Icebox drain not pumping dru

Mar 6, 2008
Catalina 310 Scott Creek, VA
I have a 2003 hull number 218 which has the ice box (12v fridge) drain to a y-valve under the head sink which is also connected to the shower sump, and drained via a diaphragm pump mounted under the head sink. It will no longer pump the fridge dry. Has anyone had problems with the hose from the fridge getting clogged up? I have been troubleshooting by making sure it wiil pump the shower sump (it does) and removed the hose off the y-valve from the fridge and replacing a short hose to a bucket in the head, which it will pump dry. When attempting to pump the reefer, I can put my finger over the submerged outlet and feel a little suction, but not enough to pull then water out. The y-valve was replaced last season, and it appears that the strainer is not leaking air based on observation with a light when switching between the sump and fridge. I might be able to remove the shelf under the galley sink and hire a long armed ape to see if the hose can be disconnected under the fridge, but was wondering if anyone has had this problem or any ideas? Could the diaphragm pump be the problem and able to pump from a 2 hose to a bucket in the head, but not an 8' hose down into the bilge up to the reefer?


Feb 11, 2017
J/Boat J/160 Annapolis
It's possible you have some occlusion, or build-up of bio-sludge or have induced a crimp in the hose.

Have you tried to back flush the line to the fridge? is the hose line "clear". You can put some hot water down the line -- but I'd take the diaphram pump out of the equation before that.

Have you tried to hook-up a manual pump (like an old brass PAR pump) or a drill pump to suck the line free?
May 24, 2004
CC 30 South Florida
We once inserted a long piece of electrical wire down the drain line and got it unclogged. I think it was 16 gauge with insulation. It was strong enough to be pushed but light enough to bend. Our Fridge drain went to the bilge so really do not know how long the line was.
Mar 6, 2008
Catalina 310 Scott Creek, VA
Leo310, I assume you have a strainer under the head sink between the outlet from the y-valve going to the inlet for the diaphragm pump (also under the head sink)? Benny & SG, thanks for the responses, I will try a back flush and/or snake from the fridge end before I tackle removing the hose from under the fridge drain.


Dec 15, 2006
Catalina Catlina 310 Campbell River BC
No our Y valve is under the galley sink with a strainer for both shower and fridge.
Nov 16, 2012
Catalina 310, 2000, #31 31 Santa Cruz
No our Y valve is under the galley sink with a strainer for both shower and fridge.
The plumbing changed during the production run. Early boats had the valve, pump, strainer, and thru hull under the galley sink. Later boats moved some of that under the head sink. The macerator thru hull also moved around thru time.


Feb 14, 2017
Catalina 310 211 Lake Guntersville, AL
My hull, 211, is the same. I used my little shop vac on the hose end at the strainer, seemed to clean it out.