working on a inter city products gas furnace
867.766132 ( i think this is what it is as it was hard to see )
ok we put a new thermocouple on it ( we didnt have or could get the right one at the time so we made one fit) and it worked good for 3 months or so then wouldn't kick on so we got the right one for this model still didnt work we then found a rollout switch had tripped reset that and it work good for a few hours we check it again found the same rollout switch tripped so we put a new rollout switch on it worked good for a few hours then would not kick on so we put a new thermostat on and set it for 68 F well then it worked just fine for 2 or 3 days then same thing will not kick on and the roll out switch tripped so the guy at the house tells me that when they set the hest up to about 70 or 70 F is when it stopped working ... so now we are thinking that the fan limit switch maybe the problem ???? so times the fan will run but no heat on ( customer said it just blows cold air some times ) we also check both rollout switchs and the vent switch all test ok
it seems that when they turn up the heat is when it tripps the rollout switch the guy said he turned it down when he went to bed last night and today when they got up he turned it up and and after it kicked off it wound't kick back on
anyone have any idea ??