Heat source machine

A heat source machine which performs a heating operation of heating water to be heated by a heating unit, the heat source machine comprising:

• a comparison target input unit which inputs specifications of a reference heat source machine as a comparison target;
• a first emission amount calculation unit which calculates a first carbon dioxide emission amount, the first carbon dioxide emission amount being an amount of carbon dioxide emitted to obtain energy consumed in the case of performing the heating operation;
• a second emission amount calculation unit which calculates a second carbon dioxide emission amount, the second carbon dioxide emission amount being an assumed amount of carbon dioxide emitted to obtain energy consumed in the reference heat source machine on an assumption that the reference heat source machine performs the same operation as the heating operation;
• and
• a carbon dioxide emission reduction degree display unit which displays a carbon dioxide emission reduction degree that results from changing to the heat source machine, according to a difference between the first carbon dioxide emission amount and the second carbon dioxide emission amount.