Hello everyone,
Our heating system consumed about 8,700 kWh of natural gas between 12/16 and 06/17, even though the house is still being renovated and unoccupied. All radiators were set to frost protection only, and no domestic hot water was used.
The system was installed in 12/15 by the previous owners and mainly consists of:
This summer, I noticed that the pipe from the solar collector (supply line) was only hot up to the pump, while the return line was almost cold. From this, I concluded that the pump was not running. At the same time, the controller showed 999°C (1,830°F) for the temperature sensor mounted at the top of the collector, which the technician said is the maximum display value indicating no plausible reading.
Testing the temperature sensor (a PT1000) was successful, so the technician concluded that the controller itself must be defective (he believed the pump was still operational).
So, a new controller was ordered, which I am still waiting for as of today, but that’s another story...
Now, with the cold season approaching, we have temporarily installed some radiators to heat the construction site a little and, most importantly, to ensure frost protection.
I was able to reduce the natural gas consumption by lowering the target temperature for domestic hot water to 10°C (50°F); however, I would say the consumption is still quite high (since Saturday, so in 4 days, about 30 m³ [1,059 ft³]... :O).
Is it possible that due to the defective controller, the 800-liter (210-gallon) water volume of the solar thermal system is being kept warm using natural gas, and usually the ESR 31, depending on whether heat is available from the roof or not, activates or deactivates a heat exchanger between the domestic hot water tank and the solar thermal water system, which in our case might currently always be open or something like that?
Maybe someone, even as a layperson, can explain how a combined stratified storage tank works or is constructed?
Many thanks in advance!
Best regards
PS: The heating technician is hard to reach; unfortunately, I have to work with him since this is obviously a warranty case. Once this issue is resolved, he definitely won’t touch our heating system again… -.-
Our heating system consumed about 8,700 kWh of natural gas between 12/16 and 06/17, even though the house is still being renovated and unoccupied. All radiators were set to frost protection only, and no domestic hot water was used.
The system was installed in 12/15 by the previous owners and mainly consists of:
- Viessmann Vitodens 200 gas condensing wall unit 19 kW
- Austria Email KWS 800 combined stratified storage tank
- Flat plate solar collectors 9.36 m² (100.8 ft²)
- ESR 31 solar controller
- Delphis solar station FV 70 (with Grundfos circulation pump on the supply side)
This summer, I noticed that the pipe from the solar collector (supply line) was only hot up to the pump, while the return line was almost cold. From this, I concluded that the pump was not running. At the same time, the controller showed 999°C (1,830°F) for the temperature sensor mounted at the top of the collector, which the technician said is the maximum display value indicating no plausible reading.
Testing the temperature sensor (a PT1000) was successful, so the technician concluded that the controller itself must be defective (he believed the pump was still operational).
So, a new controller was ordered, which I am still waiting for as of today, but that’s another story...
Now, with the cold season approaching, we have temporarily installed some radiators to heat the construction site a little and, most importantly, to ensure frost protection.
I was able to reduce the natural gas consumption by lowering the target temperature for domestic hot water to 10°C (50°F); however, I would say the consumption is still quite high (since Saturday, so in 4 days, about 30 m³ [1,059 ft³]... :O).
Is it possible that due to the defective controller, the 800-liter (210-gallon) water volume of the solar thermal system is being kept warm using natural gas, and usually the ESR 31, depending on whether heat is available from the roof or not, activates or deactivates a heat exchanger between the domestic hot water tank and the solar thermal water system, which in our case might currently always be open or something like that?
Maybe someone, even as a layperson, can explain how a combined stratified storage tank works or is constructed?
Many thanks in advance!
Best regards
PS: The heating technician is hard to reach; unfortunately, I have to work with him since this is obviously a warranty case. Once this issue is resolved, he definitely won’t touch our heating system again… -.-
Too good to be true...
About seven weeks ago, we rerouted the pipes (they no longer run up to the ridge but go through the attic to the collectors), so now the collectors are the highest point. The heating technician then connected the pipes (the supply line had to be extended by about 2 meters (6.5 feet)), refilled the system, and flushed it—afterwards, everything worked perfectly in my opinion until about a week ago!
On Sunday, just before noon (since then I have been regularly checking the control system values several times a day whenever possible), I noticed the temperature at the roof was over 130°C (266°F), and accordingly the pump was off. Immediately I suspected the problem was starting again because I assume that if the circulation is working properly, the temperature on the roof wouldn’t reach such a high level so quickly or at all. (There were days that were much sunnier and longer lasting, and I never saw more than 85°C (185°F) on the roof, while the temperature in the stratified storage tank was raised to over 51°C (124°F), and it holds 800 liters (210 gallons) of volume!)
A few days later I still saw over 70°C (158°F) at the supply line at the bottom, but both the return line and the temperature in the tank barely increased. Since yesterday, nothing is working again—both supply and return lines remain steady at about 20°C (68°F), even though the temperature at the roof is high and the pump is being controlled and running until the upper threshold is exceeded and it shuts off again...
The system must be sealed because the pressure remains at about 2.5 bar (36 psi) or sometimes rises above 4 bar (58 psi) when the temperature at the collector increases (sometimes over 150°C (302°F)).
What I find odd: on my collectors (four units), both supply and return lines are connected at the top! (That is, the supply is connected at the top of the right module and the return at the top of the left module!) All other collectors I have seen in this area have the supply and return connected at the same module, top and bottom! However, my heating technician said there are also collectors where both lines are connected at the top...
By the way, my system has heating support, as it turned out—does this still play a role?
The last option I can think of as a layperson would be to install an air separator directly at the top of the collector, at the highest point, right?
One more question about the stratified storage tank: Is there a disadvantage to having a tank this large, in that if, for example, there is no sun in winter or the system isn’t working like in my case, significantly more gas is consumed because much more domestic hot water needs to be heated? It certainly seems to me like the heating needs to run constantly (when the solar thermal system was working properly, we sometimes didn’t use any gas at all according to the gas meter!).
Many thanks in advance for your time and effort!
Best regards
About seven weeks ago, we rerouted the pipes (they no longer run up to the ridge but go through the attic to the collectors), so now the collectors are the highest point. The heating technician then connected the pipes (the supply line had to be extended by about 2 meters (6.5 feet)), refilled the system, and flushed it—afterwards, everything worked perfectly in my opinion until about a week ago!
On Sunday, just before noon (since then I have been regularly checking the control system values several times a day whenever possible), I noticed the temperature at the roof was over 130°C (266°F), and accordingly the pump was off. Immediately I suspected the problem was starting again because I assume that if the circulation is working properly, the temperature on the roof wouldn’t reach such a high level so quickly or at all. (There were days that were much sunnier and longer lasting, and I never saw more than 85°C (185°F) on the roof, while the temperature in the stratified storage tank was raised to over 51°C (124°F), and it holds 800 liters (210 gallons) of volume!)
A few days later I still saw over 70°C (158°F) at the supply line at the bottom, but both the return line and the temperature in the tank barely increased. Since yesterday, nothing is working again—both supply and return lines remain steady at about 20°C (68°F), even though the temperature at the roof is high and the pump is being controlled and running until the upper threshold is exceeded and it shuts off again...
The system must be sealed because the pressure remains at about 2.5 bar (36 psi) or sometimes rises above 4 bar (58 psi) when the temperature at the collector increases (sometimes over 150°C (302°F)).
What I find odd: on my collectors (four units), both supply and return lines are connected at the top! (That is, the supply is connected at the top of the right module and the return at the top of the left module!) All other collectors I have seen in this area have the supply and return connected at the same module, top and bottom! However, my heating technician said there are also collectors where both lines are connected at the top...
By the way, my system has heating support, as it turned out—does this still play a role?
The last option I can think of as a layperson would be to install an air separator directly at the top of the collector, at the highest point, right?
One more question about the stratified storage tank: Is there a disadvantage to having a tank this large, in that if, for example, there is no sun in winter or the system isn’t working like in my case, significantly more gas is consumed because much more domestic hot water needs to be heated? It certainly seems to me like the heating needs to run constantly (when the solar thermal system was working properly, we sometimes didn’t use any gas at all according to the gas meter!).
Many thanks in advance for your time and effort!
Best regards
Hello,
have you checked if the air separator has been bled recently?
It also collects oxygen released from the liquid after the system starts operating.
An additional venting option only works if it is actually used.
Which type of collector is installed? You might want to compare the installation instructions with the actual setup.
Please upload some pictures showing the route of the solar pipes
a) from the buffer tank to the pump station, and
b) from the pump station to the shaft.
Olli
have you checked if the air separator has been bled recently?
It also collects oxygen released from the liquid after the system starts operating.
An additional venting option only works if it is actually used.
Which type of collector is installed? You might want to compare the installation instructions with the actual setup.
Please upload some pictures showing the route of the solar pipes
a) from the buffer tank to the pump station, and
b) from the pump station to the shaft.
Olli
First of all, thank you for your time and efforts!
Good idea, something did seem unusual, my heating engineer also mentioned that: Unfortunately, I don’t remember exactly, but some valve or similar is installed on the supply line with me and “normally” on the return line or vice versa. However, the function is supposedly given.
What I can say for sure is that since Sunday it hasn’t worked either when heating the house or when only heating the domestic hot water. (The supply and return lines are always only 20°C (68°F) even though the pump is running and there is sufficient heat on the roof!)
I have. Quite a bit of air came out, but that didn’t improve anything. Now, when I bleed it, fluid immediately comes out.
I believe they are Delphis; I will check more precisely which type on the invoices. I will definitely contact Delphis to verify whether the connection of the supply and return lines at the top is correct!
I will take appropriate pictures on Wednesday and upload them here! One more question: What do you mean by shaft? The lines run through an unused flue of a chimney to the roof. Is that what you mean?
Thanks again!
Best regards
Lumpi_LE schrieb:
Since you mentioned "with heating support," could it be a 3-way valve that isn’t switching? Meaning it works as long as the house is being heated, but stops working when only domestic hot water is being heated.
Good idea, something did seem unusual, my heating engineer also mentioned that: Unfortunately, I don’t remember exactly, but some valve or similar is installed on the supply line with me and “normally” on the return line or vice versa. However, the function is supposedly given.
What I can say for sure is that since Sunday it hasn’t worked either when heating the house or when only heating the domestic hot water. (The supply and return lines are always only 20°C (68°F) even though the pump is running and there is sufficient heat on the roof!)
wrobel schrieb:
Have you also bled the air separator in the meantime?
I have. Quite a bit of air came out, but that didn’t improve anything. Now, when I bleed it, fluid immediately comes out.
What type of collector is installed? You could compare the installation manual with the actual installation.
I believe they are Delphis; I will check more precisely which type on the invoices. I will definitely contact Delphis to verify whether the connection of the supply and return lines at the top is correct!
Please post some pictures showing the routing of the solar lines:
a) from the buffer tank to the pump station and
b) from the pump station to the shaft.
I will take appropriate pictures on Wednesday and upload them here! One more question: What do you mean by shaft? The lines run through an unused flue of a chimney to the roof. Is that what you mean?
Thanks again!
Best regards
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