Choosing an Efficient 80L Electric Boiler for 2-3 People: Installation, Longevity, and Costs

Hello, I'm undergoing major refurbishment. I am currently looking for an electric boiler for 1 person, but I would like to buy a little bigger for 2-3 people because the number of people living may change.

So yes my idea is an 80L boiler
I found (just a heater) link
or boiler link2

Generally, I need or expect more warm water in the bathroom and kitchen, so the installation would be based on this water heating (shower, sink and sink in the kitchen), I am more interested in efficiency, i.e. that the equipment works as it should for a long period of time (no replacement every year for new) .
I will add that I also do new electrics in the apartment with a view that the boiler will be properly protected so there is no problem with the supply of energy.

24/7 tariff so it makes no difference whether it heats at night or during the day as I work differently.
I hope I have sketched the topic enough, please give me a hint

In general, this heater, and the boiler, is practically the same. Differences - probably in the equipment - one has electronic control, and thus, various setting options. A second, probably ordinary thermostat. The pros and cons have both. I didn't compare prices, because maybe there will be a bigger difference here. It will be cheaper, probably the one with an ordinary thermostat.

The price certainly depends on whether there is electronics or not. The thermostat itself is the simplest and cheapest version. However, a few interesting features for a small price difference will certainly only ask a question about failure, and these two examples I gave only from my search I am open to suggestions of other companies and models.

If the 24-hour tariff is a continuous water heater please. But this requires a lot of power> 18kW. But then you have little heat loss.
If you have a boiler, it offers a G12x tariff - where you will heat water at a cheap tariff (only).

sirfriday wrote:

I will add that I also do new electrics in the apartment with a view that the boiler will be properly protected so there is no problem with the supply of energy.

I do not know what and how you do but I would give the boiler a separate, dedicated circuit only for the boiler and protected it with a separate differential (RCD) and overcurrent fuse.
This increases costs but gives greater system independence. For example, if the boiler activates the RCD, the rest of the apartment will work without a problem and vice versa if something in the kitchen / bathroom initiates a differential, the boiler will work because it will have a separate system with protections, so you increase your confidence in access to hot water.
In the same way I would also connect a washing machine, because a washing machine can sometimes make a difference.

In the same way, divide other rooms into separate circuits and use several separate differentials, because nothing irritates as one differential for the whole apartment and in the event of a failure of one device cuts off the electricity in the whole apartment.
Probably what you will do now will serve you several dozen years, so there is no point in saving too much on materials and equipment, because it is better to have a bit too much in this respect than too little, because then it can be a big problem to add.

As for the tariff, the power plant allows me to change the tariff once a year, so with the boiler for the test you can choose the G12 (day and night) or G12w (weekend) tariff for a year and see what bills you have.
With the G12, you can easily calculate how much you would pay in the G11 (24-hour) tariff, because you add up the amount of kWh, add the appropriate subscription fees according to the price list and you have a comparison to the penny. Depending on the results, after a year you would stay on G12 (day and night) or continue testing by changing to G12w (weekend) or return to G11 (24-hour).
In the case of the G12 tariff, you connect the boiler with a timer, which you program to switch on the boiler only during the "cheap" electricity period. In practice, you will judge for yourself what comfort it offers.

Another thing is that if you are far from the boiler to the kitchen, it may be better to give an 80l boiler in the bathroom, and a smaller one, e.g. 10l for the kitchen. Without so-called DHW circulation, you have to wait a bit before hot water flows, especially if it is a section of pipes from the boiler to the tap in the kitchen that will be several meters long.

In my opinion, the minimum is 50l per one person, the optimal capacity is 100l. If 2-3 people are to use the boiler, it is worth aiming at a capacity of 100-150l. In the case of a large distance between the boiler and the kitchen, you can think of a separate, several dozen liters only for kitchens. In the 24-hour tariff, all "goodies" do not make sense, I would bet on an ordinary mechanical thermostat.

What really distinguishes boilers in the context of operating costs is the quality of insulation. The documentation should say how much energy (degrees) they lose daily, but you have to look in pdf files because producers for "strange reasons" don't want to brag about that. In one of the threads on the electrode there is a discussion on this topic and good insulation can be several hundred annual savings. This parameter is not important only for people heating the bathroom with electricity - the heat that escapes from the boiler will heat it up so the electric heater will consume less electricity and the balance will zero. In our climate there are only 3-4 months when heating the bathroom is not needed so you can afford a boiler losing more heat which compensates for this inconvenience with smaller dimensions.

gaz4 wrote:

the optimal capacity is 100l. If 2-3 people are to use the boiler, it is worth aiming at a capacity of 100-150l.

There is only one thing, but taking into account the size of the apartment, I see the chances at most for a 80l boiler, unfortunately it is not possible to push into every apartment, and where it can be pressed it will be necessary to compromise, which may mean more disadvantages than advantages because of more water.
In addition, a lot depends on consumption. I use about 20l for a shower, also 50l is too much for me.
The quality of the insulation seems to matter, but because of the long breaks during the day, in fact, the more water it is, the better, except that in person I haven't met a boiler over 80 liters.

I used to follow boiler offers and max. hanging capacity was 150l. But in small apartments it can be a problem, however, from what I remember there were a lot of offers around 120l. The larger the boiler, the smaller the external surface in terms of volume, i.e. the smaller the losses. The larger the boiler, the lower the temperature it can be maintained, i.e. we reduce losses again. At least for these two reasons it is worth looking for the largest that can be placed in the apartment. The difference in dimensions 100l and 80l does not have to be big, 100l of the same company is 93 cm high, and 80l 80 cm with identical diameters. The bigger one is about PLN 100 more expensive, and those a dozen or so cm don't make much difference, and 20l of additional water and smaller heat losses are "a plus".

https://www.bojlery.pl/category/bojlery-elekt...hash=54396b89f030ca2dbff4e20abbc39f97&mobile=

If you are renovating, a separate circuit for the boiler socket is recommended. Typical heater power is 1.5 and 2kW. At 2 kW, a separate circuit is required. Differential separately for the boiler in my opinion, no sense. If something is damaged, it should be repaired.
You only need 80 l for 3 people for 3 people, you also need to use it wisely. You raise at a higher temperature and you have more hot water, and more usable time after mixing to 40-45 degrees. You can additionally install a special 3D thermostatic valve on which you can set any constant temperature you expect to prevent e.g. accidental burns.

andrzej lukaszewicz wrote:

Differential separately for the boiler in my opinion, no sense. If something is damaged, it should be repaired.

For me, additional differentials and appropriate circuit layouts mean greater security and reliability in terms of maintaining power continuity.
In short, in the event of a breakdown of a device, e.g. a boiler, I minimize the negative effects of a sudden power outage, limit the size of the zone without electricity, and it's much easier to determine the "culprit", which is not senseless but quite important to me.
I once had 1RCD and failure of one device caused a lack of electricity in the entire apartment and Egyptian darkness.
Then there was an investigation which caused the RCD to break out and as far as I managed it was generally poor comfort of such a solution, so I definitely advise against 1RCD for the whole apartment.
It is hard for me to imagine a situation like grandma staying at home alone, because the rest went for the weekend, and suddenly the cycle and there is no electricity in the whole house, because the RCD broke, and after turning on it still breaks.

If not a separate RCD, only for the boiler, then a separate RCD for the bathroom, because in the case of "we lose" power for the boiler, washing machine, etc., and the kitchen refrigerators work smoothly.
I would definitely give a person a circuit and an RCD dedicated only to the central heating boiler, because this is a key device and here you can not afford the lack of electricity caused by the breakdown of the RCD by another device.

Electrical installation repair is an investment for several dozen years, so it's worth doing wisely. During the renovation, adding an additional circuit or an additional RCD is a small cost, while after renovation such changes mean the need for an additional, relatively expensive renovation, which usually generates greater costs than potential benefits.

If I have a damaged boiler or a washing machine, I remove the plug from the socket and repair / replace the damaged element. According to your thinking, each circuit should have a separate difference because it can break.
I, when making electrical installations, usually give two: for lighting and for + ew sockets, for external circuits (lighting, external sockets, gate automation) and 3-phase ones.
For me, the author can have up to 3 differentials in the bathroom and it doesn't change much about his questions about the boiler. It is more important, for example, to make separate circuits for the boiler and washing machine, and for the socket at the sink. if it has 3-phase power supply and appropriate power allocation, it enables simultaneous heating of water, washing and drying of hair through our "better fishing".
As for the boiler in the bathroom, it's worth thinking about the possibility of draining water from the dropping safety valve, i.e. the drain with a drain to the sewage system with a siphon.

andrzej lukaszewicz wrote:

According to your thinking, each circuit should have a separate difference because it can break.

No, that's not my thinking, you don't understand what I mean or you don't want to understand and you draw the wrong conclusions.

If you want to have 1RCD on all sockets in the whole apartment is your choice.

During renovation, not everyone thinks and takes into account all variants, so it's worth to signal different options, because then it is usually too late for such changes. And everyone will apply this solution that will meet their needs, so long as it was a conscious decision, not a decision caused by a lack of insight into the subject and lack of full information or full advice from the contractor, etc.

BUCKS wrote:

sirfriday wrote:

I will add that I also do new electrics in the apartment with a view that the boiler will be properly protected so there is no problem with the supply of energy.

I do not know what and how you do but I would give the boiler a separate, dedicated circuit only for the boiler and protected it with a separate differential (RCD) and overcurrent fuse.
This increases costs but gives greater system independence. For example, if the boiler activates the RCD, the rest of the apartment will work without a problem and vice versa if something in the kitchen / bathroom initiates a differential, the boiler will work because it will have a separate system with protections, so you increase your confidence in access to hot water.
In the same way I would also connect a washing machine, because a washing machine can sometimes make a difference.

I wrote above, I did not specify the fact. But the electrical installation will be made for years and as it should separate circuits will fly, I was thinking about the washing machine but decided that there is no need. In the bathroom, only the boiler and washing machine from electrical appliances, the rest are sockets for razors and other bullshit.

So I can confidently write that gentlemen's electricity is OK. Thank you for the signals, but I planned the renovation of the apartment "wisely" so as not to have such problems and I try to do everything for years without saving.

However, now I have a dilemma about the boiler because I still haven't heard specific answers to the question.
Tomorrow I am going to the supermarkets to ask "professionals" castoramas etc. what they will offer me but I hope that I will get answers or hints here so that I can talk to this "specialist" a bit about.

The initial assumption is a 80 l boiler because it is for 1 person (max 3 people but occasionally), a small apartment and a small gap between the bathroom (where the boiler) and the kitchen. So it also doesn't make sense for 3D valves.

The question is what brand of power what something solid would last for years.

The durability of the boiler depends on the water quality and pressure in the installation. The most commonly used safety valves with a check valve are the minimum required protection of the boiler, but unfortunately they force the tank to work with a maximum pressure of 6 bar-opening pressure. This situation occurs only when all hot water is selected and the entire tank is heated. Then the greatest stress occurs in the tank and micro cracks in the protective enamel.
I would assume theoretically such criteria as: a product of a well-known brand on the market for years, relatively the largest weight at the same capacity (wall thickness) and tank insulation thickness (less stoppage loss). The aesthetics of the workmanship, ease of access to the heater, anode, suspension method etc. are also important.

Anyone who has done on the site will say that putting only on a brand (even a good one) is pointless. One of the worst car radios I put in was produced by Sony (it had more certificates than it was worth), and on Panasonic's radio I found such an obvious structural error that even a 1st grade technical technical student would have caught it. In the first place I would bet on technical parameters, and only later looked for boilers that would meet them.

1) The quality of IMHO insulation is crucial because it will affect operating costs. Unfortunately, this information is difficult to find, producers will "cheat their eyes" with some clichés.
2) The heater power in the case of boilers in the 80-120l range used in the 24-hour tariff does not matter much because 1.5 and 2.5 kW will cope perfectly. Simply any, even the smallest water consumption will cause the temperature to drop, the thermostat will activate and heat up.
3) When it comes to durability, it should be remembered that the higher the water temperature in the boiler, the more stone, so the less durability. This is another reason to be interested in as much capacity as possible. And if the boiler temperature is around 50 degrees, we will limit limescale, the risk of burns equal to zero, so you do not need additional mixing valves, and after exceeding 50 degrees ceases to multiply.

wnoto wrote:

If the 24-hour tariff is a continuous water heater please. But this requires a lot of power> 18kW.

Such power requires adaptation of the electrical installation to such a high load. It must always be a 3-phase supply.

gaz4 wrote:

Anyone who has done on the site will say that putting only on a brand (even a good one) is pointless. One of the worst car radios I put in was produced by Sony (it had more certificates than it was worth), and on Panasonic's radio I found such an obvious structural error that even a 1st grade technical technical student would have caught it. In the first place I would bet on technical parameters, and only later looked for boilers that would meet them.

1) The quality of IMHO insulation is crucial because it will affect operating costs. Unfortunately, this information is difficult to find, producers will "cheat their eyes" with some clichés.
2) The heater power in the case of boilers in the 80-120l range used in the 24-hour tariff does not matter much because 1.5 and 2.5 kW will cope perfectly. Simply any, even the smallest water consumption will cause the temperature to drop, the thermostat will activate and heat up.
3) When it comes to durability, it should be remembered that the higher the water temperature in the boiler, the more stone, so the less durability. This is another reason to be interested in as much capacity as possible. And if the boiler temperature is around 50 degrees, we will limit limescale, the risk of burns equal to zero, so you do not need additional mixing valves, and after exceeding 50 degrees ceases to multiply.

So, following these steps, are you able to recommend something specific to me?

Nothing specific can be recommended because everyone has specific requirements, and boiler manufacturers like ants. At the beginning of the 90s I wanted to buy a boiler with a max 1.5 kW heater because I did not want it to overload my old installation. As for all angers, all boilers> 50l had 2 kW, it was only in the last store where I came without hope of purchase that I came across the ideal: Elektrolux 60l with 2 heaters 0.8 kW each + switch. Normally he worked on 1 heater, heating it to 50 degrees, only when I had to "drive" it turned on full power. One of the heaters burned out after about 10 years of work, and the other after almost 20 years. Heaters could be replaced without draining the water from the boiler, but this solution is a disadvantage. It simply hinders the transfer of heat to water, so the risk of heater burnout increases.

In my opinion, you should look at the quality of insulation, I do not think that the manufacturer who saves on everything while doing trash, warmed the boiler well. Unfortunately, this requires tedious browsing of the user manual because only there is this information.

I think the topic is exhausted enough and I would like to close it.