MH37 Aft A/C drain

[Boomer54]

I have a 2014 MH37. According to the Owners Manual, the aft unit (in the aft cabin) is supposed to drain in the bilge. The spot where the manual shows it entering the bilge is not where it actually enters. In fact, I cannot find where it does actually drain! I can trace the drain tube from the drain pan around the the unit heading aft, turning port and the turning back forward. Basically it is following the a/c unit base around to aft and back to port. It then dives down a small hole with both the raw water intake and raw water discharge and electrical conduits. It is too tight to get your head back there. I initially used my camera to figure all that out. I also just finished using. 39” fiber optic camera trying unsuccessfully to get it down the hole and figure it out. Bottom line, I am 99% sure it doesn’t drain into the bilge. Does anyone know where in fact it does drain??

 

[Bob R.]

Boomer, I have a 2018 MH40 with the same aft AC unit. The condensate drain is routed to the aft shower drain sump box. The problem is that all of the drain line routing turns, including the turn to get the drain line under the shelf in the cabinet where the AC unit is mounted, created a high spot in the drain hose that resulted in the condensate pan overflowing before it could drain to the sump. I tried to reroute to drain hose to no avail. I contacted M-H and asked them to buy me a Venturi condensate removal kit made by Marvair and offered by Dometic as an accessory. I also sent them a link to the Marvair CR330 Kit offered for sale by Defender for $136.99. They bought it for me and I installed it over a year ago, it works great. No more condensate leaking onto the aft cabin floor.
Bob R.
Chasseur MH40

 

[Boomer54]

Boomer, I have a 2018 MH40 with the same aft AC unit. The condensate drain is routed to the aft shower drain sump box. The problem is that all of the drain line routing turns, including the turn to get the drain line under the shelf in the cabinet where the AC unit is mounted, created a high spot in the drain hose that resulted in the condensate pan overflowing before it could drain to the sump. I tried to reroute to drain hose to no avail. I contacted M-H and asked them to buy me a Venturi condensate removal kit made by Marvair and offered by Dometic as an accessory. I also sent them a link to the Marvair CR330 Kit offered for sale by Defender for $136.99. They bought it for me and I installed it over a year ago, it works great. No more condensate leaking onto the aft cabin floor.
Bob R.
Chasseur MH40

I suspected the shower sump may be where it drains! I’m not at the boat until next week. I guess I will tear into the shower sump area to see what I can find. The shower sump is not what I’d call easy to access. I will also have to start watching the drain pan itself as I haven’t up to this point in time! Btw, my shower sump is on a manual switch, not a float. Yours?

 

[Bob R.]

Our aft shower box is not on a switch, in fact does not even have a dedicated breaker. I think it was done that way because both of the AC condensate pans drain to the sump box. The sump box for the forward head does have a switch in front of the vanity. The problem with that one is it also serves the vanity sink (no dedicated through hull). We taped the switch on, because we always forget to turn it on when using the vanity sink and the box overflows into the bilge. Both sump boxes have Rule pumps with separate float switches. Water level in the box have to get about 2/3 full for the pumps to turn on and only stay on for about 1 second, so cycle frequently when needed and leave the boxes 2/3 full when finished. They spill into the bilge when the boat heels. We can also hear the pumps running when the boat heels.