7. Oil-fired  Water  Heaters  1 When, in a testing laboratory that meets the temperature  conditions specified in JIS S3031 (2009) General Rules for Test  Methods of Oil Burning Appliances (hereinafter referred to as  the "General Rules for JIS Tests") 6.1.1 (such laboratory is  hereinafter referred to as a "JIS Laboratory"), measurement is  taken by the method for measuring the ratio of carbon monoxide  to carbon dioxide (CO/CO2) in the combustion exhaust gas as  specified in the General Rules for JIS Tests 6.7 (hereinafter  referred to as the "CO/CO2 Measuring Method for Oil-fired  Water Heaters"), the measurement value is no more than 0.01.  2 When a temperature rise test is conducted for each part as  specified in the General Rules for JIS Tests 6.1 and 6.2 e), f),  and i) in a JIS Laboratory, the results meet the following  conditions.  (1) The difference between the room temperature and the  surface temperature of the wooden stand below and around the  heater is no more than 65 degrees.  (2) The difference between the room temperature and the  surface temperature of the wooden walls above, at the sides  (including at the back), and in front of the heater is no more  than 65 degrees.  (3) Where the oil tank is combined with the heater body, the  difference between the room temperature and the surface  temperature of the oil tank is no more than 25 degrees.  (4) The difference between the room temperature and the oil  temperature is no more than 25 degrees.  (3) When a hot-water supply temperature test as specified in the  General Rules for JIS Tests 17. is conducted in a JIS  Laboratory, the hot-water supply temperature is no more than  90 degrees Celsius. In addition, the temperature of the water  circulating from the bathtub to the bath heater is no more than  60 degrees Celsius. Also, in the case of a heater having an  overtemperature protection device, when an activation test of  the overtemperature protection device as specified in the  General Rules for JIS Tests 15.2 is conducted on a directly- heated heat exchanger, the device extinguishes the fire before  the temperature reaches 100 degrees Celsius, and is not  restored automatically.  4 As functions for protecting the directly-heated heat exchanger,  the conditions listed in (1) and (2) below are met; provided,  however, that this does not apply in the case of a directly-heated  heat exchanger for a bath heater.  (1) Ignition is not possible when there is no water in the heat  exchanger.  (2) Fire is extinguished within three minutes after ignition  when there is no water in the heat exchanger.  37 