Best Gas Stove Brands & Models for 100m2 Apartment: Viessmann, Junkers, Bosch & More

Hello everyone. I have to install a gas stove, but I don't know anything about it. What company to install the stove: Viessmann, Junkers, Bosch or something else ?? Which model to choose to be trouble-free? What heating power ?? What water tray?
Usable area of 100 m2
The house is made of a 25cm ceramic brick + 15cm foam insulated with polystyrene. Floor heating (living room, kitchen, corridor, bathroom) 60m2. For this 3 rooms (each with a heater).
Two people will live in the house.
I am asking for specific answers what and how to choose. Thanks for any help.

A gas boiler is best one that has a service as close as possible. It's good if it has a low minimum power. The tank is selected according to the actual consumption of hot water and the devices you will be using. If you have a large bathtub or rain shower, the consumption will be large and a larger tray will be needed. It is good for the tank to have an electric heater that, in the event of a gas boiler failure, heats up the water in emergency. Are there any solar panels planned in the future? Then a correspondingly larger tank with an additional coil.

Nobody will tell you anything about the model. Of course you can, but each house is different and you have to put some effort into choosing a specific device.
Go to the website Ciepłow gradwe.pl and fill in the selection of power for the building conscientiously - then you will know what device (power) you need.
The second thing is, do you have access to the site in the area? Whether it's a big city or a small one, it will be hard to find someone.
Has there been a cauldron so far? What? What installation: old, new, from what pipe diameters and what dimensions, what size and "material" radiators?
How's the chimney? Is it possible to use an air-flue gas system for a condensing boiler, what diameters and lengths are available and here you should rather have a chimney sweep opinion.

kankox wrote:

What heating power ??

for 100m2 there is no problem, because boilers with a maximum capacity of 14kW will be sufficient and will have a reserve.
14,000 W / 100 m2 = 140W / m2, and modern buildings require a constant power below 100W / m2 for frosts -20.

Generally, the minimum power of the boiler is important.
Generally, it can be said that the lower the minimum power, the better, because the boiler will be more flexible.
For 2-function boilers, the lowest minimum power is 3-4kW.
In turn, for 1-function boilers, the minimum power is 2-3kW.

If it is a flat, a 2-function boiler is usually considered, i.e. a minimum of 3-4kW.
If the house can be a 1-function boiler, that is minimum 2-3kW, and the maximum will usually be 14kW. As I wrote about what power with reserve and for domestic hot water, it is also OK, because you will have a tank, so you do not need more power, as is the case with instantaneous water heating.

Then you can choose the brand and a specific model that will meet your other needs, but remember not to overdo it with minimum power.
On the market, the range of available powers is large and if you can buy a 1-function boiler with a minimum power of e.g. 2.3kW, I don't see the point in buying a boiler with a minimum power of e.g. 6kW for such a small area, so look at the technical data of the specific model you are looking for. you will watch or someone will recommend you.

Thank you very much for your answers. I thought it was easier with these boilers.
This may give you a hint of which company to buy the stove. What are the low failure rates and if necessary they have cheap parts. The house is near Warsaw, so there will be no problem with the service.

kankox wrote:

This may give you a hint of which company to buy the stove. What are the low failure rates and if necessary they have cheap parts. The house is near Warsaw, so there will be no problem with the service.

Everyone will break sometime. Each one requires an annual service.
Boilers highly rated by the service include: Bosch. It does not criticize other brands. I only resist my own experiences

The failure rate of boilers largely depends on the working environment and the operation of the "pest".
If your water is hard and you don't install a water softening / treatment station, breakdowns will come earlier. E.g. stuck switching valve, pump failure, heat exchanger over time. If you do not install good magnetic separators on the return from the central heating installation - there will also be breakdowns. Most often, pumps.
There is - rather - no such thing that a given company's boilers are more or less emergency.
On the other hand, some parts - subject to wear - such as seals, electrodes - may be more expensive or cheaper.
The first thing - the proximity of the site.
Second thing - minimum power
Third thing - price - BUT
fourth thing - what do you get for the price - and that's BUT it's all about.
fifth point - the price of spare parts subject to wear. For example, a gasket under the burner. Junkers for the WB6 exchanger costs about PLN 55 and you will replace it every 2-3 inspections. For DeDietrich, for example Lumea MPX - it costs 20 PLN - the frequency of replacement - similar.
Set of electrodes - for Junkers with WB6 - about 160 PLN, for DeDietrich - probably about 90-100, because you do not have to replace the set, but the ionization itself.

BUT

There may be a cheaper boiler with similar technical parameters (maximum and minimum power) but with a "poorer" motherboard - and you have to buy some control devices and the cheaper one will turn out to be more expensive.

e.g. You have a boiler, e.g. a clutch and you want to give a second pump after the clutch, which is to switch on with the pump in the boiler when heating the central heating. In Junkers, for example Cerapur SMART - you have such a socket on the disc, and in some Dietrichs you don't. In the cheapest Vaillant EcoTec Pure - also probably not. So you have to buy an additional device, and this is a cost.

Or a circulation pump. You connect to Junkers and select a circulation pump and the boiler will turn it on itself. A small thing, but in terms of "cheap / expensive" it can make a difference.

I have given the above as an example. My point was that you should plan wisely what this boiler is to do and how many heating circuits are to be, as well as triggered ones, etc. Later, look - which of the boilers that meet your criteria with parameters already has built-in control options.

You have a difficult choice ahead of you. Good luck

Well, unless you want to recommend a specific device - then create a poll and we will vote, and you choose the number of votes

Honestly, I don't know anything about it. In my family house, there was a stove for wood, coal, etc. You lit the stove, turned on the pump and kept it in the stove. When the temperature on the stove was too high, the stove closed the air supply flap and that's it. No complications. And here? MAGIC. I read and read and it brightens on average.

I did the calculation. I will be grateful if someone has a look.

Your house needs warmth
The average daily temperature at home throughout the heating season is 22.0 ° C.

9.0kW - the maximum required heating power
On the "coldest" day of winter, ie with a daily average of -20 ° C.

4.4kW - average heating power
This is what you will need on an average winter day, with a daily average of 1.3 ° C.

75W / m2 power demand indicator
This value can be found in the approximate boiler power selection table from its manufacturer. It's just that there it starts from 100W / m2 and above. Interesting, isn't it?

18 680kWh = 67GJ total annual energy consumption for heating
This is how much heat your home needs for the entire heating season. No energy gains are included here.
This is a net amount - as much as the building will accept. Depending on what and with what efficiency you will heat, the amount of gross heat that you need to buy in the fuel will be correspondingly higher.

157kWh / m2 per year energy demand ratio
You will find this value on the building's energy certificate (newer ones have one). Based on this, your house is classified as energy class E

Heating tap water (DHW)
Requirements: for 2 people, Mostly showers, sometimes a bathtub.

3kW additional power needed for domestic hot water heating
It's enough. This is why a large container is placed so that it can be heated slowly, with little power. For a change, flow heating requires a power of over 30kW.

~ 100l boiler capacity appropriate to the needs

What boiler power does the building need?
13kW is the necessary total heating power (CH + DHW)

As for the stove, I would like it not to have to be replaced in 2 years. If I have to buy a cheaper one, but after adding or changing (pump plates it) has a clear exit, as you say, it is better to buy a more expensive one right away and have peace of mind.
The house is a one-story house with the possibility of arranging an attic, but I will not be doing this for now, maybe in 10 years. I will only insulate the ceiling with 20 cm polystyrene and that's it. 60 m of floor tiles in the house.

It calculated for me that 13kW is needed. I found two stoves.
Link
Link
The power should be enough.

And is it possible to buy a stove with a higher output power ??? What is the meaning of the age ??
Link

If you don't have a gas connection, I would seriously consider a heat pump.
And so I recommend a simple boiler termet silver 20kW, which is relatively cheap to buy and service.
in 10-12 years, you will exchange for another one anyway, and this one costs less than PLN 3,000, and it heats the same way as boilers of famous brands, but the service and parts for them will be 50% or more higher than the termet.
It is not a miracle of technology, but it does not aspire to it, especially the price, as some of the 2x more expensive "western" ones, and they break down just like all of them.

I was offered such a set. What do you think about it ???

Regarding the hydraulic system proposed by this plumber / installer. Like 90% of such plumbers / installers, he proposed to connect the heaters with the OP through an OP manifold with a pumping and mixing system based on a valve with a thermostatic head with a capillary. Firstly, such a system is not very suitable for condensing boilers operating at low temperatures, and secondly, such a system does not have OP weather control.
You have ~ 60m2 of floor tiles and ~ 100m2 of the whole house, so most of the area is OP. Controlling it "constant temperature" with this mixing system, you will have either too hot or too cold. You will have to keep flying to the box and adjusting the setting on the head. Complete nonsense! Such systems are proposed by plumbers / installers when they do not want to scare the investor with the price of a correct hydraulic system, where there should be a hydraulic coupling, a pump for radiators and a pump with a mixer for the underfloor heating, and everything is controlled by the automation (additionally extended with appropriate modules) of the boiler.
Either you have to take into account the increase in investment costs to adapt the entire system to the correct solution, or choose one type of heating throughout the building: either only radiators or only underfloor heating. And then the whole should be connected directly to the boiler without couplings, pumps and mixers.

As for the boiler, I have heard opinions that like Viessman, they are worth recommending only from the Vitodens 200 model. I don't know Viessmann and its automation myself, so these are just opinions I heard from people who have and are considering buying a Viessmann.
I know Vaillant boilers and I can recommend the VC 146 / 5-5 boiler from the ecoTEC PLUS series for such a building - the best price / quality ratio in Vaillant. The most cost-effective, of course, in packages with DHW tanks: 120/150/200 l. And a weather regulator and a basic chimney set included.

The case is as I wrote before that I don't know anything about it. The first quote was sent to me here and of course I can ask you what you think. Tomorrow I will be calling other specialists so I will know what others are proposing.