Table 5-2 lists possible remedies for a number of different operating problems associated with thermocouples.
Symptom and Possible Cause | Possible Remedy |
Pilot flame lit but safety control fails to function. | |
(a) Thermocouple not hot enough to generate current. | (a) Wait at least 1 minute for thermocouple to become hot enough. |
(b) Drafts deflecting flame away from thermocouple. | (b) Eliminate source of draft. |
(c) Pilot flame too small or yellow in color due to restricted pilot line or dirt in primary air opening or burner head. | (c) Disconnect, clean thoroughly, and reconnect. Change orifice if necessary. |
(d) Loose or dirty electrical connections. | (d) Disconnect, clean, reconnect, and tighten. |
(e) Thermocouple tip too low in pilot flame mounted in bracket. | (e) Check installation to make sure thermocouple is properly. |
Safety control operates but fails when main burner has been on a short time. | |
(a) Restriction in pilot or main gas tubing. | (a) Eliminate restriction. Provide normal pressure. |
(b) Draft-deflecting flame couple. | (b) Eliminate draft or baffle. |