AC Water pump circular pump AND check valve

[JGreenwood]

My 2002 Cobalt 360 AC panel has an extra switch that appears to run a pump. Haven’t located that pump yet. I don’t even know if it truly related to the A/C system or not. The local Cobalt dealer has no idea what it is for.

My problems is that the AC cooling pump will work today, but not tomorrow. Sorry, the pump comes on, but does not produce water at the hull output port. The water routing is as follows:
Seacock valve, strainer (cleaned last week and no restrictions), pump (if I disconnect the pump output side, I get plenty of free flowing water), “T” fitting with a Standpipe about 2’ tall with a capped end (have not investigated to see if there is a check valve on the top of the Standpipe. From there it runs along the starboard side of the boat until it gets to the area behind the V-berth seating.

Here is where it gets strange. There is a T fitting, 8” of tubing and another T fitting. From there it runs on to the lower port of the AC condenser unit. After that, it runs from the upper condenser output port thru a check valve (that is not fully checking) and finally to the exhaust port for the AC water output. Those 2 T fittings that I mention at the beginning of this paragraph attach to a water pump; one T fitting to the input of the pump, the other T fitting to the pump output. Essentially a circular pump system the passes thru NOTHING!

The owners manual for the A/C unit show a plumbing system without the Standpipe, without the Circular pump that runs thru nothing, and no mention of a check valve on the output side. I’m sure all of these modification were made with some thought as to help the system work better. I just want my AC water to flow everyday when I turn the system on.

Should I attempt a bypass of the standpipe, circulation pump and check valve and see how that works? Remove one item at a time and see what happens? Replace the check valve and retest the system?

Thanks in advance for any suggestions or comments.

Jeff Greenwood
KNOT FL510
Osage Beach, Mo