Ac run without pump

[UNIQUE_NAME]

Old crusier unit split reverse cycle system 3 knob control. Friend ran it for about 5 mins with no water pump.
Now only warm air coming out so he turned it off. Is there hope for it this weekend if the unit cools down? I don’t know acs at all. Thanks.

 

[Captain Ralph]

There is usually a low pressure switch on all systems. Most, not all have a high pressure switch. Running without water and the compressor running would cause a high temp/high pressure issue. With the pressure switch, the compressor turns itself off, then back on, then off, then back on , off ,on,,,,,

With out this high pressure switch, damage some times happens. How long was that 5 minutes really??
Do you have water back to it yet?

 

[zigzag930]

Generally no damage should occur. Virtually all of these compressors will protect themselves from high pressure by cycling the compressor off when the head pressure gets too high (from lack of water, etc).

As long as you now have proper water flow (and don't need to bleed the system) the compressor should be fine.

Turn the unit to "Start" and verify water flow overboard. Then turn to "RUN" and you should be fine. If you don't have any water flow overboard, you may need to bleed the system.

 

[UNIQUE_NAME]

It was really about 5 mins without water before he realized it.
Then he turned the pump on. Once he turned the pump on still only warm air.
Then he turned the unit off. He just tried it again with the pump on, still only warm air. This is after about 2 hours off.

 

[zigzag930]

If still not cooling (and you have verified water is flowing overboard) check to see if the compressor is starting when setting the controls to the "RUN" position. 2 hours should have been plenty of time for the compressor to have cooled down.

If you do you have good water flow and the compressor is running, feel the condenser coils (they wrap around the compressor on most systems). See if they are cold, warm or hot. They should be warm if the water if flowing properly, the charge is correct and the compressor is pumping properly.

Report your findings

J

 

[Captain Ralph]

It was really about 5 mins without water before he realized it.
Then he turned the pump on. Once he turned the pump on still only warm air.
Then he turned the unit off. He just tried it again with the pump on, still only warm air. This is after about 2 hours off.

Ensure thermo stat in turned to cool. I'm sure you have done that but had to make sure.
If water is flowing, check that the compressor is starting and continues to run.
There is also a over heat switch on the compressor. Several minutes is all needed for it to close.

The next flow chart steps depends on if the compressor is running or not.

 

[UNIQUE_NAME]

Pipes are warm. Top of compressor is hot. Water is flowing.

 

[zigzag930]

When was the last time you know for sure the system was blowing cold?

If the water is flowing, but compressor is running but HOT - you may be low on refrigerant. One of my systems has a slow leak and I need to charge it every 9 months or so. I have the gauges, R22 and knowledge to do that.

Sorry to say, but I believe we've checked all the easy stuf. At this point I'd suggest you find a qualified HVAC tech to check things out with a gauge set. Small cost to find out what's going on and probably worth it to prevent any additional damage.

 

[zigzag930]

A few additional Q's I just thought of:

Does this AC unit go to it's own thru-hull for discharge or does it share a sea-chest with other AC units?

Does this AC unit have it's own seawater pump or does it share a pump with multiple AC units?

When you say the compressor is hot, how hot? Can you keep your hand on it? Does it cycle off or does it stay running?

 

[UNIQUE_NAME]

It was ok Last weekend. He made a call and is going to pick up a friend with gauges in a little while.
We have been relieved of duty. Thanks for your help.

 

[zigzag930]

Let us know what he finds.

Good luck

 

[Pascal]

First make sure there is a bough flow. Then reset the Hi Pressure switch, it’s attached to a gas line near the compressor and has a reset button on it. Newer electronic control units donit electronically but older units usually have a manual switch

 

[UNIQUE_NAME]

final outcome:

his friend showed up with gauges and a tank.
system wouldnt hold refrigerant, there is a leak somewhere.
running without water was just bad timing, leading us astray.

thanks to all.