Compatibility of Vaillant Turbotec 20kW Combi Boiler with Galmet Fusion Storage Tank

I have a Vaillant Turbotec 20kW combi boiler. Unfortunately, it does not work well with hot water - it is impossible to bathe in 2 bathrooms at the same time.

After negative experiences with flow water heating - I am determined to buy a tank, but I would not like to buy a new central heating furnace. Will Galmet Fusion work properly with my boiler? Is there any other product on the market that I can connect to my boiler and that will give me the comfort of a storage tank?

Can't seem to connect. Solar panels may be the solution. In such systems, hot water is dangerous with the central heating circuit. This is taken into account in the software and boiler control.

Why can't I connect? The manufacturer on the product page writes: "It has been designed to work with combi gas boilers and take advantage of the natural advantages of layering heated water. Hot water heated in a gas boiler first accumulates in the upper part of the tank from where it is taken to the domestic hot water system. This allows you to draw hot water without frequent start-up of the gas boiler. This solution guarantees significant gas savings and extends the life of the boiler. The waiting time for hot water is also significantly shortened, compared to the use of a gas boiler alone."

It still works on the flow principle. If we assume that the water for use will be taken overnight, e.g. it turns out that the temperature in the tank has dropped so much that it is too cold, then in order to obtain the set value, for example, the entire tank must be poured into the bath.
You can try, but I haven't come across such a solution. On such a rock. There are so-called boilers with warmer Wodyńska comfort, but the tank is small, 30-40 liters, to prevent the boiler from being switched on, e.g. when rinsing a glass.

But if I understand correctly, then there is an additional circulation pump. If the temperature in the tank drops, the water will be heated, right?

I don't know. It's probably like that at the factory. The water is heated to maintain the temperature. And when used a lot, it is heated up to date. The solution may be an electric flow heater. Check what Google says about it. How does this relate to your boiler. Have you asked the manufacturer?

You can connect this tank, but I have not seen it in use anywhere and I do not know how it works. In theory, it looks good. A similar tank is offered by Eutoterm. They also have their 2-function condensing boilers and they also sell them in packages. Biawar also used to offer such a boiler, but they no longer produce it.
Here the principle is that cold water flows into the tank. There is an adjustable HUW thermostat in the tank. If the water in the storage tank is colder than the set point, the charging pump is activated, which forces the flow through the 2-function boiler where cold water is normally connected. The movement of water through the pump forces the boiler to heat HUW (as if we turned on the tap with DHW). The pump works until the thermostat in the tank reaches the set temperature.

There are dedicated tanks for 2f boilers
such, for example, is the SW100 DeDietrich
https://dedietrich.pl/produkty/wyposarzenie/heaters-cwu/sw-100/

The problem may be with hard water, then the plate heat exchanger will scale
I do not recommend doing too much circulation (additional waste of energy)


greetings
Krzyzak11

Lowell wrote:

it is not possible to bathe in 2 bathrooms at the same time.

I have a Vaillant atmospheric 24kW twisted to approx. 17kW and I can easily take a shower in the bathroom + you can turn on the tap in the kitchen and I do not feel any decrease in comfort in the shower, so in theory you can use 2 taps.
Although it actually gives too small flows to talk about fully comfortable 2 showers, but if you are stubborn, you could try something there.
Only I have an apartment, so the cold tap water is warmer than in a detached house, and additionally my boiler is after my private modernizations, so it offers higher comfort than the factory version.

Lowell wrote:

After negative experiences with flow water heating - I am determined to buy a tank, but I would not like to buy a new central heating furnace.

Remember that this works both ways.
If you buy a stratified tank for a 2-function boiler now, then if you need/want to replace the boiler in the near future, the new boiler will also have to be a 2-function boiler.
Otherwise, you will have to buy a new tank with a coil together with a new 1-function boiler.
I rather doubt that the old boiler will last another dozen or so years before you decide that the tank would be worth replacing and then you could buy a new set with peace of mind.

ls_77 wrote:

You can connect this tank, but I have not seen it in use anywhere and I do not know how it works.

Much depends on the options available in the boiler.
There is a comfort feature in my Atmosphere which is ideal for use with a stratified storage tank.
The disadvantage of my boiler is the fact that the hysteresis is constant and amounts to 15 degrees, so if we take 38 degrees as the minimum temperature at which heating will be activated, the target temperature must be at least 53 degrees, which means that the plate heat exchanger will be more exposed to precipitation scale and due to the rigid hysteresis of 15 degrees, the thermal comfort will be the same.
The cartridge will improve something, but the effect can be a bit disappointing.
Unless we will try to use some external thermostat to control the boiler operation cycles in hot utility water mode with lower hysteresis, e.g. 10 degrees, etc.

ls_77 wrote:

A similar tank is offered by Eutoterm.

This is Galmet but sold under the Euroterm brand.

Added after 2 [minutes]:

BUCKS wrote:

I have a Vaillant atmospheric 24kW twisted to approx. 17kW and I can easily take a shower in the bathroom + you can turn on the tap in the kitchen and I do not feel any decrease in comfort in the shower, so in theory you can use 2 taps.
Although it actually gives too small flows to talk about fully comfortable 2 showers, but if you are stubborn, you could try something there.

In my opinion, this is an absolute lack of comfort. First, I turn on the tap, wait God knows how long for hot water (quick washing of hands is always cold), then when the heat is running, when someone else turns on the tap, the temperature drops again. There is no question of ecology at all - you can't take a shower in such a way as to use hot water, turn it off for the time of soaping, and then turn it on again, the water has to pour all the time. Very annoying, hence my search for a tank for this boiler.

Added after 50 [seconds]:

krzyzak11 wrote:

There are dedicated tanks for 2f boilers
such, for example, is the SW100 DeDietrich
https://dedietrich.pl/produkty/wyposarzenie/heaters-cwu/sw-100/

Thanks, that's what I was after. This product looks very good.

Lowell wrote:

In my opinion, this is an absolute lack of comfort. First I turn on the tap, wait god knows how long for hot water (a quick hand wash is always under ice cold),

You will always have the same effect, regardless of whether you heat domestic hot water flowing or with a tank. The only solution to this problem is to install the boiler right next to the tap, but there will always be another tap that will be further away and therefore you will wait longer for hot water. Only hot water circulation will provide the greatest comfort, but it also means an increase in costs if it was to run non-stop, so for this reason some people use circulation activated manually on demand or automatically at certain times if you have a constant daily cycle of using hot water

Lowell wrote:

then when the heat is flowing, when someone else turns on the tap, the temperature drops again.

It's a matter of proper regulation.
If the boiler offers a capacity of, for example, 10 l/min, then the sum of water flows when using 2 taps should not exceed 10 l/min, which gives an average of 5 l/min per one tap.
A minimum of 6 l/min is assumed for the shower to be considered as comfortable.
So for 2 showers you would need a capacity of 12 l/min.

You limit the flow of water, e.g. with aerators with selected flows,
If you have standard aerators, there are no strong ones, but the flows on both taps exceed the technical capabilities of the boiler and hence the cold water.

I usually use one tap, so I don't have a problem. However, despite this, I adjusted the installation so that even with 2 taps there was no problem with cold water in the shower.

Lowell wrote:

There is no question of ecology at all - you can't take a shower in such a way as to use hot water, turn it off for the time of soaping, and then turn it on again, the water has to pour all the time.

At my place, you can turn off the tap for the time of soaping and turn it on after a while.
Only in winter you have to be careful, because if the boiler is heating, turning off hot water means switching to central heating mode and hot boiler water will flow to the radiators, so turning hot water back on means waiting a while, because there will be a wave of cold water and after a while it will be warm again.

When using a 2-function boiler, it is very helpful to understand the idea of how the boiler works, i.e. how the hot water in the radiators and tap is obtained.
It was only when I understood this that I could take conscious and deliberate actions to get the best possible results using the available resources.
The tank increases comfort and when replacing the boiler with a new one, I plan to install a 1-function + tank with a coil, but there is no circulation in my place and at least I am not planning to do a mega renovation to install it. Even so, it's still a comfort for me.

However, with a 2-function boiler, it is also possible to use hot water quite decently, although without circulation, you can forget about washing your hands quickly in hot water. This is where I got used to the cold, so I don't need circulation, because the costs of renovation and its burdensomeness to set up circulation are too big for me to treat circulation as something worth attention.

If someone is doing a general renovation of the apartment, then it is worth installing a circulation system, but after a general renovation, another renovation for the circulation is pointless.

hello, the problem of the creator of the thread has probably been solved, so I'll join in on a similar one
I already have a 300-liter solar-heated tank, I've done it so that I already have a lot of hot water. Well, you only know how the sun is
I am at the stage of setting up gas, choosing a stove and also heating water
Plumbers insist on loading my large tank with gas, because the upper coil heats it up quickly, etc.
I, on the other hand, originally had the idea to buy a stove with instantaneous water heating and power the stove from my large boiler. Then, when I have water from the sun, I don't touch the gases, and when it's there ... let's say 30 degrees, I only heat it up.
Now I'm thinking whether or not to invest in this tank as in the link at the top.
I would give him water from ... then basically a sun-heated buffer.
What do you think?
The initial choice of the oven is duocompact +24 and probably a controller for two circuits (because there are many floors)

I understand that your 300l tank has two coils?
You attach dollars to the bottom and they heat 300 liters of water
You raise the 1f boiler to the upper one and it heats about 120-140l of water. The phenomenon of heat transfer is used here. Hot water goes up.
You receive the controller for the boiler so that you can set the hours of hot water heating
You set them, for example, from 6 to 9 and then from 19 to 23. If solar is not recorded, the boiler is well placed in the upper part of the tank.
At other times the water is cooler (e.g. 40 degrees) but not cold.
Circulation as long as it is limited to a minimum by the timer
Check out Junkers zsb24-5c plus cw400 as long as you have a good service in the area
The Cw 400 performs for you with all of this
Unless you have a solar controller yet, there is also a control module and then the cw400 manages the entire heating system

Okay, thanks for the answer. Yesterday I fought the topic quite intensively and I drew amc25 from de dietrich. It won with extensive automation and deep modulation. And the price is relatively low compared to comparable ones. At least those that I was able to check, although in fact there are so many of these boilers on the market that it is impossible to bite into it.
This five allows me to timer program the heating of the keg.
I think there is much less than half of the top coil in my storage tank. If I remember correctly it's 100 or even 80l.