Title: Electric Boiler for 2-Person Shower: Are 50L Models Enough? Tips, Recommendations & Brands

I do not approach this issue in terms of calculations, but these 40 liters are enough for me and for someone else it may not be enough and this is a very correct remark with which I fully agree.
I know one thing, however, that making the boiler in terms of thermal insulation is the basis because having the previous boiler with a capacity of 60 liters, I could not wait for it to leak and need to be replaced. The previous boiler was turned on every 10-15 minutes, even when there was no water consumption and the electricity bills dropped significantly after replacing it with a new one.

Kenworth 18 wrote:

I do not approach this issue in terms of calculations

If you are satisfied with what you have, you do not have to count anything, except for learning purposes.

But when planning the purchase of a boiler, such calculations allow to estimate whether a given tray will be OK for our current needs.
The results may indicate whether and to what extent you will need to change your current showering habits, etc.
Before that, it is worth doing a test and see how many liters of water are used on average for one shower and how many liters of hot water per minute can be flown through our faucet used during a shower.

Added after 2 [minutes]:

Kenworth 18 wrote:

The previous boiler was turned on every 10-15 minutes, even when there was no water consumption and the electricity bills dropped significantly after replacing it with a new one.

In such cases, it may be a matter of a damaged thermostat, because it controls the heater's activation cycles and sometimes replacing the thermostat with a new one can completely change the boiler's operating characteristics.

For me, 30 liters is enough for one person. After less than half an hour, the boiler heats up again (depending on how much water was used by the previous person). I mix water with cold water anyway, because it is a bit too hot from the boiler. If I had set the temperature just for washing, maybe at the end of washing it would be too much mixed up with the cold. My water is also not very hot, so that someone gets scalded by mistake. In any case, I try not to waste water and it is not about the price of it.

I am going to buy such a boiler, it has protection against the formation of bacteria (it raises the temperature itself once a month) And as for losses, etc., I am attaching a photo ... 30 minutes before each shower.

loli1987 wrote:

I am going to buy this boiler.

So 50 l has about 41.3W of standing losses, and the 80 l model has 56.3W for water with a temperature of 65 degrees.
In other words, if there is no domestic hot water consumption, in theory 50 liters of water will cool down by about 17 degrees per day, and 80 liters of water will cool down by about 14.5 degrees.

According to the technical data, the daily difference is 0.36kWh, which per year gives 131.4kWh of additional energy as part of the standstill losses for the 80-l model. The difference is, for me, not a significant difference to disqualify the 80-l model.

loli1987 wrote:

It is protected against the formation of bacteria (it raises the temperature itself once a month)

bacteria multiplication is a matter of a few days, therefore it is customary to steam the trays once a week, not once a month.
Of course, it all depends on the temperature you will keep in the tank, because the problem of legionella increases the lower the water temperature in the boiler.

loli1987 wrote:

And I think I would switch to g12as and it would heat up just before the end of the cheaper rate and then 30 minutes before each shower.

a good thought, but in practice you would have to test how long it takes to heat up the water in the boiler, then you would have a reference point at what time to turn on the heaters so that the heating process ends just before 6. At the beginning, make yourself tests to see if you have enough hot water without reheating 30 min. before each shower, because you may not have to reheat the water during the day, if you choose the 80 l model.
If you have too high water flows in your tap, you can use aerators with a flow of approx. 8 l / min. Less flow means less water used, and the flow of 8l / min is still a comfortable flow for the shower. For the tap, you have a typical aerator, and for the shower, there are special reducers mounted at the joint of the shower hose and tap.

And so I think I will. I have just watched those pertrators that have a flow of 6l / min. Always 2 liters of savings (although they say savings of 10l on the website) because an ordinary handset lets through 16l .. I am waiting for an e-mail from ENERGA regarding changes in the tariff and price list.

Well, the important issue of flow has been raised. I just did the test because I was always irritated by the time of pouring e.g. a bucket of water into the mop and it turned out that it was quite right. It took 1m 5s to fill a 5 liter tank with a GROHE hand shower. Maybe this is where the saving comes from. As for the maximum temperature, this setting in the boiler is 85 ° C.

@ loli1987
As for aerators, you have to buy and check whether the resulting stream of water will satisfy you. Otherwise it cannot be verified.
I bought Neoperl aerators for my gas boiler, they were not the cheapest, but I did not regret the PLN 20 and I am satisfied.

@teskot
Water flows are essential.
If you have a real capacity of approx. 5 l / min, then after mixing hot and cold water, you have a correspondingly lower consumption of water from the boiler, and this certainly has an impact on domestic hot water consumption and costs.

I check the flows on the water meter by recording a video on the phone, thanks to which I can measure consumption within 60 seconds with an accuracy of 0.05 liters, so you can notice small fluctuations and differences that are not visible when filling the vessel.

Will such an aerator, which is mounted on the hose to the handset right next to the tap, reduce the water pressure in the handset?

I have an aerator as an extension of the hose with a capacity of 8l / min and I do not complain. Yes, you can see the difference in the water stream with the naked eye, but it is still at an acceptable level. I heat the water through flow and on the tap water system I have a maximum of 2 bar, i.e. I can unscrew the cold water supply to the boiler to the central heating system and on the boiler I will not get more than 2 bar, so I will not even shoot the safety valve.
With a boiler you have such a home water tower, so I wouldn't worry about serious drops.
As for me, 8l / min aerator can be taken blind and you should be satisfied, as for the weaker performance aerators, you have to buy and check if the results will be satisfactory for you.
In the kitchen I have an aerator with a capacity of 6l / min and it is OK, although the actual flows are a bit smaller than the catalog ones.

In that case, I found out what I wanted. Next week I am starting a renovation, so in about a month I will write what and how it came out. And in the further operation of the boiler, I will write how much water is used and what the bill came out for future inquiries. Thanks ....

I know that I should write a new topic in another section, but the matter applies to the boiler referred to in the topic.
Renovation is in progress and I faced a dilemma whether to take 50l because it is lighter and the wall is in a dilapidated condition in the place where it will hang. In the attachment I am sending a photo of where the boiler is to be installed. url = https: //obrazki.elektroda.pl/5294439400_1569407004.jpg] [/url]
I will scratch off the joints a little and I do not know whether to seal it with mortar or glue for gypsum boards. The fastening will be for chemical anchors with a 15 cm long threaded rod. Will it be able to withstand it?

This is a very bad condition of the wall and it is almost certain that it will not support the weight of the boiler (even a 50 liter boiler). If something so heavy is to be hung, the wall would have to be renovated. These anchors will not be able to sit well in this.

How much space do you have to the ceiling? What's on the other side of the wall?

As you can see the groove above the bricks, the ceiling will be there (it is lowered because it is now 3.75m). On the other side there is a staircase. So far, the fixing is in the middle of these bricks.

Added after 7 [minutes]:

This is what it looks like.

it looks to me as if there was a window once and then a niche was made in which now you can see a shelf with household chemicals.
As for me, this pseudo-cabinet is a setback and the recess should be filled with bricks to stiffen the structure.
Fixing in the middle of the bricks is too close to the edge for me, and I would not like to collect the boiler from the floor, because it might kill someone on the occasion.
I am an amateur and this is my private opinion based on my intuition after analyzing the visible photos.

This is the recess after the door to the staircase. On the side of the staircase, 12 cm bricked in brick. In this recess, 12 cm wooden beam reinforcements will be inserted, attached to the wall with angles so that the boiler has something to rest on. Then plasterboard.
I am thinking of giving such a reinforcement made of thick sheet metal and chemically anchoring 6 threaded rods (black points). The red points are the place where the boiler is attached. In this recess, the beams I wrote about above.

However, it will be 50 liters. One shower less a day (one household member moves out), so 80 liters will be too much.