| 摘要 |
PURPOSE:To detect failure of heating source control relay without increase in the number of parts by comparing a temperature detection signal during OFF control of the heating source control relay with a preset irregular temperature signal using a temperature detection sensor to detect failure of the heating source control relay with a relay failure detecting means. CONSTITUTION:On the occasion of controlling ON/OFF conditions of the heating source 101 depending on the temperature detection signal from a temperature detection sensor 104, a failure of the heating source control relay 105b is detected with a relay failure detecting means 105c by comparing the temperature detecting signal during OFF control of the heating source control relay 105b with the preset failure temperature signal. Thereby, failure of the heating source control relay 105b can be detected without increase in the number of parts by utilizing the temperature detection sensor 104 on the occasion of ON/OFF control of the heating source 101. |
