Anyone Know Anyone In HVAC? Question...

[AKL_Megs]

My own dad is in HVAC, but I haven't been able to get ahold of him all last night or today, of course.

Does anyone have any idea why our system would be doing this...

When the AC is on, it will run for a while, but then the blower fan (on the furnace) will shut off for a few moments (while the AC outside continues to run) and then, suddenly, turn back on. It comes on fine, and turns off fine when it gets to temperature and everything (other than the weird "turning off" for a few moments, and then kicking back on.)

It started doing this last night, so we shut it off and opened windows. This morning we turned it back on, and it was fine all day, but it just did it again.

Any ideas?

 

[buckler]

Did you look to see if it is icing up anywhere? That might take all day to build up. Or could a belt be slipping on the blower fan?

Another thought, the blower motor may be overheating and cutting off (they have safety cutoffs). When it cools down enough it can kick back on.

When was the last time you changed your filter?

 

[Art 1]

Bad motor capacitor, bad fan relay, loose wire would be the main thing to look at.

 

[Familycircus]

Agree with Art1. In the meantime, change filter, check inside coil for icing. Maybe try switching the thermostat from "cool" to "off" and the fan from "auto" to "on".

 

[momrek06]

Have you had a maintenance check on the A/C system? You should have your HVAC man do a Preventative Check yearly on the system. It could even be something as simple as dirt and dust in the system.

 

[disney1990]

Sounds just like what our system is doing -- and yes, there is ice building up. We need a valve replaced and hopefully the part will be in tomorrow -- we have been waiting a week for the part.

 

[Familycircus]

If there is icing, it must be completely thawed for it to be serviced so the tech can get the proper readings of the system. If the inside coil is iced then you could run the furnace fan on constant to thaw the iced coil.