Level condensers

I see quite a few home inspection reports where the inspector calls out the condenser isn’t level (I’m referring to split systems). I would think you would want it to be sloping a bit toward the drain. Is there I reason that would require it to be exactly level?

A condensing unit normally doesn’t have a drain.

Hermetic compressors in condensing units are “splash oiled” and having the unit level is important to the proper functionality of the splash oiler pickup.

Marc, what about a heat pump?

Same thing, just the direction of heat flow is reversed.

As for level, yes, Marc was correct. A compressor’s major root cause of premature failure is lack of lubrication. This comes from two sources. 1. A leak in the system, carrying away oils/cooling of oils. 2. Unleveled condensers, causing low areas in the sump.



There generally are more than one drain hole in the bottom of the condensing unit. I do not run around with a level in my pocket and have never called out a unit as being unlevel not to say that I wouldn’t if it was grossly unlevel. I see some units that slant with the conture of the landscape slightly but would consider this as cosmetically un-pleasing has nothing to do with the proper operation of the unit. I don’t nit-pick

In our climate we get quite a few winter days when a heat pump will ice up and then have to go through a defrost cycle. On the older houses where the unit is on the roof I often see water dripping off the roof due to plugged drains.

I agree that it should not be grossly out of level for a variety of reasons.

I’ve only called out one or two grossly out of level condensing units in the last couple of years. I use an “approximately 10°” out of level rule:
AC Level.JPG

Some of the packaged outdoor air conditioning units (aka - trailer unit) have the condensate drain run in such a way that it undermines and washes out the unit’s pad. In time, the unit will start to sink right where the condensate line drips off if the line isn’t run away from the pad a bit.

Compressors are cooled by the temperature of the returning freon thru the windings thus keeping the oil at a cooler temp. After having changed out hundreds and hundreds of compressors in my opinion the #1 cause of failure would have to be a dirty condenser not oil failure. The larger% of freon leaks do not have the volume of oil with the freon that would deplete the compressor of oil and cause failure. And I say again you would have to have the unit grossly unlevel to create a lack of lubrication. A Lack of lubrication is most often a result of a washout simply stated liquid freon returning to the compressor and washing the oil from its sump.


Most heat pumps have a preforated bottom that allows for drainage and any installing contractor worth their salt will elevate a heat pump from a flatsurface to allow for proper drainage as this water if allowed to stand in the bottom will freeze every time after a defrost and over time will coat and block the condenser of air flow.

I second Charlie’s posts.

Heat Pumps require proper drainage when they defrost. This is more about “away from the unit” rather than level.

Oil problems occur more from improperly installed line sets with big dips in the run that cause the oil to pool out under low ambient conditions where there is low suction pressures/differential.

That 10 degree picture; I’d be jumping out of my skin over the drainage / foundation issues, rather than an unlevel condenser. If you fix the drainage, the condenser would be leveled.

Compressors which are badly out of level may fail to function properly and need adjustment. Tipping and moving compressors can also cause can cause leaks in refrigerant lines.

A non-level AC condensor will experience more wear and tear on its bearings. At what point does it become a real factor is hard to determine.

I always check to see if the condensor is attached to the pad. If it’s not and the condensor is not level, the condensor can start to “walk” away from the pad and start to put stress on the hoses, etc.

Definitely: The manufacturer installation instructions state that the unit must be level. If it’s not, damage can result. That’s good enough for me.

The reason that I’ve called out unlevel units was because of what I assumed could be undue stress on the fan blade bearing. A defensible idea?

Just depends on your definition of un-level. My personal definition is common sense.

Ask Charlie he may know better, I’ve never seen a leak caused by an uneven condenser. HV/R copper lines are strong enough to hang the residential condenser by and not leak.

Please post your findings!
Some commercial fans are installed on a 45 degree angle.
Motors that are vertical wear the lower bearing first because of the gravity pressure on the bearing. I may be an old dog, but I’m willing to learn new tricks!

David I agree have never observed a leak caused by an un-level A/C unit if they move around from vibration you have a more serious problem than a leak.
I have on numerous occasions when the unit was setting to close to the home scoot it out a bit in order to read the name plate data you can unless the stub out on the copper is to short but if the installer left a dog leg in the lines with any length I will have no problem doing this and I know I am going to be flamed for making this statement. Those copper lines are a lot more flexable than most realize. I am just trying to give examples of how flexable copper lines are.

As to an un-level condenser causing un-do stress on the fan bearings holds no validity with me just not justified in that statement. Take for an example an attic power fan mounted thru the pitch of a 4-12 roof that fan motor is no different bearing or shaft wise than a condenser fan motor so are we going to jack the foundation up to make the fan motor level.

In 37 years of servicing HVAC I don’t recall ever seeing:

  1. A condensing unit without several drain holes.
  2. Damage to any compressor or motors caused by unit being out of level
  3. A loss of refrigerant oil due to refrigerant leaks large enough to cause compressor failure.
    *]A condensing unit “walk” from being slightly out of level.
    Charley definitely knows his stuff on this subject.

“The manufacturer installation instructions state that the unit must be level. If it’s not, damage can result.”

So, are you saying that the listing and labeling on the manufacture instructions is wrong and we dont need to follow it?