Tube dripping into bilge. Fridge condensation, or ???

[saltymetals]

Some of you might have come across this problem already.

For a number of years the tube leading from the two fridge drains to the bilge has been dripping. I thought nothing of it until the drip turned into a regular flow and had emptied two of my fresh water tanks into the bilge (while the auto-bilge-switch was not working). After pumping out my bilge and fixing the auto-switch i turned the water pressure pump ON again. More water in the bilge! Then the challenge is to figure out where thedevil the leak is, somewhere hidden under the floorboards. But....... i found that the water was HOT! So made a bee line for the hot water tank. The pressure relief valve was leaking and it is plumbed into the drain tube for the fridges.

This meant it was absolutely impossible for me to use the fresh water system in the boat unless it was fixed. 


I did a big search for a new valve but the manufacturer (Braukmann in Germany) has changed the design so the new valve will not fit on the old brass fitting. You could change the brass fitting which comes with a pressure relief valve included but there is another simple, elegant solution. If you have an old inner tube from a bicycle you can cut a rubber disk out of it and super-glue it to the face of the valve where the previous rubber seal has failed. Fixed!

Andrew
"Genial Bee"  

[seattledale]

Andrew

Thanks for your posting; I have had the same problem for the past year.  I will attempt the repair as you described this winter.  My leak from the hot water tank is very minor and I have lived with it by simply de-pressurizing the water system when leaving the boat.  However, the most annoying aspect of it was the bilge pump cycling ALL NIGHT LONG while aboard.  As you know, the bilge sump is of very small volume.  The switch would trip the pump on, the pump would run for about 5 seconds and lower the water level such that the switch would shut off the pump.  Trouble is, the hose length from the bilge pump to the overboard discharge is so long, the water would seldom make it all the way out.  When the pump shut off, the water in the long hose would slowly run back into the bilge over about half an hour, leaking slowly through the one-way check valve near the pickup hose in the bilge. Then the switch would turn on the pump again.  I cleaned the check valve a number of times but they are never perfect. 

I finally got clever and bought a multi-function relay from Amazon ($34) and wired it as a one-shot timer.  When it receives a signal from the bilge switch it closes its contacts for a set amount of time.  I dialed in the relay to hold its contacts closed for an additional 10 seconds after the bilge switch has opened, which is enough time for the pump to completely drain the sump and suck air, thus purging the long discharge hose of all water.  It didn't fix the slow leak from the hot water tank but at least the pump would only run once a day rather than cycling every half hour.

But I will try your repair on the hot water tank which should fix the root cause of the problem.

Best regards,

Dale