vicious circle with my furnace

[acproblem]

Here is a situation with my AC unit (fan outside the house). The average temp outside is 30 degrees. I keep temp inside the house at 74 degrees constant. I do not have any pre-programmed time schedule when temp should go up or down .. If I leave the house the temp drops top 61 and then the system turn on .. when I come back from work ..I set the time on 74 (hold on 74) and hold it for 14hrs …it takes couple of hrs to get from 61 to 74

The problem is that the fan outside the house seems to be working all the time ..it stops very rarely and sometimes there are some weird loud sounds (lasting no longer than 5 seconds) coming out of it ..
I observed that the furnace heats up the air and ..when the furnace stops working the fan keeps on going on pushes cold air from outside the house for some time..it does not get cold or anything but I think the …the temp drops and furnace goes back on …

Can you pls let me know whether there is something wrong with the system ?
I have the following brand

Bryandt 698B

I have vents closed to my 2 other bedrooms (400sq ft each) and the space I heat up is living room, upstairs bedrooms and 2 bathrooms. The total space is (3 BR/2BA, 1850 sq feet)

Also the humidity in my house is 27% …which is a little too low . It looks like that model does not have a heating humidifier …it has cooling humidifier though ;-)
any idea how to increase it without investing thousands into new equipment ?

[paul52446m]

Here is a situation with my AC unit (fan outside the house). The average temp outside is 30 degrees. I keep temp inside the house at 74 degrees constant. I do not have any pre-programmed time schedule when temp should go up or down .. If I leave the house the temp drops top 61 and then the system turn on .. when I come back from work ..I set the time on 74 (hold on 74) and hold it for 14hrs …it takes couple of hrs to get from 61 to 74

The problem is that the fan outside the house seems to be working all the time ..it stops very rarely and sometimes there are some weird loud sounds (lasting no longer than 5 seconds) coming out of it ..
I observed that the furnace heats up the air and ..when the furnace stops working the fan keeps on going on pushes cold air from outside the house for some time..it does not get cold or anything but I think the …the temp drops and furnace goes back on …

Can you pls let me know whether there is something wrong with the system ?
I have the following brand

Bryandt 698B

I have vents closed to my 2 other bedrooms (400sq ft each) and the space I heat up is living room, upstairs bedrooms and 2 bathrooms. The total space is (3 BR/2BA, 1850 sq feet)

Also the humidity in my house is 27% …which is a little too low . It looks like that model does not have a heating humidifier …it has cooling humidifier though ;-)
any idea how to increase it without investing thousands into new equipment ?

i am assuming you have a heat pump. The fan out side should not run all the time. I don't see where you are getting outside cold air into the home, your air handler or furnace just moves the air that is in the home. You could have a small fresh air intake coming from outside. Your inside blower should not be running all the time unless you have it turned to continues at your stat.
I think you should should have a service tech check over you system. Later Paul