I have a Bryant Plus 80V furnace (model # 315AAV0). I am having an issue with getting the fan go to high speed when using the Continous Fan mode. I have the dip switches set to have it run on the highest setting and it still only spins at the lowest speed. Also about every few days the 3 amp fuse on the control board blows!
Here is a brief discription of what I am doing. In the winter I use an outside wood "water" furnace to heat water and then run it through a radiator which is mounted just above the A coil in the furnace. I turn down the house thermostat (the one installed with the house furnace system) and use an additional t-stat for the water system. I then tied into the G and 24 V com terminal on the control board of the furnace. Using this system worked all last winter flawlessly and up until about one month ago. I was working on the outside wood furnace so I switched the t-stat to off while the water temp would be cool. Then in a few hours I turned it back on the blower fan was running only in low, and it has been this way ever since. If I run the furnace/heat pump the fan goes to high as designed?????? Any help would be great. Is it a control board?????? The fan running on low is not so bad, its when the fuse blows at night and it stops thats bad especially when its below 0 outside.
You were supposed to run a wire from the R terminal to G. You may have damaged the board. When wired properly it is programmed and designed to run on the lowest speed on some brands ie: Lennox when G is energized. Y energizes the cooling fan relay/high speed like G used to do.
"Cut it twice and it is still too short".