AC quit working

[JasonRW1910ESP]

Our brand new rockwood 1910’s AC has been having trouble the last two trips. After running for a few hours, the AC stops working and barely blows any air at all at any setting. The unit is not frozen over, running on shore power. After turning it off for a few hours, it works again. Outside temp is about 88 during the day, 65 at night. What are some troubleshooting suggestions??

[rockfordroo]

It sounds frozen to me. What makes you think it isn't?

[JasonRW1910ESP]

Looked at the unit and not frozen on the coils .

[TitanMike]

If the blower is turning at regular speed and air flow is greatly reduced that's usually a sign that the evaporator is iced up.

Are you sure you aren't looking at the outside "coils" which are the condenser coils where heat is exhausted from the system. Evaporator is harder to see as it's buried inside the unit.


If you have the fan set to low, try starting out with the fan on High and see if it still quits blowing air. Also, if there is an air filter in the system make sure it's clean.

Icing occurs when humidity is high and air flow is insufficient to provide enough heated air to keep the ice from forming.

My wife's old car had an automatic fan speed control. As we'd drive through humid parts of the country the air would slow from the vents, eventually feeling like it stopped. I'd manually turn the fan to max and after a few minutes it would start tossing little flakes of ice out the vents at us.

Many turn the fan to low at night because of the noise but if the humidity is high this can cause the problem. Some units have an anti-icing feature which usually just turns the compressor off for a short period to let any ice that has formed, melt. If your A/C is equipped with that feature, it could be faulty.

Check manual for troubleshooting tips (online if you can't find one that came with unit).

[rockfordroo]

Originally Posted by TitanMike

If the blower is turning at regular speed and air flow is greatly reduced that's usually a sign that the evaporator is iced up.

Are you sure you aren't looking at the outside "coils" which are the condenser coils where heat is exhausted from the system. Evaporator is harder to see as it's buried inside the unit.

X2

See pic. To see the evaporator, you have to either drop the ceiling shroud inside the TT or remove the outside cover and then open up the air plenum. Depending on make, you MIGHT be able to see it if you can remove the filters, but it's still difficult.



Icing is discussed on page 3 of the attached manual:

II. Operation During Cooler Nights (Cooling
Operation).

It is important, when the outdoor temperature drops in the
evening or during the night to below 75 degrees F., that the
thermostat (temperature control) be set at a midpoint between
“Warmer” and “Cooler”. If the setting is at “Cooler”, the
evaporator coil may become iced-up and stop cooling. During
the day when the temperatures have risen above 75 degrees F.,
reset the thermostat switch to the desired setting.

NOTE
Should icing-up occur, it is necessary to let the cooling
(evaporator) coil defrost before normal cooling operation is
resumed. During this time, operate the unit in the “HIGH
FAN” position with the system at maximum air flow. When
increased or full air flow is observed, the cooling coil should
be clear of ice.

Also, some AC units have an icing sensor that's supposed to shut off the compressor if ice is detected; some forum members who have had icing problems have subsequently reported that the sensor had shifted or fallen off the evaporator.

[Mike91]

Yep, my AC iced up when temps dropped to around 75 degrees. I just turned AC to high fan only for about 30 minutes, then back to the high fan cooling. Problem fixed and back to normal.

[JasonRW1910ESP]

Had no problem with the AC last night.

[Mike91]

Originally Posted by JasonRW1910ESP

Had no problem with the AC last night.

Good, maybe just icing up then.

[JasonRW1910ESP]

Man I hope so. I don’t want problems this early on a new rig.