basic help a/c

[SonofaWhatthe]

I will start with overly simple dialog since I'm out of my element. The outside thing makes noise (it's not blowing out hot air but it's blowing out neutral air to my thinking). The inside thing makes noise... and yet no cold air is moving through the vents. The registers are cold but no air is flowing. Why does the furnace "thing" make noise and yet no air is moving???

[jumptrout]

You probably have a restricted evaporator coli in the inside air handler unit.

The restriction is probably a coil that is frozen over.

If you van verify the indoor fan motor is in fact running,set the thermostat in the FAN ON position.

Set the HEAT/Cool setting to OFF.

Run the system like this until air begins coming from the vents.

You will need a technician to check the system refrigerant charge.

Low refrigerant will cause the air handler coil to freeze over.

Dirty coils will freeze over.

Bad fan motor not moving air will cause coils to freeze over.

[RegUS_PatOff]

The outside thing has a Compressor and a Fan ..

You may be hearing the Fan, but the Compressor may not be running

[SonofaWhatthe]

Thank you both. While I was away today a "tech" came by and confirmed that we had freezing going on (somewhere) and that my mother in law needed to let the thawing, etc.. happen. We also had a dirty filter that needed replacing. He said that M-I-L had left it turned down too low which led to the problem.

 

So after those fixes we are back in business. I wonder if for how long given your suspicion that refridgerant may be low. We have set it down to 71deg and will watch what happens. The fan was blowing most of the day without the cooling on so I'm sure we are thawed out for now. And we replaced the filter.

 

This tech told M-I-L to keep the vents closed in the basement and then open them in the winter. I was surprised as I've read in nearly every other place to keep the system open even though you hate pumping that cold air into the already cool basement. Are there certain systems where closing the basement vents is actually best practice and this tech had savvy or was he, as I suspect, using common sense and not professional sense. The tech was a friend of my sister in law and works on general maintenance and HVAC in the restaurant industry but isn't a true HVAC serviceperson.

 

Thoughts? 

 

Thanks again for the help!

[jumptrout]

Closed vents contributes to restricted air flow.

Newer smart systems with zone dampers and variable speed motors adjust for this restriction.

Older single speed systems do not.