Fan Limit Switch is configurable.
Steps to change a specific limit:
1) disconnect power;
2) remove the switch cover
3) while holding down the dial panel with one hand, move the limit notch to the wanted temperature limit.
Pictures below:
1. Fan Limit Switch 外觀
2. 修改前設置
3. 修改後設置
Tenants mentioned it has been working like that since they moved in a few years ago.
They mentioned the furnace behavior and wanted it to be checked due to another unrelated reason.
The filter was replaced 4 weeks ago.
Some where on the internet, I saw the range can be set within 100F - 150F.
In addition, I noticed during heating process, the inside furnace temperature is always slightly above 150F.
How often the furnace burner and air duct should be cleaned?
