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… -.-
So, the pump is finally running!
When I took a closer look at the pump’s connection box, I noticed that the plastic on a component of the circuit board was chipped. This led me to suspect that the electronics were not working properly, which explained why the pump wasn’t running.
Unfortunately, Grundfos does not offer service to end customers, and I couldn’t find the connection box sold separately, so I ended up buying an entirely new pump. Now, I simply connected the new connection box to the existing pump, and voilà, the pump is running! (It’s audible and can be felt, and the temperature at the solar collector dropped significantly and quickly, which suggests the circulation is working.)
The control is working now, too; if the ESR doesn’t send a signal, the pump doesn’t run anymore!
What I find strange, however, is that the float inside the flow meter installed below the pump still doesn’t move. Could it be installed the wrong way around? As wrobel correctly pointed out, the pump has to be installed on the return line. What confuses me is that the pipe above the pump (the return line coming from the roof) feels noticeably warm, while the supply line at the Delphis solar station is not warm to the touch at all. So it’s possible that either the pump is mistakenly installed on the supply line and was perhaps damaged by the overly warm water, or the pump is installed backwards and is pumping the warm water from the roof toward the storage tank instead of the cold water upward from below? (Which would correspond to how a supply line functions, wouldn’t it?)
The installer was supposedly an expert in the field… -.-
Judging by the previous owners, it seems the priority was to keep costs as low as possible. I wouldn’t be surprised if the system never worked properly and no one noticed because the house was rented out before being sold…
Thanks in advance!
Best regards
When I took a closer look at the pump’s connection box, I noticed that the plastic on a component of the circuit board was chipped. This led me to suspect that the electronics were not working properly, which explained why the pump wasn’t running.
Unfortunately, Grundfos does not offer service to end customers, and I couldn’t find the connection box sold separately, so I ended up buying an entirely new pump. Now, I simply connected the new connection box to the existing pump, and voilà, the pump is running! (It’s audible and can be felt, and the temperature at the solar collector dropped significantly and quickly, which suggests the circulation is working.)
The control is working now, too; if the ESR doesn’t send a signal, the pump doesn’t run anymore!
What I find strange, however, is that the float inside the flow meter installed below the pump still doesn’t move. Could it be installed the wrong way around? As wrobel correctly pointed out, the pump has to be installed on the return line. What confuses me is that the pipe above the pump (the return line coming from the roof) feels noticeably warm, while the supply line at the Delphis solar station is not warm to the touch at all. So it’s possible that either the pump is mistakenly installed on the supply line and was perhaps damaged by the overly warm water, or the pump is installed backwards and is pumping the warm water from the roof toward the storage tank instead of the cold water upward from below? (Which would correspond to how a supply line functions, wouldn’t it?)
The installer was supposedly an expert in the field… -.-
Judging by the previous owners, it seems the priority was to keep costs as low as possible. I wouldn’t be surprised if the system never worked properly and no one noticed because the house was rented out before being sold…
Thanks in advance!
Best regards
First of all, thank you for taking the time to read my post and respond!
Attached are a few pictures from this afternoon. Unfortunately, there wasn’t enough sunlight left to raise the temperature on the roof significantly (picture 2, T1 is the sensor on the roof and, of course, the pump is currently not running).
I can, of course, take other or additional pictures if needed!
Could air in the system cause such a problem? I have already bled the air at the solar station (on the supply line); some air came out, but the float still doesn’t move even though the pump is running. Also, the pipes are barely warming up...
Logically, I should probably bleed at the top, at the collector, right?
Could the pump be installed the wrong way around? Then the float in the flow meter would be pushed down and wouldn’t float up at all, correct?
Thanks again in advance!
Regards
Attached are a few pictures from this afternoon. Unfortunately, there wasn’t enough sunlight left to raise the temperature on the roof significantly (picture 2, T1 is the sensor on the roof and, of course, the pump is currently not running).
I can, of course, take other or additional pictures if needed!
Could air in the system cause such a problem? I have already bled the air at the solar station (on the supply line); some air came out, but the float still doesn’t move even though the pump is running. Also, the pipes are barely warming up...
Logically, I should probably bleed at the top, at the collector, right?
Could the pump be installed the wrong way around? Then the float in the flow meter would be pushed down and wouldn’t float up at all, correct?
Thanks again in advance!
Regards
Hello
The pump appears to be installed correctly.
There is an arrow molded on the side of the pump housing; you can double-check that.
If there is truly no flow, flush and vent the system. If there is a significant amount of air in the solar circuit, this is the only way to remove it.
Olli
The pump appears to be installed correctly.
There is an arrow molded on the side of the pump housing; you can double-check that.
If there is truly no flow, flush and vent the system. If there is a significant amount of air in the solar circuit, this is the only way to remove it.
Olli
If there is air in the system, you will hear it when the system is running.
Solar thermal systems are not vented like radiators. This is done using an external pump.
The flow meter can sometimes stick at low flow rates; in winter, with the sun low on the horizon, it definitely won’t show much movement.
Solar thermal systems are not vented like radiators. This is done using an external pump.
The flow meter can sometimes stick at low flow rates; in winter, with the sun low on the horizon, it definitely won’t show much movement.
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