The water may, at any time, be shut off from the mains without notice for repairs or other necessary purposes, and the City will not be responsible for any consequent damages. Water for steam boilers should not be drawn by direct pressure from the mains, but owners of boilers should always provide tanks holding an ample reserve of water for such purposes. On all services on which there are hot water tanks, boilers or heating plants proper precaution should be taken against damage or collapse of such equipment in case water is shut off at the main or at the service pipe.