunday in Ocober) after that 11 pm to 7 a.m..

There is a higher standing charge for Nightrate electricity but obviously a lower unit charge.

PaulB

podge018

There's a problem so if mine does be still on at 8.30ish