Reverse AC / Heat Operation

[Kai Lani]

Still learning our 2000 380 Aft Cabin. There is 3 reverse air units, 1 in the bow, 1 in the main salon, and 1 in the aft cabin. I was just thinking about the water discharge when one of the units is calling for AC or Heat and the main AC pump kicks on. I am getting a good steady water flow from the rear (port side) through hull, but only a low flow from the bow (starboard side) through hull. It appears the front valve is fully open, just low flow. Is this normal flow?

 

[northern]

Flow in mine is same from all 3. You may have a blockage. Just let the pump run without AC on it might clear things. If not no idea except to clean the line and the AC condencers

 

[tony1b2000]

Agree with northern. I made an adapter and put a garden hose on the input side. Flushed out sand & mud.
The unit is working extra hard with low water flow. Suggest you flush soon.
Alternatively you may have a kink in the water line.

 

[Kai Lani]

Appreciate the responses. Just to be clear, there should be the same amount of flow from both bow and stern through hulls at the same time as soon as any one of the units call for AC or Heat?

 

[b_arrington]

Appreciate the responses. Just to be clear, there should be the same amount of flow from both bow and stern through hulls at the same time as soon as any one of the units call for AC or Heat?

Yes.

If not there is a reduction in the line or the unit.

 

[Kai Lani]

Thanks so much everyone! Will check it out the next time i go to the boat.

 

[Jaybeaux]

@Kai Lani If I understand your layout correctly, you have one AC seacock, one AC strainer, one AC water circulating pump, and then two thru-hull discharges.

On my 420 with similar layout, I would put the boat at a dock where I could reach both thru-hull discharges. Turn OFF the AC, close the seacock and open the strainer. I would then use a rag to help make a seal and put a dock water hose in the outlet of each thru-hull. Definitely a summer time chore as you’ll get pretty wet. My forward engine room bilge pump discharged on the same side. I’d shoot water backwards thru the ACs and flush them to the bilge, then the bilge pumps discharges everything overboard. The first few cycles of the bilge pump were very dirty. I’d keep doing it until the discharge was ‘clean’.

Jaybeaux

 

[Kai Lani]

You are 100% Jaybeaux. Add the fact there are 3 AC/Heat units on the system. Really strong stream out of the aft through hull, and what i would call a low flow out of the bow through hull. Just spotted an odd blue plastic "Flow valve" right at the through hull that appears to be in the open position, but may not be operating properly, and a little difficult to get too. I am going to follow the line back from the bow and check it where i can, and if not, see if there is any way to flush it or reverse flush it like you say. The AC strainer was relatively clean when we got the boat and i do them on a regular basis and don't find much for sea life or sediment. May be a blockage in that front discharge as everyone indicates. This has all been a great help.

 

[Kai Lani]

So i finally got to checking the bow discharge line properly. i actually used a wet vacc on the through hull rather than forcing water back through the AC pump etc with a water hose.. i opened the seacock and turned the front unit on then put the wet vacc into the through hull fitting. It gurgled a bit then started to take in as much water as it would flow. I believe it was just an air lock as it did not vacuum out anything significant. I now have almost equal flow at the bow starboard discharge as i do on the Port stern discharge. One of those rare successful boat jobs... ;o}. fyi... i closed the through hull valve off now and it will only be opened when in use. Such a crazy design to be only a few inches above the water line on the bow of all places. Thanks to those that helped solve the issue.