ᐅ Upgrading House Connection and Construction Cost Subsidy from 30 kW to 40 kW – Any Experiences?
Created on: 3 Jul 2025 20:18
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hugi-01Hello,
Our Vaillant VWL 55/6 heat pump has been running since October 24, and the heating technician / electrician still hasn’t fully completed the registration process.
Now we received an email from the utility company EWE-Netz:
“To ensure everything runs smoothly from the start, we checked whether the capacity of your device matches your house connection and our grid. The answer is ‘No, unfortunately not.’ The individual components are not yet sufficiently sized. Your connection and our grid first require an upgrade.”
Today, we received an offer for the upgrade of our house connection:
“Construction cost contribution for power increase from 30kW to 40kW”
Total including VAT 370€.
Is this common, and is it justified? Our house was built in 1997,
the main breaker in the fuse box is rated 63A, and on the transition box below the fuse box it says 1x3 NH 00 500V.
The house is equipped normally, but we also have a wallbox that could theoretically draw 11.1 kW.
Good luck
Our Vaillant VWL 55/6 heat pump has been running since October 24, and the heating technician / electrician still hasn’t fully completed the registration process.
Now we received an email from the utility company EWE-Netz:
“To ensure everything runs smoothly from the start, we checked whether the capacity of your device matches your house connection and our grid. The answer is ‘No, unfortunately not.’ The individual components are not yet sufficiently sized. Your connection and our grid first require an upgrade.”
Today, we received an offer for the upgrade of our house connection:
“Construction cost contribution for power increase from 30kW to 40kW”
Total including VAT 370€.
Is this common, and is it justified? Our house was built in 1997,
the main breaker in the fuse box is rated 63A, and on the transition box below the fuse box it says 1x3 NH 00 500V.
The house is equipped normally, but we also have a wallbox that could theoretically draw 11.1 kW.
Good luck
W
wiltshire3 Jul 2025 22:00EWE can decide on the connection capacity, and you have no influence over that. I have seen prices for this kind of work that were even higher. Just have it done and don’t worry about it further. It’s pointless.
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RotorMotor4 Jul 2025 07:14Are devices up to 11 kW only subject to notification requirements?
How does the utility company then come to "refuse" them?
And besides, you already have a 44 kW connection.
What do they want to change with the 370€?
How does the utility company then come to "refuse" them?
And besides, you already have a 44 kW connection.
What do they want to change with the 370€?
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wiltshire4 Jul 2025 08:33RotorMotor schrieb:
What do they want to change for the €370? The fact that the main switch in the distribution board is rated at 63A does not indicate how the network connection is actually sized. This is determined by the SLS (selective circuit breaker). The SLS belongs to the utility provider, essentially to the meter, and not yet to the house. Therefore, I assume that EWE knows what equipment they have installed.
RotorMotor schrieb:
What do they want to change for the €370? In any case, the SLS will be replaced.
If the supply cable has only a 10mm² (10.8 sq. ft.) cross-section instead of the 16mm² (17.2 sq. ft.) required for 40kW, it must also be replaced.
The network inspection includes the sizing within the low-voltage network to cover any necessary work there.
The price does not seem too high to me.
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MachsSelbst4 Jul 2025 08:35Don’t worry, RotorMotor, you’ll learn this in your second year of training.
Because what the main switch "has" or what’s written on the fuse box about the fuse type doesn’t tell you anything about the fuses currently installed in the house connection.
Most likely, it’s currently 3x40A NH00 fuses, which means about 27kW. The utility provider probably wants to upgrade that to 3x63A, which would be just under 44kW. And that costs money because someone has to come out, replace the fuses, seal it again, handle the paperwork, and so on.
370 EUR is likely at the high end, but that’s just how it is.
PS:
A house connection never has 10 or 16 mm² (square millimeters). The usual cables are NYY 5x35 mm² (5x0.054 in²), or sometimes 5x25 mm² (5x0.039 in²) for cost-saving reasons.
Because what the main switch "has" or what’s written on the fuse box about the fuse type doesn’t tell you anything about the fuses currently installed in the house connection.
Most likely, it’s currently 3x40A NH00 fuses, which means about 27kW. The utility provider probably wants to upgrade that to 3x63A, which would be just under 44kW. And that costs money because someone has to come out, replace the fuses, seal it again, handle the paperwork, and so on.
370 EUR is likely at the high end, but that’s just how it is.
PS:
A house connection never has 10 or 16 mm² (square millimeters). The usual cables are NYY 5x35 mm² (5x0.054 in²), or sometimes 5x25 mm² (5x0.039 in²) for cost-saving reasons.
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RotorMotor4 Jul 2025 13:44wiltshire schrieb:
The fact that the main switch in the fuse box is rated at 63A doesn’t really say much ...
In any case, check the RCD first. I would just bet that @hugi-01 is using the terms interchangeably.
But yes, they should clarify which NH fuses are installed.
Although they probably can’t see that because it’s sealed.
If I’m correct in assuming the terms are used synonymously and a 63A RCD is installed, then the NH fuses ahead of it are also rated at 63A or higher.
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