Thermostatic Mixer with Junkers Gas Water Heater: Can it Improve Hot Water Flow & Comfort?

A question for practitioners and more.

Can a thermostatic mixer be used with a gas flow water heater? I have Junkers for gas.

It is known as "Junkers". After turning on the hot water, you have to wait for warm water to flow to the tap, and after turning it on and unscrewing it again, it starts with hot (heated from the heated up heater) and then it is cold and you have to wait for warm water again.

Will the thermostatic mixer solve at least some of these inconveniences?
Which one to buy? With or without a thermostat?

Such a battery will only help in the fact that you will not burn yourself with boiling water in the following cycles: Junkers heats - Junkers does not heat, or the water is turned on - the water is crazy.

I don't quite understand it.

Does it mean that Junkers turns itself on and off all the time? I mean, it works very unstably?

Does the temperature once set remain the same?

Does it make sense to buy batteries with a thermostat or is it better to buy without? Because as long as it protects it only before the burn it would make no sense to me.

andrzej1771 wrote:

Does it make sense to buy batteries with a thermostat

I believe it's worth it. Although such a battery works better with an electric heater.

It's not worth it and don't try to do it. Junkers has a specific power of min. and max. When it heats the DHW, it works within a certain range of this power. By installing a thermostatic mixer, i.e. by mixing hot and cold water, you will more often cause jumps in demand below the minimum Junker power. Such batteries are not quick to react, they are only suitable for domestic hot water tanks, where the temperature of the flowing hot and cold water is not very variable.

As brofran wrote, you will have alternating very hot and cold even more often than now.

Try not to turn on / off the hot water for a few seconds only when it is going to go.

Also, do not mix hot and cold on the current tap, but set the junker so that there is perfect bathing water on the junker water only. Its temperature, plus or minus 2 degrees, will be controlled by the degree of opening of the tap (as a rule, open water is more open, it should be slightly cooler DHW from a gas heater / boiler)

Now, when the water flies non-stop, not too much open, junkers sometimes turn off?

brofran wrote:

Such a battery will only help in the fact that you will not burn yourself with boiling water in the following cycles: Junkers heats - Junkers does not heat, or the water is turned on - the water is crazy.

boiling water is too strong a term.

My boiler is set to 37 degrees and the water is about 37-38 degrees, but in the first wave it gives full power, it is slightly overheating and the water reaches about 40 degrees.

brofran wrote:

I believe it's worth it.

I think that it is a bad idea with a flow-through heater.

I only turn on the hot water tap, so I have no mixing with the cold water and I see no point in using thermostatic batteries.
If it is with a domestic hot water tank or a boiler, then such a battery makes sense.
Although, in order not to burn yourself, it is enough to provide a thermostatic mixing valve at the output of the boiler and if you set it, for example, 42 degrees, even if there is water in the boiler with a temperature of 80 degrees, hot water with a temperature of no more than 42 degrees will flow to each tap and the problem of scalding we are done.

andrzej1771 wrote:

A question for practitioners and more.

Can a thermostatic mixer be used with a gas flow water heater? I have Junkers for gas.

It is known as "Junkers". After turning on the hot water, wait for warm water to flow to the tap, and after turning it on and unscrewing it again, it starts with hot (heated from the heated heater), then cold and you have to wait for warm water again.

Will the thermostatic mixer solve at least some of these inconveniences?
Which one to buy? With or without a thermostat?

It's worth the most, but only for the shower in my opinion.
I've been using one for 5 years with the gas Junkers on the block. I was also hesitant to buy when I read the good advice "preferably with an electric heater or with the hot water network in the building". I did not have such options, so I bought (SOBIME for PLN 400). It passes the exam without any problems, the water flows from the shower as much as I want.
In the kitchen or at the sink, it will probably not work, because usually the water runs too short for the faucet to set the temperature (unless you wait, but then the water is wasted). But in the cabin as he found.

Stanko2 wrote:

I've been using one for 5 years with the gas Junkers on the block. I was also hesitant to buy when I read the good advice "preferably with an electric heater or with the hot water network in the building". I did not have such options, so I bought (SOBIME for PLN 400). It passes the exam without any problems, the water flows from the shower as much as I want.

from my practice it makes no sense but I have a 2-function boiler with a 20-plate heat exchanger and an additional NTC sensor.
Earlier, when I had a factory 12-plate exchanger and there was no additional NTC sensor for domestic hot water, the domestic hot water comfort was poor and temperature fluctuations were very noticeable.
Each case should be treated individually, so for you, for example, my advice sucks, and for someone else your advice about buying a thermostatic faucet may suck and you will spend PLN 400 unnecessarily.
Apart from that, everyone has their own thermal comfort and this is OK for one person, and for the other it will be unacceptable.

Stanko2 wrote:

In the kitchen or at the sink, it is unlikely to work, because usually the water runs too short for the faucet to set the temperature (unless you wait, but then the water is wasted). But in the cabin as he found.

And in the bathroom, while waiting for the water to reach the desired temperature, water is also "wasted".
In my bathroom, I have to wait at least 30 seconds before the water from the boiler in the kitchen reaches the tap in the bathroom, also without hot water circulation, using hot water to wash the hands is pointless.
But in principle, domestic hot water circulation makes sense when we have a domestic hot water tank, not a flow heater.
Anyway, in my opinion, using a thermostatic mixer with a flow heater is a bit like powdering a muck.
If someone wants to have high comfort of domestic hot water, then the DHW tank + DHW circulation and it will have the best possible variant, of course, then gas consumption increases and you need to have space for a tank, etc., but you have to pay for the comfort.