Hello,
we are currently struggling with our heating system. It is warm everywhere in the house—both on the ground floor and in the heated basement room—around 21-22°C (70-72°F). However, the temperature in all rooms in the attic is noticeably lower, usually about 2°C (3.6°F) difference. This is problematic because a) it is too cold and b) it also affects the bathroom.
We have already tried various measures. We adjusted the heating curve, the manufacturer’s service performed a firmware update, and the hydraulic balancing was done again... but the problem remains the same. The attic stays consistently about 2°C (3.6°F) cooler than the other floors. The heating technician said this is normal because of the many windows and that it always tends to be cooler in the attic. He advised us to simply increase the supply water temperature. But that can’t be the solution, right? Although this raises the temperature in the attic, we then have to lower the temperature on the ground floor because otherwise it becomes too hot. The 2°C (3.6°F) difference always stays the same. We have solid ceilings and walls, underfloor heating everywhere, and the room thermostats turned up fully.
Is this really normal, or is the heating technician just trying to sell us that because he has no other ideas? What is your experience? Do you also have such temperature differences?
we are currently struggling with our heating system. It is warm everywhere in the house—both on the ground floor and in the heated basement room—around 21-22°C (70-72°F). However, the temperature in all rooms in the attic is noticeably lower, usually about 2°C (3.6°F) difference. This is problematic because a) it is too cold and b) it also affects the bathroom.
We have already tried various measures. We adjusted the heating curve, the manufacturer’s service performed a firmware update, and the hydraulic balancing was done again... but the problem remains the same. The attic stays consistently about 2°C (3.6°F) cooler than the other floors. The heating technician said this is normal because of the many windows and that it always tends to be cooler in the attic. He advised us to simply increase the supply water temperature. But that can’t be the solution, right? Although this raises the temperature in the attic, we then have to lower the temperature on the ground floor because otherwise it becomes too hot. The 2°C (3.6°F) difference always stays the same. We have solid ceilings and walls, underfloor heating everywhere, and the room thermostats turned up fully.
Is this really normal, or is the heating technician just trying to sell us that because he has no other ideas? What is your experience? Do you also have such temperature differences?
K
Knallkörper8 Mar 2017 20:25The following information suggests that your flow rate is too low:
- only 0.3 to 0.5 K (0.5 to 0.9°F) increase in room temperature when the supply temperature is raised by 5 K (9°F)
- generally rather high supply temperature
- areas where the coils are less tightly spaced become warmer
- pump set to level 1 only
- coils subjectively installed too close together
What is the temperature difference between supply and return? Have you already tried restricting all the circuits at the bottom?
- only 0.3 to 0.5 K (0.5 to 0.9°F) increase in room temperature when the supply temperature is raised by 5 K (9°F)
- generally rather high supply temperature
- areas where the coils are less tightly spaced become warmer
- pump set to level 1 only
- coils subjectively installed too close together
What is the temperature difference between supply and return? Have you already tried restricting all the circuits at the bottom?
Although it is already somewhat late in the year (the heating will soon be turned off again), so this effect is less pronounced, I am generally familiar with the phenomenon described here. The original installer checked/adjusted the valves twice (according to calculations) and has now given up on troubleshooting. Another installer has so far suggested as an initial diagnosis that a hydraulic separator is missing, which is supposed to decouple heat generation from heat distribution. This apparently costs around 2000 euros additionally...
Otherwise, I have also been advised as a solution to increase the heating curve, but somehow that doesn’t seem to be the right approach.
Good luck
K1300S
Otherwise, I have also been advised as a solution to increase the heating curve, but somehow that doesn’t seem to be the right approach.
Good luck
K1300S
Hello,
At -20°C (–4°F) outside, I actually find a flow temperature of 35°C (95°F) rather low, not high. For us, at -20°C (–4°F), it tends to be closer to 40°C (104°F) flow temperature.
What flow temperature do you have currently at outside temperatures between 0 and 10°C (32 and 50°F)? You would need to reduce it down to about 25°C (77°F) flow temperature by then, which starts to get quite challenging for heating. Or do you have a 5 cm (2 inch) pipe spacing??
Best regards,
Andreas
Nafetsm schrieb:
The flow temperature is set to a maximum of 35 degrees at an outside temperature of -20 degrees.
At -20°C (–4°F) outside, I actually find a flow temperature of 35°C (95°F) rather low, not high. For us, at -20°C (–4°F), it tends to be closer to 40°C (104°F) flow temperature.
What flow temperature do you have currently at outside temperatures between 0 and 10°C (32 and 50°F)? You would need to reduce it down to about 25°C (77°F) flow temperature by then, which starts to get quite challenging for heating. Or do you have a 5 cm (2 inch) pipe spacing??
Best regards,
Andreas
andimann schrieb:
At -20°C (−4°F) outside, I actually find a supply temperature of 35°C (95°F) rather low, not high. At -20°C (−4°F), we tend to go more towards 40°C (104°F) supply temperature.I have set a slope of 0.2 for our system.
Starting at 20°C (68°F), the supply temperature is 25°C (77°F), and at -20°C (−4°F) it should be around 33°C (91°F).
I found this worked better for me than the standard settings posted below.
+20°C (68°F) .. 25°C (77°F)
+15°C (59°F) .. 26°C (79°F)
+10°C (50°F) .. 27°C (81°F)
+5°C (41°F) ... 28°C (82°F)
+0°C (32°F) ... 29°C (84°F)
-5°C (23°F) ... 30°C (86°F)
-10°C (14°F) .. 31°C (88°F)
-15°C (5°F) ... 32°C (90°F)
-20°C (−4°F) .. 33°C (91°F)
The default setting was a slope of 0.3.
Starting at 20°C (68°F), the supply temperature is 25°C (77°F), and at -20°C (−4°F) it should be about 33°C (91°F).
+20°C (68°F) .. 23°C (73°F)
+15°C (59°F) .. 24.5°C (76°F)
+10°C (50°F) .. 26°C (79°F)
+5°C (41°F) ... 27.5°C (82°F)
+0°C (32°F) ... 29°C (84°F)
-5°C (23°F) ... 30.5°C (87°F)
-10°C (14°F) .. 32°C (90°F)
-15°C (5°F) ... 33.5°C (92°F)
-20°C (−4°F) .. 35°C (95°F)
Hello,
it’s time to give an update.
The heating technician visited again. He still refuses to flush the heating circuits. His claim is that the problem is definitely not due to that, otherwise there would be no flow in the circuits at all and the system wouldn’t warm up. What do you make of this statement?
He then used a thermal imaging camera to check each floor randomly. The interesting thing is that the floor temperature always shows between 24.4 and 25 degrees Celsius (75.9 and 77 degrees Fahrenheit). The room temperature on the ground floor and first floor is around 22.5 degrees Celsius (72.5 degrees Fahrenheit) (room thermostat set to level 3), but in the attic, despite the same floor temperature, the room temperature is only 21 degrees Celsius (69.8 degrees Fahrenheit) (thermostat set to level 6). That is absolutely illogical. Just as illogical is that increasing the flow temperature from 33 to 43 degrees Celsius (91 to 109 degrees Fahrenheit) raised the room temperature in the attic by only 0.2 degrees Celsius (0.4 degrees Fahrenheit).
If we turn all room thermostats up fully, we reach about 24.x degrees Celsius (75.x degrees Fahrenheit) in every room except the attic, where it remains at 21.
Today’s explanation was: it’s due to the high humidity… the higher the humidity, the lower the temperature… this sounds like nonsense to me…
He then adjusted the flow rates again, reducing flow on the ground and first floor, and increasing it in the attic by 0.5 liters (0.13 gallons). So far, after the first 18 hours, this has also had no effect… the flow rate in all attic heating circuits remains at 2 liters per minute (0.53 gallons per minute).
I am slowly running out of ideas. And they are resisting bleeding the system with all their might…
No idea what to do now. But this can’t be normal, can it?!
it’s time to give an update.
The heating technician visited again. He still refuses to flush the heating circuits. His claim is that the problem is definitely not due to that, otherwise there would be no flow in the circuits at all and the system wouldn’t warm up. What do you make of this statement?
He then used a thermal imaging camera to check each floor randomly. The interesting thing is that the floor temperature always shows between 24.4 and 25 degrees Celsius (75.9 and 77 degrees Fahrenheit). The room temperature on the ground floor and first floor is around 22.5 degrees Celsius (72.5 degrees Fahrenheit) (room thermostat set to level 3), but in the attic, despite the same floor temperature, the room temperature is only 21 degrees Celsius (69.8 degrees Fahrenheit) (thermostat set to level 6). That is absolutely illogical. Just as illogical is that increasing the flow temperature from 33 to 43 degrees Celsius (91 to 109 degrees Fahrenheit) raised the room temperature in the attic by only 0.2 degrees Celsius (0.4 degrees Fahrenheit).
If we turn all room thermostats up fully, we reach about 24.x degrees Celsius (75.x degrees Fahrenheit) in every room except the attic, where it remains at 21.
Today’s explanation was: it’s due to the high humidity… the higher the humidity, the lower the temperature… this sounds like nonsense to me…
He then adjusted the flow rates again, reducing flow on the ground and first floor, and increasing it in the attic by 0.5 liters (0.13 gallons). So far, after the first 18 hours, this has also had no effect… the flow rate in all attic heating circuits remains at 2 liters per minute (0.53 gallons per minute).
I am slowly running out of ideas. And they are resisting bleeding the system with all their might…
No idea what to do now. But this can’t be normal, can it?!
Nafetsm schrieb:
The room temperature on the ground floor and first floor is about 22.5°C (72.5°F) each (room thermostat set to level 3), but on the attic floor, despite the same floor temperature, the room temperature is only 21°C (70°F) (set to level 6). This makes absolutely no sense.The opposite is true; this is completely logical... you have higher heat losses in the attic compared to the ground floor because there is a roof above where heat can escape...
But this has already been explained to you several times here.
Similar topics