Heating circuit distributor flushing, circuits do not close completely

Hello,

in our house, our bathroom always has a temperature difference of about -2 degrees compared to the other rooms. So normal room temperature living room 20.5, bathroom 18.5. And this although two circuits are located in the bathroom, one, due to structural conditions, slightly shorter underfloor heating circuit and additionally a wall heating circuit. Our heating has been running for about 1 year now.

I wanted to try flushing this circuit again because I thought there might still be air in the circuit.

For this, I set the water pressure to 6 bar, closed the supply and return of the heating circuit valve, closed all underfloor heating circuits, opened the wall heating circuit, connected fresh water and opened it.

What surprises me is that the flow regulators of the closed circuits also show flow. Not as much as the deliberately opened one, but still noticeably. Even when I closed all underfloor heating and wall heating circuits, water still flowed (into the bucket to which I connected the return for flushing).

My question now is whether this is normal, meaning whether all circuits might be slightly pressed open by the 6 bar, or whether I have a problem here because solid components, such as rust or something, have settled in the closing mechanism of the valves? If yes, what do I do then?

Thanks for the info...

btw: In the attached photo you can see that "Bad W" is fully open, but also for example the closed circuit "Bad F" has flow. You can also see that the water is quite turbid...

opened the wall heating circuit, connected the fresh water and turned it on.

Really bad idea...

[QUOTE="arner, post: 226130, member: 32751"]What surprises me is that the flow regulators of the closed circuits also show flow. Not as much as the deliberately opened one, but noticeably. Even when I have all FH and WH circuits closed, water still flowed (into the bucket to which I connected the return for flushing).[ /QUOTE]

Depending on where you connected something, there can be movement at the regulators... otherwise they wouldn’t make sense.

But about your original problem...

Your bathroom circuit has too little surface area or too large spacing of the heating pipes in the floor, or too low flow.

Hello Mycraft, thanks for your post.

Where is the mistake in my approach? You think it’s a bad idea...

My question or my problem is actually that I find it strange that water flows through the shut-off heating circuits. As I said: Even when I had closed all the heating circuits, the water still flowed. I find that strange. Here is the question whether that is normal.

In hindsight, I really should have laid it tighter in the bathroom. I laid the pipe there, as everywhere else, with a 15cm distance. Due to the structural conditions (installation wall, walk-in shower), it has become less overall. I thought the wall heating would fully compensate for that...

I laid the pipe there with a 15cm spacing as everywhere else. Due to the structural conditions (installation wall, walk-in shower), it has ultimately become less. I thought the wall heating would fully compensate for that...

Far too far apart for a bathroom (unless it is heated sparingly)... unless it is about 20sqm in size... but as your experiences also show... it should have been laid closer together and the wall heating is not sufficient.

You actually have two options now: higher flow rate and/or higher supply temperature.

Your bad idea lies in flushing. Heating systems, especially underfloor heating, require demineralized water and not just fresh water from the tap. That is most likely the cause of the cloudiness you describe.

Hello,

: VE water has nothing to do with FB heating but rather with the heat exchangers in heating boilers. They react allergically to lime-containing water. With a heat pump or old cast iron/wood boilers, this problem does not exist. However, through good lobbying, it is now regulated in VDI 2035-2 how filling water should be. That is why VE water is used even in systems where it is not really necessary. But it also has disadvantages. I researched this for weeks and am still not convinced, even though I have to use reverse osmosis water because I have a condensing gas boiler with an aluminum exchanger. You simply have to test the water and monitor the pH value.

Everything used to be simpler....

Hello,

the heating circuits were also filled with a reverse osmosis system. However, our heating technician said that it wouldn't be dramatic if one circuit were flushed with normal water, as the amount of water is relatively small compared to the total volume.

Best regards!