There are two valves in the heating pipe outside my building, and one valve at home can control it. What happened?

The two valves on the heating pipeline in the corridor are the main backwater valve and the main water inlet valve, which mainly control the water inlet and outlet of the heating in the corridor. And you have a valve in your home, which may be used to control the heating equipment in your own home, such as radiator or floor heating.

Usually the heating pipes in the corridor are interconnected, so if other users in the corridor don't close the valve correctly, it may affect your heating equipment. So you need to contact the property or heating company and ask them to help close the corresponding valves in the corridor so as to check and maintain your heating equipment.

It should be noted that the specific operation methods and steps may be slightly different, because the heating system and facilities in each community are different. It is recommended that you know the relevant regulations and operation methods first, so as to avoid unnecessary troubles and losses.