PV system not working properly? We’ll find the fault and make sure it gets fixed.
From inverter faults and missing monitoring data to problems with your grid operator: we track down the fault on existing PV systems – including those installed by other companies – and make sure they run again. We plan new PV systems, battery storage and backup power for homes, businesses and farms to match your consumption.
Based in the Allgäu, working across Upper Bavaria. Larger projects throughout Germany by arrangement.
Is your system producing too little power, showing an error or missing from the monitoring portal? We find the cause – whether the problem is the inverter, data logger, cabling, network or settings – and make sure it gets fixed. Including systems installed by other companies.
Received a letter from your grid operator about remote control, telecontrol or new requirements? We check the equipment and connections, fix communication faults and coordinate directly with your grid operator.
We plan new PV systems for homes, businesses and farms, plus battery storage, emergency and backup power, off-grid systems and extensions. And we help when the 20-year EEG feed-in tariff ends. We develop our battery storage systems in-house, for new and existing installations.
Technik-Service Rethwisch is two electricians from the Allgäu who have worked together since vocational school. When you call, you speak to the people who assess the problem and work on your system. No call centre, no changing contacts.
Felix Rethwisch
Managing Director · Electronics technician for energy and building systems Focus on battery storage and backup power
Languages: GermanEnglish
Michael Komraus
Project Manager · Business Development Focus on renewable energy
Office dog · moral support Focus on toolboxes and quality control
Since 2021IHK member
Member of the Chamber of Industry and Commerce for Munich and Upper Bavaria.
Direct contactNo call centre
The person who advises you also works on your system – and stays reachable on the same number.
In-house developmentStorage & control
We develop battery storage and heating controls ourselves. That’s why we know them inside out.
DocumentedService report
You receive a written record of what we found and did – for you, the grid operator or your insurer.
How it works
How a service call works
01
Tell us what’s happening
By form, phone or WhatsApp: where is the system, and what is happening? Photos of error messages, type plates or grid operator letters are helpful.
02
We assess the problem
We respond within 48 hours on working days, review the information and discuss the next steps. If needed, we arrange an on-site visit.
03
We find the cause and agree the work
We test the system and fix faults in the data connection and settings on site where possible. For larger jobs, you receive a quote beforehand. At the end, you get a written record of the work.
Do you also look after PV systems installed by another company?
Yes. Servicing systems installed by other companies is a major part of our work. If available, send us the system documents, the inverter model and the latest error message.
My monitoring portal is offline. Does that mean the PV system has stopped generating?
Not necessarily. The fault is often in the internet connection, the data logger or the monitoring equipment. We check whether the system is generating power and find out why the data is missing.
Can you help with a letter from my grid operator?
Yes. Send us a copy of the letter. We review the requirements, check the equipment and coordinate the technical response with the grid operator.
Can battery storage or backup power be added to an existing PV system?
Often, yes. We first check the existing inverter, the electrical installation and your power requirements and plan a suitable solution.
Where do you work?
Our business is based in Igling. We regularly work in the Allgäu and across Upper Bavaria. We take on larger projects throughout Germany – and elsewhere in Europe by arrangement.
Contact
Report a fault or discuss your project
Tell us what’s happening or what you’re planning. We’ll get back to you within 48 hours on working days.
Contact form
Your enquiry has been received.
We’ll get back to you within 48 hours on working days. Urgent? Call us: +49 151 19600684