Head problems.... 1986 34.5

Oct 1, 2013
5
Hunter 34.5 Lake Norman
I have a 34.5 that seems to operate fine. Additionally, I pumped out my holding tank about 2 months ago. The toilet has been used maybe 15 times since the last pump out and only for #1. However, the holding tank seems to be full. I can fill the bowl with fresh water, flush it down, and it seems to back fill from the outlet port almost to the point of over flowing. This leads me to Believe my holding tank is full again. Could this be true??? Also, I have a mounted black handle above and to the right of my head. Does anyone know what this pump does? I thought it would be a discharge pump from holding tank to the sea, however when I pump, nothing comes out anywhere. The weird thing is, I can tell water or fluid is being pushed through the pump (I can hear it). Not sure where it is going but I know it's headed somewhere. Any information would e greatly appreciated.

JT
"The Pre Nup"
 
Nov 6, 2006
10,085
Hunter 34 Mandeville Louisiana
JT, if (!) the head plumbing is original, the overboard valve has to be opened before pumping out the holding tank manually. On the original, the pump takes suction from the bottom of the holding tank and pumps through a vented loop that goes high up into the cabinet, then back down, through the bulkhead, then to the through hull valve. The backfilling toilet can be due to backflow from the outside flush water, or from the holding tank. A clogged holding tank vent (small hose from top of holding tank to small through-hull) and or a bad joker valve, or plugged hoses will allow backflow from the tank. If the backflow is from the water intake side, it is a bad flapper valve in the head pump control, or a small piece of debris fouling the little valve. Good Luck!
 

splax

.
Nov 12, 2012
694
Hunter 34 Portsmouth
valve closed?, replace pump? which kit?

Hello,
You need to have the valve lever on the head in the closed position or water will flow from the intake and fill the holding tank, siphoning through the pump from sea.
I pumped the overboard pump with the through-hull closed and ruined the pump diaphragm. There is a "replacement diaphragm" thread where I replaced the pump that should have the pump information in it, if you need it.
It sounds like you may need to rebuild the head controls. There is a kit available for a rebuild that costs about $70. The kit needed is determined by the color of the sticker on the head.
 
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YVRguy

.
Jan 10, 2013
479
Hunter 34 Vancouver, BC
You are correct, that handle is the purge pump for the holding tank. If you're hearing water flow through the hose when you pump it that means its working. You likely won't notice anything coming out because the discharge is below the waterline. Also, your tank may be full of mostly water which would minimize any odour you might otherwise expect when you're pumping. I would take the boat out in deep water and pump for a while and see what happens. If it's working you should hear it starting to suck air, similar to the sound of finishing a milkshake through a straw.
 
Oct 1, 2013
5
Hunter 34.5 Lake Norman
Thanks for the info guys. I will be back at the boat this weekend to work on it. I'll let you know what comes of it.