Immersion timer

I haven't a clue about regs but most timers say in the fitting instructions not to be installed in a hot press. We are not supposed to have most electrical equipment, switches etc near heat. 45amp switches for showers shouldn't be in a hot press. On a positive note for the homeowner, with the timer on the landing you can see easily if it is on or not

The amount of fire traps I see on a weekly basis. Today I saw a fusebox in a press packed tight with clothes.

We are not supposed to have clothes in a hot press. We are probably the only country in the world that does this.

Edit: there is no link to the regs AFAIK. You have to buy a physical copy.

Garvan wrote: »

We're having a new immersion timer installed and we're being told regulations mean it has to be in a visible space, as in on the wall outside the hot press!!!

Have you ever heard of someone leaving the immersion on for weeks? A costly mistake that is unlikely to occur if the switch is outside the hot press. For that reason alone it is a good idea, apart from the fact that it has been a regulation for quite some time.

meercat

This is the relevant regulation
555.6.2 a switching device controlling an immersion heater shall not be located inside an airing cupboard or other similar enclosure

No other electrical equipment (including light) is permitted in a hot press.it doesn't apply to airing rooms that you can physically walk into

555.6.1 electrical equipment in domestic airing cupboards and similar enclosures shall be confined to the following
..An immersion heater and associated wiring but excluding switches
..auxiliary equipment associated with water heating systems

2011 wrote:

Have you ever heard of someone leaving the immersion on for weeks? A costly mistake that is unlikely to occur if the switch is outside the hot press. For that reason alone it is a good idea, apart from the fact that it has been a regulation for quite some time.

Timers are handy where you can see them. Everyone is always under impression they shouldn't leave immersions on all time. I leave mine on 24/7 in the summer and it costs about â‚¬5 a week. I have an extra large cylinder and we bath and shower from that water along with the extra things we use hot water for

jennyhayes123 wrote: »

Everyone is always under impression they shouldn't leave immersions on all time.

I would be in that camp. It is by far the most expensive way to heat water. Electricity will cost about €0.17 per unit where as gas is about €0.06 per unit.

I leave mine on 24/7 in the summer and it costs about €5 a week. I have an extra large cylinder and we bath and shower from that water along with the extra things we use hot water for

I would be interested in seeing the calculation that backs this up.

Heating one cylinder of hot water costs (120 litres) about €1.30 per day. Add to that the fact that the average bath and shower combined will use more than one cylinder of hot water and your €5 per week cost makes no sense even if the insulation on the tank prevents any losses (which is impossible).

2011 wrote:

I would be interested in seeing the calculation that backs this up.

In the winter I top up my meter by â‚¬20 when not using immersion when oil heats water.
In summer I top up by â‚¬25

jennyhayes123 wrote: »

In the winter I top up my meter by €20 when not using immersion when oil heats water.
In summer I top up by €25

Per week, per month, per day? Is it a pre pay meter? Is this an ESB meter or did a landlord install it?
Do you have anything else in the house that uses electricity?

2011 wrote:

Per week, per month, per day? Is it a pre pay meter? Is this an ESB meter or did a landlord install it? Do you have anything else in the house that uses electricity?

Sorry I meant per week.
It's a pre pay electric Ireland meter.
I got it installed. I own the house

There are 6 of us in house. I put on dishwasher 2 or 3 times a day, washing machine, dryer (I use when need, don't ever think can't use cause will cost to much) and electric cooker along with usual tv, phone's, pc, lights etc

jennyhayes123 wrote: »

Sorry I meant per week.
It's a pre pay electric Ireland meter.
I got it installed. I own the house

There are 6 of us in house. I put on dishwasher 2 or 3 times a day, washing machine, dryer (I use when need, don't ever think can't use cause will cost to much) and electric cooker along with usual tv, phone's, pc, lights etc

There is something funny going on so, perhaps a faulty meter unless you have a very small bath and shower

Because each time you have a bath and shower this will consume more water than the tank can hold. Therefore it is impossible to heat that quantity of water with the amount of energy that you are paying for regardless of anything else. So you would save even more if you used proper heating controls which is a rapidly growing industry for a very good reason.

2011 wrote:

There is something funny going on so, perhaps a faulty meter unless you have a very small bath and shower Because each time you have a bath and shower this will consume more water than the tank can hold. Therefore it is impossible to heat that quantity of water with the amount of energy that you are paying for regardless of anything else. So you would save even more if you used proper heating controls which is a rapidly growing industry for a very good reason.

I actually have a very large bath and and large cylinder (bigger than the standard ones so as there is enough water to fill bath (if you want pictures send me your email address and I will forward you on pics)
I have a son who showers twice a day for on average 20 mins unless I shout at him to get out.
My showers take a long time also as I have long hair.
The last house I lived in I did same so it's not a faulty meter. Last house had regular bath and regular tank.

jennyhayes123 wrote: »

I actually have a very large bath and and large cylinder (bigger than the standard ones so as there is enough water to fill bath (if you want pictures send me your email address and I will forward you on pics)
I have a son who showers twice a day for on average 20 mins unless I shout at him to get out.
My showers take a long time also as I have long hair.
The last house I lived in I did same so it's not a faulty meter. Last house had regular bath and regular tank.

The maths is very straight forward. Tell me how much hot water you use per day and how much you heat it by and I will prove to you that you at €5 per week are not paying for the amount of energy that you are consuming regardless of how you are heating the water.

Here is the maths:

If you take the average bath to be 80 litres of water (despite the fact that you describer yours are very large) and a standard power shower to be 120 litres (so only one shower despite the fact that you say your son has two very long showers per day) of water that is a total of 200 litres. See link.

Assuming that the cold water supply is 10°C and it needs to be heated to 60°C that is a temperature increase of 50°C.

The specific heat capacity of water = 4185.5 Joules / litres / °C
Therefore the energy required to heat 200 litres of water by 50°C = 4185.5 x 200 x 50 = 4185,000 Joules

A watt = 1 joule / second

So a 3 kW immersion will deliver 4185,000 Joules in 4185,000/3000 seconds.
This means that it will take a 3 kW immersion 13952 seconds.

A unit of electricity costs €0.17
This is equal to 1 kW of electricity for 1 hour.
Therefore a standard 3 kW immersion will cost €0.51 per hour to run.
Divide this by 3600 and we know that this equates to a cost of €0.000142 per second.
As we know that the immersion will need to be on for 13952 seconds we know that the daily cost = €0.000142 x 13952 = €1.98

This cost assumes no other losses whatsoever (which of course is impossible). So using these figures a bath and shower will cost €13.84 per week and allow no hot water for sinks and the two daily showers that your son has etc..

You can adjust the figures a bit but they would have to change substantially to provide a cost of €5 per week.

coylemj

jennyhayes123 wrote: »

I actually have a very large bath and and large cylinder (bigger than the standard ones so as there is enough water to fill bath (if you want pictures send me your email address and I will forward you on pics)
I have a son who showers twice a day for on average 20 mins unless I shout at him to get out.
My showers take a long time also as I have long hair.

Even if there are people showering and taking baths all day long, there is still heat/energy loss at night when the immersion is switched on. There is no way that you are saving money by leaving it on 24x7, no matter how well the tank is insulated.

If the thermostat kicks in at 2 a.m. and again at 5 a.m., it means that all of the energy used at 2 a.m. was a complete waste. The same is happening right throughout the day when nobody is drawing hot water, the energy and your money is simply floating away into the ether.

2011 wrote:

The maths is very straight forward. Tell me how much hot water you use per day and how much you heat it by and I will prove to you that you at â‚¬5 per week are not paying for the amount of energy that you are consuming regardless of how you are heating the water.

I have never measured how much water I use but there are 3 adults and 3 kids in the house

Gosh how lucky was I in this house and my last house to be able get cheaper than everyone else electricity

jennyhayes123 wrote: »

I have never measured how much water I use but there are 3 adults and 3 kids in the house

Gosh how lucky was I in this house and my last house to be able get cheaper than everyone else electricity

That is one possibility :rolleyes:
Another would be that your information is incorrect because I think the laws of physics will apply just the same in your house as everywhere else

:D

Although 27,000 meters had to replaced as they were found to be faulty so it is not unheard of.

2011 wrote:

That is one possibility Another would be that your information is incorrect because I think the laws of physics will apply just the same in your house as everywhere else

Incorrect in what way? Do you want a copy of my text that show how much I top up by each week?

jennyhayes123 wrote: »

Incorrect in what way? Do you want a copy of my text that show how much I top up by each week?

No thanks. That is one of 3 possibilities I outlined in my last post. Assuming your information is correct what would you say it is?

Perhaps the immersion is on in the winter by mistake so the cost is actually higher. Kids have been know to do this.

Factors that support your theory include: Showers and baths are not very hot, the shower is very weak, your cold water is in fact quite warm.

2011 wrote:

Factors that support your theory include: Showers and baths are not very hot, the shower is very weak, your cold water is in fact quite warm.

2011 wrote:

Perhaps the immersion is on in the winter by mistake so the cost is actually higher. Kids have been know to do this.

The kids don't put on the immersion. It's in my utility room and half way up the wall. They don't go near it.

Why I think it doesn't cost an arm and a leg is because my tank is not usually stone cold, that only happens if we all shower one after another so tank doesn't heat from cold so doesn't cost as much.
Plain and simple and easy as that. No lies or fabrications or whatever else your implying

Maybe you could try it and see it's not as expensive as people think.
Considering I've done this in 2 different houses surely I couldn't be lucky enough to have faulty boxes in both houses

jennyhayes123 wrote: »

Why I think it doesn't cost an arm and a leg is because my tank is not usually stone cold, that only happens if we all shower one after another so tank doesn't heat from cold so doesn't cost as much.

If you have a shower or a bath the hot water used has to be replaced with cold water. This water has to be heated to the desired temperature. The cost associated with this exceeds €5 per week regardless of whether you keep the immersion on or not. It really is as simple as that.

If my calculation is incorrect in post #13 or if you disagree with any of the numbers I have used in that post please enlighten me and I will adjust accordingly.

I am not saying you are dishonest, I am saying that heating that much water by as much as you are should cost more than you are paying.

Karangue

Mod note: If you have something constructive to add to this thread feel free to contribute otherwise don’t post. Thank you.

DublinDilbert

2011 wrote: »

If you have a shower or a bath the hot water used has to be replaced with cold water. This water has to be heated to the desired temperature. The cost associated with this exceeds €5 per week regardless of whether you keep the immersion on or not. It really is as simple as that.

If my calculation is incorrect in post #13 or if you disagree with any of the numbers I have used in that post please enlighten me and I will adjust accordingly.

I am not saying you are dishonest, I am saying that heating that much water by as much as you are should cost more than you are paying.

Did the calculation not assume that the 200L of water is being used @ 60C. The water may be at 60C in the tank but this will be mixed with cold water probably in a 1:4 ratio hot to cold.

So for your 200L bath would only need 50L of warm water at 60-70C, to give a bath temperature of 25-30.

There's alot of variables even the temperature of the cold water in the attic and ambient temperature of the house.

DublinDilbert wrote: »

Did the calculation not assume that the 200L of water is being used @ 60C. The water may be at 60C in the tank but this will be mixed with cold water probably in a 1:4 ratio hot to cold.

So for your 200L bath would only need 50L of warm water at 60-70C, to give a bath temperature of 25-30.

There's alot of variables even the temperature of the cold water in the attic and ambient temperature of the house.

Sure, but this could be offset by the fact that I accounted for one normal shower not two 20 minute showers and I counted one normal bath not a large bath. Add to that that I allowed for no losses whatsoever. Granted my numbers are all estimates but €5 seems impossible to me especially when you consider that prepay generally costs more than €0.17 per unit.

1:4 would be pretty cold IMHO.

Bruthal

jennyhayes123 wrote: »

Why I think it doesn't cost an arm and a leg is because my tank is not usually stone cold, that only happens if we all shower one after another so tank doesn't heat from cold so doesn't cost as much.

But you still have to heat all water used, more often but for shorter times if heated after each shower.

If as an example, you heat it 3 separate times from 55 to 65 degrees after each shower, or a single time from 35 to 65 after 3 showers in a row, the cost will be the same.

DublinDilbert

2011 wrote: »

Sure, but this could be offset by the fact that I accounted for one normal shower not two 20 minute showers and I counted one normal bath not a large bath. Add to that that I allowed for no losses whatsoever. Granted my numbers are all estimates but €5 seems impossible to me especially when you consider that prepay generally costs more than €0.17 per unit.

1:4 would be pretty cold IMHO.

It depends, they €5/week might be the summer cost when the tank in the attic is very warm, so the water going into the bottom of the cylinder is warm. Also the water your mixing with is warm.

I agree €5/week seems to be low, but if a gas boiler was running and heating the tank also the immersion might only be topping up the tank.

DublinDilbert wrote: »

I agree €5/week seems to be low, but if a gas boiler was running and heating the tank also the immersion might only be topping up the tank.

The point is that the boiler is only used in the winter and the immersion is never turned off and this costs &5 per week.

I know I'm not going to prove a scientific equation wrong but I heat my 130 litre cylinder in an hour using the element. I put the cost of heat the 130 litres at around the 1 euro mark. A friend, another plumber, has a smart meter and he believes he's getting 130 litres of hot water for slightly under 1 euro.

Nothing scientific about what I'm saying & I fully admit that the equations prove me wrong but I can see where other posters believe that they are heating water for less than seems likely.

5 euro per week sounds too low even to me. I wonder if maybe someone is using an electric shower rather than a power shower. Electric shower not using hot water from the cylinder would explain how a tank of water is enough for a bath (I'd use the whole cylinder in one bath) and "four showers"?

I believe you, but I don’t think you would be able to fill a large bath and have two twenty minute showers of hot water from one fill of your tank. Even if you could it would cost more than €5 per week.

2011 wrote:

I believe you, but I donâ€™t think you would be able to fill a large bath and have two twenty minute showers of hot water from one fill of your tank. Even if you could it would cost more than â‚¬5 per week.

Look even taking my totally unproven figure of one Euro per tank of hot water it has to be at least seven Euro if it is 7 days. That's just to heat a cylinder, keeping it up to temperature 24 hours per day costs more. I have a 3bar pump. A 10 minute shower would use the whole tank more or less. It costs us 70c to 1 Euro per shower.

Even on my lower figures I'm guessing it has to cost at least 10 Euro (maybe more) per week to leave immersion on 24/7 and having a bath and several showers per day, not to mention washing hands at basin or mopping floors.

Wait till we get our smart meters. It should be a lot easier to judge how much things cost

Talking about meters, they replaced our gas meter. It was only a few years old but the meter reader said it was showing letters instead of numbers. Took about a month cos old meter had to be sent off to be tested but they refunded us some money without being asked. Less than a hundred I think my wife said

whizbang

My shower, on full, uses about 3 litres per minute (with a low flow shower head)

With 2:1 ratio cold to hot water mix, that's 1 Litre per minute of water from the tank.

That's over 2 hours of shower from a full tank.