Furnace starts out great & then later not?
Two trips in a row now are furnace starts out great! Lots of heat & by morning when we wake it blowing cold. Can anyone help me fix this? Suppose to another cold night.
Forum Discussion
Blanco, the translation is;
First, the furnace has a sensor which turns off the heat, but leaves the blower going, if the furnace gets too hot.
Secondly, they're asking if the burner keeps trying to start when the blower is running. The difference is there's a micro swith in the furnace called the "sail switch". Basically it's got a little tab connected to the switch, the tab sticks out into the airflow of the blower. If there's enough air flow (which pushes the switch shut) to safely allow the burner to run, it does. If not the burner will never light. If your batteries are low the blower motor turns too slowly and doesn't make enough airflow to close the switch.
The simplest, read very low-tech, test is when it's the coldest light every burner you have, put them on highest setting and see if a) they even light, b) get to full output, c) stay lit and at full output. NB: you may need to crack a window and / or put on the exhaust fan.
If you get less than perfect results from the above you'll know straight away it's a gas problem.
First, the furnace has a sensor which turns off the heat, but leaves the blower going, if the furnace gets too hot.
Secondly, they're asking if the burner keeps trying to start when the blower is running. The difference is there's a micro swith in the furnace called the "sail switch". Basically it's got a little tab connected to the switch, the tab sticks out into the airflow of the blower. If there's enough air flow (which pushes the switch shut) to safely allow the burner to run, it does. If not the burner will never light. If your batteries are low the blower motor turns too slowly and doesn't make enough airflow to close the switch.
The simplest, read very low-tech, test is when it's the coldest light every burner you have, put them on highest setting and see if a) they even light, b) get to full output, c) stay lit and at full output. NB: you may need to crack a window and / or put on the exhaust fan.
If you get less than perfect results from the above you'll know straight away it's a gas problem.
