Method for micro-leakage detection in a fluid system, wherein the fluid system has a fluid pipe with a fluid valve, wherein a fluid flow through the fluid pipe is stopped when the fluid valve is closed, and wherein a fluid flow through the fluid pipe is allowed when the fluid valve is opened, the method comprising the following steps: measuring the fluid flow through the fluid pipe by a flow meter, measuring the pipe temperature of the fluid pipe by at least one pipe temperature sensor (17a, 17b), when there is no fluid flow measured by the flow meter, namely because or when the fluid flow through the fluid pipe is stopped by the fluid valve being closed, analyzing the pipe temperature for the micro-leakage detection, characterized by that the pipe temperature of the fluid pipe is measured by the at least one pipe temperature sensor (17a, 17b) when fluid flow is measured by the flow meter and when no fluid flow is measured by the flow meter, and the measured pipe temperature is analyzed for the micro-leakage detection only under the condition that there is no fluid flow measured by the flow meter, or the pipe temperature of the fluid pipe is both measured by the at least one pipe temperature sensor (17a, 17b) and analyzed for the micro-leakage detection only under the condition that there is no fluid flow measured by the flow meter. wherein the fluid system has a fluid pipe with a fluid valve, wherein a fluid flow through the fluid pipe is stopped when the fluid valve is closed, and wherein a fluid flow through the fluid pipe is allowed when the fluid valve is opened, measuring the fluid flow through the fluid pipe by a flow meter, measuring the pipe temperature of the fluid pipe by at least one pipe temperature sensor (17a, 17b), when there is no fluid flow measured by the flow meter, namely because or when the fluid flow through the fluid pipe is stopped by the fluid valve being closed, analyzing the pipe temperature for the micro-leakage detection, characterized by that the pipe temperature of the fluid pipe is measured by the at least one pipe temperature sensor (17a, 17b) when fluid flow is measured by the flow meter and when no fluid flow is measured by the flow meter, and the measured pipe temperature is analyzed for the micro-leakage detection only under the condition that there is no fluid flow measured by the flow meter, or the pipe temperature of the fluid pipe is both measured by the at least one pipe temperature sensor (17a, 17b) and analyzed for the micro-leakage detection only under the condition that there is no fluid flow measured by the flow meter. the pipe temperature of the fluid pipe is measured by the at least one pipe temperature sensor (17a, 17b) when fluid flow is measured by the flow meter and when no fluid flow is measured by the flow meter, and the measured pipe temperature is analyzed for the micro-leakage detection only under the condition that there is no fluid flow measured by the flow meter, or the pipe temperature of the fluid pipe is both measured by the at least one pipe temperature sensor (17a, 17b) and analyzed for the micro-leakage detection only under the condition that there is no fluid flow measured by the flow meter.