Electric vs Gas Water Heating: Comparing Junkers, VELIS EVO PLUS 80V & Subscription Fees

Hello, honorable forum members and I am asking you for advice on choosing a water heating system.
Some facts:
I have some old junkers (still with a candle on top), but so far he can do it and during the annual inspections you say that my grandfather will take more. However, I only use gas at home to heat water with this junker and the subscription fees amount to 1/2 of the total gas charges.


I wonder if it would be better to give up gas entirely and switch to heating water with electricity. I've already read a lot about it and the effect is that I'm already crazy. I know that gas is generally cheaper, but won't it be more economical with no gas altogether? When it comes to choosing a boiler, I thought about it: VELIS EVO PLUS 80V.
Technical data:
Capacity: [l.]: 80
Power [kW]: 1.5
Heating time (shower ready) [h: min]: 0:50
Heating time (T = 45oC) [h: min]: 2:15
Daily energy losses (at 65oC) [kWh / 24h]: 1.5
Maximum working temperature [oC]: 80

Supposedly super hyper, learning habits of use etc etc (intelligent - if you can say that about devices). It would fit perfectly in a junker place, so I don't have to do any repairs.
My family consists of 3 people. Generally, 85% of the bath is a quick shower, sometimes the daughter splashes in the bathtub. Hot water is needed at 3 points - a sink, a washbasin, a shower. Dishes are washed by a dishwasher (you know, sometimes a pan is also washed by hand). At the moment, we use 8-10 m3 of water per month. However, how much the hot one actually goes, I have no idea - and here is also the question whether the 80l boiler is sufficient, or maybe large? Water consumption is also one of the arguments for switching to a boiler because a lot of water goes into the waste water waiting for the junkers to heat the water (sometimes it turns on with a delay).
The current electricity bills are as follows:

They are quite tall because I have electric heating. The tariff is G11 and I do not want to change to any night or other ideas. I am not going to wonder if I can turn something on or not, because it is so expensive now.
And that's about it.
Please help and explain if it makes sense to switch from gas to electricity, maybe some other boiler, as the chosen one will work in my case, or maybe do not combine anything and leave it as it is and invest in a newer, better junker?

Best wishes
Paul

renard78 wrote:

I wonder if it would be better to give up gas entirely and switch to heating water with electricity.

And how do you justify it? Because probably not economic?

renard78 wrote:

I've already read a lot about it and the effect is that I'm already crazy.

Sometimes it is enough to pick up the invoice and count it.

renard78 wrote:

Please help and explain if it makes sense to switch from gas to electricity,

Since you say that

renard78 wrote:

The tariff is G11 and I do not want to change to any night or other ideas.

This leaves you gas. Take a look at your invoices. You get PLN 0.22 per kWh of gas. On the other hand, electricity costs 0.45 PLN / kWh. So heating with electricity will cost you twice as much as with gas.
Personally, I am surprised that you heat electrically and you haven't changed the tariff to G12 yet.

renard78 wrote:

I am not going to wonder if I can turn something on or not, because it is so expensive now.

That's what time controllers are for.

The gas one is a terma or a boiler? If the terma, install a gas boiler. Then you don't wait to fire up.

Looking at the forecast gas bill PLN 77 for 2 months, i.e. less than PLN 39 per month, and estimating that about 50% is still hot water, i.e. 4000L per month, the boiler capacity of 80 liters heated in 2h for 1.5kW gives about 150kWh of energy per month to heat the water. 1kWh is about PLN 50, which is about PLN 75 per month. for gas, about PLN 39 per month.

renard78 wrote:

I wonder if it would be better to give up gas entirely and switch to heating water with electricity.

Quote:

And how do you justify it? Because probably not economic?

The convenience of hot water "on the spot" and not waiting for the flow to heat up and pouring the water pointlessly into the sewage. If the costs were similar, I prefer to heat with electricity

renard78 wrote:

I've already read a lot about it and the effect is that I'm already crazy.

Quote:

Sometimes it is enough to pick up the invoice and count it.

The problem is that I do not know what data to take for calculations, such as: how much hot water do I really need for a shower and how often and how long will the boiler work?

renard78 wrote:

Please help and explain if it makes sense to switch from gas to electricity,

Quote:

Since you say that

renard78 wrote:

The tariff is G11 and I do not want to change to any night or other ideas.

Quote:

This leaves you gas. Take a look at your invoices. You get PLN 0.22 per kWh of gas. On the other hand, electricity costs 0.45 PLN / kWh. So heating with electricity will cost you twice as much as with gas.
Personally, I am surprised that you heat electrically and you haven't changed the tariff to G12 yet.

Because I do not heat up at night - I like it to be cold at night.

renard78 wrote:

I am not going to wonder if I can turn something on or not, because it is so expensive now.

Quote:

That's what time controllers are for.

I want to remove the laundry right after drying it, because if I do it after a few hours, I will spend a few hours on the iron.

Added after 5 [minutes]:

jarcecz wrote:

Looking at the forecast gas bill PLN 77 for 2 months, i.e. less than PLN 39 per month, and estimating that about 50% is still hot water, i.e. 4000L per month, the boiler capacity of 80 liters heated in 2h for 1.5kW gives about 150kWh of energy per month to heat the water. 1kWh is about PLN 50, which is about PLN 75 per month. for gas, about PLN 39 per month.

Where did the calculation of hot water consumption of 4000 L come from? I can't believe that if I use 8 m3 of water per month, 50% is hot water. The washing machine or dishwasher takes a cold one, and even in the shower there is also a mixture of hot and cold.

renard78 wrote:

Because I do not heat up at night - I like it to be cold at night.

I understand that you have not heard about storage heaters? :)

I will summarize briefly - if you can afford electric heating in one tariff, you can also afford electric water heating. You will support Polish coal by giving up Russian gas

Krzys55 wrote:

The gas one is a terma or a boiler? If the terma, install a gas boiler. Then you don't wait to fire up.

It is supposed to be a compact device for a small bathroom, are there such small gas boilers that can be installed without a general renovation?

renard78 wrote:

I don't believe that if I use 8 m3 of water per month, 50% is hot water.

Statistics say that hot water consumption is 30-50% of the total water consumption in an apartment.

vodiczka wrote:

renard78 wrote:

Because I do not heat up at night - I like it to be cold at night.

I understand that you have not heard about storage heaters? :)

Quote:

I will summarize briefly - if you can afford electric heating in one tariff, you can also afford electric water heating. You will support Polish coal by giving up Russian gas

And why this sarcasm, I am addressing you as professionals who are able to help in making a decision and it would be nice to get such help without unnecessary gimmicks

No sarcasm, gas carries a greater risk than electricity, the costs of annual gas system inspections are eliminated, the fixed subscription costs are eliminated, which, as you write, amount to almost 1/2 of the total gas costs.
Look logically - if you heat in one tariff, you lose more on it than on a possible switch from gas to electric heating.
You will switch from gas to electricity in two tariffs, you will pay less than today.

Quote:

It is supposed to be a compact device for a small bathroom, are there such small gas boilers that can be installed without a general renovation?

I have a hundred liter junkers and I don't know if they are smaller.

vodiczka wrote:

No sarcasm, gas carries a greater risk than electricity, the costs of annual gas system inspections are eliminated, the fixed subscription costs are eliminated, which, as you write, amount to almost 1/2 of the total gas costs.
Look logically - if you heat in one tariff, you lose more on it than on a possible switch from gas to electric heating.
You will switch from gas to electricity in two tariffs, you will pay less than today.

The problem with storage heaters is that they are larger in size than the electrical panels I have now hung on the wall. I have no place to put another chest of drawers in the rooms or bathroom.

renard78 wrote:

The problem is that I do not know what data to use for the calculations

The first thing you do is look at how much PLN you get on the invoice and divide it by the amount of kWh there. You get a unit cost of PLN / kWh. Then you add additional costs - the cost of inspections, service, replacement of equipment with a new one and you compare, in which case the fixed costs are higher. At the end, you "add" other "unmeasurable" factors, such as ease of use or safety.
In fact, he has summed up everything already @vodiczka - optimal for you would be switching to electricity + plus tariff change to G12. In that case, you would really save a lot.
If you switch to electricity and stay in G11, you will get less than 150 PLN on your bill.

vodiczka wrote:

costs of annual inspections of the gas installation are eliminated,

The electrical installation should also be periodically inspected, especially when heating devices are used, as a rule, they are very powerful. The fact that most people do not do it is another matter ...

Xantix wrote:

The electrical installation should also be periodically inspected,

In housing communities, cooperatives and council flats, it is done every 5 years.

The author of the topic already has an electrical installation and heating a flat requires much more power than heating water in a boiler. Differently with flow heaters - in this case the powers can be comparable.
In both solutions, it should be checked whether the existing installation allows for an appropriate increase in power.

vodiczka wrote:

In housing communities, cooperatives and council flats, it is done every 5 years.

Because that's how the rules are.

vodiczka wrote:

The claim "nobody does" is quite an abuse.

Okay, my mistake - I changed the version.

vodiczka wrote:

The author of the topic already has an electrical installation

Gazowa also has - but what does that have to do with it?

vodiczka wrote:

and heating an apartment requires much more power than heating water in a boiler.

That's right. In my speech, I used the general expression "heating devices".
Generally, I would like to draw your attention to the fact that despite everything, more than half of Poles live in single-family houses, where the sanctioned obligation to inspect installations does not exist. And to my knowledge, it appears that the overwhelming majority of homeowners have this duty to "rub off". Perhaps my statement was an abuse (for which I apologize), but the problem still exists and is significant.

Xantix wrote:

renard78 wrote:

The problem is that I do not know what data to use for the calculations

The first thing you do is look at how much PLN you get on the invoice and divide it by the amount of kWh there. You get a unit cost of PLN / kWh. Then you add additional costs - the cost of inspections, service, replacement of equipment with a new one and you compare, in which case the fixed costs are higher. At the end, you "add" other "unmeasurable" factors, such as ease of use or safety.
In fact, he has summed up everything already @vodiczka - optimal for you would be switching to electricity + plus tariff change to G12. In that case, you would really save a lot.
If you switch to electricity and stay in G11, you will get less than 150 PLN on your bill.

Ok, it costs 1 kWh of electricity for 0.56 grosz, and 0.23 gr for gas.

Not counting the costs of inspection, service or comfort, what data should be taken, how much such a stove will work per day.
Boiler manufacturer data:
Capacity: [l.]: 80
Power [kW]: 1.5
Heating time (T = 45oC) [h: min]: 2:15
Daily energy losses (at 65oC) [kWh / 24h]: 1.5

Assuming that these data are realistic, heating the entire tank to a temperature of about 50 degrees will take about 2 hours (water at the entrance also has a positive temperature), so cost = 3kWh. Maintaining the temperature is much shorter, which is how much to take in the daily consumption. This is where my biggest problem lies. How much such a thing can absorb kWh per day. Someone previously wrote that hot water on the farm is 30-50%. Assuming that we are very economical, 30% is 2400 liters per month, which is 80 liters per day. If it were so, the boiler would use just 3kWh, which gives 3 * 0.56 = 1.68 PLN per day * 30 days is 50 PLN. The bill is issued every 2 months, i.e. PLN 100. It is PLN 22 more than for gas, however, deducting water losses and adding other benefits, in my opinion, I am positive.
But are my assumptions correct ???

renard78 wrote:

Assuming that these data are realistic, it will take about 2 hours to heat the entire tank to a temperature of about 50 degrees

Why, if the manufacturer states:

renard78 wrote:

Heating time (T = 45oC) [h]: 2:15

Up to 50 ° C, rather less than 3 hours. The higher the heated water temperature, the greater the heat loss.
Further, the manufacturer provided:

renard78 wrote:

Daily energy losses (at 65oC) [kWh / 24h]: 1.5

Since you heat up to 50 ° C, the losses will be lower, but in reality you should estimate the energy consumption between 4.5 and 5.0 kWh / day.

To minimize heat loss, I heat the boiler to approx. 42 ° C on the plot, so that the water is warm enough for washing and not to be mixed with cold in the tap.

vodiczka wrote:

renard78 wrote:

Assuming that these data are realistic, it will take about 2 hours to heat the entire tank to a temperature of about 50 degrees

Why, if the manufacturer states:

renard78 wrote:

Heating time (T = 45oC) [h]: 2:15

Up to 50 ° C, rather less than 3 hours. The higher the heated water temperature, the greater the heat loss.
Further, the manufacturer provided:

renard78 wrote:

Daily energy losses (at 65oC) [kWh / 24h]: 1.5

Since you heat up to 50 ° C, the losses will be lower, but in reality you should estimate the energy consumption between 4.5 and 5.0 kWh / day.

To minimize heat loss, I heat the boiler to approx. 42 ° C on the plot, so that the water is warm enough for washing and not to be mixed with cold in the tap.

I assumed that heating to about 50 ° C will take about 2 hours because the water that enters the boiler is not 0 ° C, but a little more, I don't know 7 ° C.
Ok, assuming that the boiler will run about 5kWh a day, without switching to the night tariff, I do not calculate such a device and it is better to stay with gas.
In that case, I will ask another question, what to buy "junkers", or maybe a gas capacitive one, so that the water is warm almost immediately. What do you recommend?
Let me remind you, the place of installation is a bathroom, so the device must be relatively compact.

renard78 wrote:

I assumed that heating to about 50 ° C will take about 2 hours because the water that enters the boiler is not 0 ° C, but a little more, I don't know 7 ° C.

The manufacturer also assumed that the water in the network is warmer than 0 ° C

To minimize heat loss, I heat the boiler to approx. 42 ° C on the plot, so that the water is warm enough for washing and not to be mixed with cold in the tap. If you do not mix with cold, you will use more hot and it will work for one.

Krzys55 wrote:

If you do not mix with cold, you will use more hot and it will work for one

You don't understand what the problem is.
If you turn on the boiler only for the time of washing, it will actually work for one thing
If the boiler is turned on 24 hours a day and maintains the set temperature, the lower you set it, the less energy you will use.

vodiczka wrote:

renard78 wrote:

I assumed that heating to about 50 ° C will take about 2 hours because the water that enters the boiler is not 0 ° C, but a little more, I don't know 7 ° C.

The manufacturer also assumed that the water in the network is warmer than 0 ° C

I read this parameter that raising the temperature by 45C takes 2.15. So if I have a water temperature in the system, e.g. 20C, raising it to 65 will take just that long. And fresh water has, say, 10C, it will come out to 55C for about 2 hours. But I don't know myself there, I use peasant reason

renard78 wrote:

But are my assumptions correct ???

Well, I would count it like this.
You write that:

renard78 wrote:

However, I only use gas at home to heat water with this Junker

So these 340 kWh are also energy consumption for hot water
Now it can be assumed that the old junkers have an efficiency of around 80%. On the other hand, an electric boiler has an efficiency of, for example, 91% - that is, it would use less energy for the same amount of domestic hot water - in this case it would be about 308 kWh. So the electricity for heating domestic hot water would be PLN 140.

I believe that heating water with electricity should only be used where it is not possible to heat water with gas (no gas or exhaust gas draft) or there is no central hot water. The fact that some water is poured in before Junkers heats up is no argument, because these are small amounts of water poured into the sewage system, and besides, when you save water, it clogs the sewage system (I know it well - since my housing estate started to become fashionable to save water, since then sewage failures - clogging). Electricity heating of water is always more expensive and such a boiler has its dimensions and it is a huge weight hanging on the wall (water only 80 kg + boiler weight, so it can be 100 kg). And the time of heating the water in the boiler is a separate problem. When the hot water runs out, you have to wait for it to heat up. Yes, there are also flow water heaters (electric), but they require industrial power supply due to their very high power.

Zbigniew Rusek wrote:

The fact that some water is poured in before Junkers heats up is no argument, because these are small amounts of water poured into the sewage system,

It depends. I know a case where a guest has several taps powered by Junkers and the farthest one is 6 meters from the stove. In this case, 20 liters of water had to be drained into the sewage system before the water warmed up.

Zbigniew Rusek wrote:

Electricity heating of water is always more expensive

But it doesn't always turn out the same in the end. If you want to heat with a boiler in the second zone of the G12 tariff, it will come out only less than 30% more expensive per unit of energy. But adding the costs of the annual Junkers service and the loss of cold water during flow heating before it heats up, the total costs of use will be comparable.

Zbigniew Rusek wrote:

When the hot water runs out, you have to wait for it to heat up.

Therefore, the boiler must be well suited to the needs. So that there is a shortage of water only in exceptional cases.

Zbigniew Rusek wrote:

Yes, there are also flow water heaters (electric), but they require industrial power supply due to their very high power.

It's true - to take a shower comfortably, the flow heater must have 20 kW.

Thank you for all your help and for dispelling doubts.
To sum up, water heating with electrics is only calculated with night (cheaper) tariffs. In other cases, stick to gas, even if 1/2 of the invoiced fees are a subscription.
He stays with his junkers and may he live for the next many years, they say that they do not make such good equipment as they used to. ;)

Regards and I close the topic