Hello,
In our house, the bathroom consistently has a temperature about 2 degrees lower than the other rooms. For example, the normal room temperature in the living room is 20.5°C (69°F), while the bathroom is 18.5°C (65°F). This is despite having two circuits in the bathroom: one floor heating circuit that is somewhat shorter due to structural conditions, and an additional wall heating circuit. Our heating system has been running for about one year.
I wanted to try flushing this circuit again because I thought there might still be air trapped in the circuit.
For this, I set the water pressure to 6 bar (87 psi), closed the supply and return at the manifold, shut off all floor heating circuits, opened the wall heating circuit, connected fresh water, and turned it on.
What surprises me is that the flow meters on the closed circuits are still showing some flow. Not as much as the intentionally opened one, but noticeably nonetheless. Even though I closed all floor and wall heating circuits, water still flowed (into the bucket connected to the return for flushing).
My question now is whether this is normal—could the 6 bar (87 psi) pressure be causing all the circuits to open slightly—or do I have a problem where solid particles, such as rust, have settled in the valve closing mechanism? If so, what should I do then?
Thanks for the information...
By the way, in the attached photo you can see that the "Bad W" (bathroom wall heating) is fully open, but for example, the closed circuit "Bad F" (bathroom floor heating) also shows flow. You can also see that the water is quite cloudy…
In our house, the bathroom consistently has a temperature about 2 degrees lower than the other rooms. For example, the normal room temperature in the living room is 20.5°C (69°F), while the bathroom is 18.5°C (65°F). This is despite having two circuits in the bathroom: one floor heating circuit that is somewhat shorter due to structural conditions, and an additional wall heating circuit. Our heating system has been running for about one year.
I wanted to try flushing this circuit again because I thought there might still be air trapped in the circuit.
For this, I set the water pressure to 6 bar (87 psi), closed the supply and return at the manifold, shut off all floor heating circuits, opened the wall heating circuit, connected fresh water, and turned it on.
What surprises me is that the flow meters on the closed circuits are still showing some flow. Not as much as the intentionally opened one, but noticeably nonetheless. Even though I closed all floor and wall heating circuits, water still flowed (into the bucket connected to the return for flushing).
My question now is whether this is normal—could the 6 bar (87 psi) pressure be causing all the circuits to open slightly—or do I have a problem where solid particles, such as rust, have settled in the valve closing mechanism? If so, what should I do then?
Thanks for the information...
By the way, in the attached photo you can see that the "Bad W" (bathroom wall heating) is fully open, but for example, the closed circuit "Bad F" (bathroom floor heating) also shows flow. You can also see that the water is quite cloudy…
arner schrieb:
I opened the wall heating circuit, connected the fresh water supply, and turned it on.Really bad idea...
arner schrieb:
What surprises me is that even the flow regulators of the closed circuits show some flow. Not as much as the one deliberately opened, but still noticeable. Even when I closed all floor heating and wall heating circuits, water flowed through (into the bucket where I connected the return line for flushing).Depending on where you connected something, there can be movement at the regulators... they wouldn’t work if they were completely closed.
But regarding your original issue...
Your bathroom circuit either has too small a heating surface area, too large spacing between the heating pipes in the floor, or the flow rate is too low.
Hello Mycraft, thank you for your post.
Where is the mistake in my approach? You think that this is a bad idea...
My question or problem is actually that I find it odd that water flows through even the closed heating circuits. As I mentioned: even when I had shut off all the heating circuits, the water still flowed through. I find that strange. So my question is whether this is normal.
In hindsight, I really should have laid the pipes closer together in the bathroom. There, I installed the pipes with a 15cm (6 inches) spacing, just like everywhere else. However, due to the structural conditions (installation wall, walk-in shower), the spacing effectively became wider. I thought the underfloor heating would fully compensate for this...
Where is the mistake in my approach? You think that this is a bad idea...
My question or problem is actually that I find it odd that water flows through even the closed heating circuits. As I mentioned: even when I had shut off all the heating circuits, the water still flowed through. I find that strange. So my question is whether this is normal.
In hindsight, I really should have laid the pipes closer together in the bathroom. There, I installed the pipes with a 15cm (6 inches) spacing, just like everywhere else. However, due to the structural conditions (installation wall, walk-in shower), the spacing effectively became wider. I thought the underfloor heating would fully compensate for this...
arner schrieb:
I installed the pipe there with a 15cm (6 inches) spacing, just like everywhere else. Due to the structural conditions (installation wall, walk-in shower), the spacing ended up being less overall. I thought the wall heating would fully compensate for that...That spacing is way too wide for a bathroom (unless it is sparingly heated)... unless the room is about 20 square meters (215 square feet) or larger... but as your experience shows, the pipes should have been laid closer together and the wall heating is not sufficient.
You basically have two options now: higher flow rate and/or higher supply temperature.
Your mistake is flushing with regular tap water. Heating systems, especially underfloor heating, require demineralized (VE) water and not just fresh tap water. That is most likely the cause of the cloudiness you are describing.
Hello,
@Mycraft: Deionized water (VE water) is not related to underfloor heating but is used for the heat exchangers in boilers. These heat exchangers are sensitive to hard water containing calcium. This issue doesn’t arise with heat pumps or older cast iron or wood-fired boilers. Nowadays, due to thorough research, the requirements for fill water are specified in VDI 2035-2. As a result, deionized water is used even in systems where it isn’t strictly necessary. However, it also has drawbacks. I spent weeks researching this and still am not entirely convinced, even though I have to use osmosis water myself because I have a condensing gas boiler with an aluminum heat exchanger. It’s important to test the water and monitor the pH level.
Things used to be simpler…
@Mycraft: Deionized water (VE water) is not related to underfloor heating but is used for the heat exchangers in boilers. These heat exchangers are sensitive to hard water containing calcium. This issue doesn’t arise with heat pumps or older cast iron or wood-fired boilers. Nowadays, due to thorough research, the requirements for fill water are specified in VDI 2035-2. As a result, deionized water is used even in systems where it isn’t strictly necessary. However, it also has drawbacks. I spent weeks researching this and still am not entirely convinced, even though I have to use osmosis water myself because I have a condensing gas boiler with an aluminum heat exchanger. It’s important to test the water and monitor the pH level.
Things used to be simpler…
Hello,
the heating circuits were also filled with water treated by a reverse osmosis system. However, our heating technician said that it would not be a big problem if one circuit was flushed with regular water, as the water volume in that circuit is relatively small compared to the total volume.
Best regards!
the heating circuits were also filled with water treated by a reverse osmosis system. However, our heating technician said that it would not be a big problem if one circuit was flushed with regular water, as the water volume in that circuit is relatively small compared to the total volume.
Best regards!
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