What size is the required connection for a thermometer on a hot water heating boiler?

The required size for a connection for a thermometer on a hot water heating boiler is 1/2 inch. This size is standard for ensuring adequate flow and accurate temperature readings while maintaining a balance between the size of the instrument and the connection point on the boiler. A 1/2 inch connection allows for the use of typical thermometers designed for this purpose, ensuring they're able to provide precise measurements without compromising the system's integrity or causing pressure issues.

Using a connection that is too small could result in restricted flow and inaccurate readings, while a larger connection would be unnecessary and could complicate installation. Therefore, the 1/2 inch size strikes the right balance for efficiency and functionality in the context of a hot water heating boiler system.