It is possible that this noise is caused by the Eteck heating installation or by components in the indoor system. You can check this by closing all valves on the heating unit, in the opposite direction of the pipe. If the noise does not stop, please contact your indoor installation contractor or landlord.If the noise does stop, the heating unit will likely be the problem. In this case, please contact Eteck via MijnEteck (Dutch), by phone 085-0218000 or contact us digitally.