I'm planning to install new bilge pumps on my 33' Pearson. I read where it's highly advisable to have multiple pumps that all combined discharge at least 3000gph for a boat this size. I'm considerring the RULE "Automatic" pumps but understand that they self cycle every couple of minutes. Are they silent or am I going to have to hear them cycle on and off all night?
Automatic Bilge pump question
- Thread starter Chesapeakegem
- Start date
- Status
You will find lots of threads on the subject with the search function.
Buy the smallest and cheapest pump you can and put it in the bottom of the bilge. Consider one of the solid state water sensing switches instead of a float switch. This will take care of condensation, ice box melt, etc.
Install a big pump or pumps with a plain float switch(s) a couple of inches higher so it always stays dry and it's float switch won't come on unless water is coming in fast enough to overwhelm the small pump. By keeping the "save the boat pump(s)" dry and not having its switch(s) cycling for routine duty, you'll be sure they will work when needed and won't be buying expensive pumps every couple of years.
The discharge line for the small pump can "T" into the larger pump discharge lines just before the through hull.
Be sure to research proper discharge line runs, don't use any check valves, install vented loops, etc.
Buy the smallest and cheapest pump you can and put it in the bottom of the bilge. Consider one of the solid state water sensing switches instead of a float switch. This will take care of condensation, ice box melt, etc.
Install a big pump or pumps with a plain float switch(s) a couple of inches higher so it always stays dry and it's float switch won't come on unless water is coming in fast enough to overwhelm the small pump. By keeping the "save the boat pump(s)" dry and not having its switch(s) cycling for routine duty, you'll be sure they will work when needed and won't be buying expensive pumps every couple of years.
The discharge line for the small pump can "T" into the larger pump discharge lines just before the through hull.
Be sure to research proper discharge line runs, don't use any check valves, install vented loops, etc.
Last edited:
Two pump combo is best for bilges.
I use the smallest pump for 'maintenance' extraction of bilge water .... you wont hear such a pump, especially if the leak rate of your stuffing box is correct (at about 1-2 drops per minute .... thats 2-4 cc's of water per HOUR). The smaller the 'maintenance' pump, the smaller the hose 'capacity'; hence, the less 'drain back' when the small pump shuts itself off.
The LARGE pump is to prevent SINKING and you dont care how much water its pumping if you are SINKING.
Set the suction inlet to the large high capacity pump higher than the 'maintenance' pump. ... and put an audible 'bilge alarm' on the High Capacity Pump ... as you WANT TO KNOW when this pump is on.
I use the smallest pump for 'maintenance' extraction of bilge water .... you wont hear such a pump, especially if the leak rate of your stuffing box is correct (at about 1-2 drops per minute .... thats 2-4 cc's of water per HOUR). The smaller the 'maintenance' pump, the smaller the hose 'capacity'; hence, the less 'drain back' when the small pump shuts itself off.
The LARGE pump is to prevent SINKING and you dont care how much water its pumping if you are SINKING.
Set the suction inlet to the large high capacity pump higher than the 'maintenance' pump. ... and put an audible 'bilge alarm' on the High Capacity Pump ... as you WANT TO KNOW when this pump is on.
Good point. Be sure to include a shut off switch for the bilge alarm though as every bit of battery capacity will be precious. Not having the alarm going may also help you think through finding out where the water is coming from and better communicate emergency instructions. The alarm should be loud enough that people will be running around trying to figure out how to get it shut off if you are not on the boat.
Speaking of electrical, the big bilge pump(s) should be wired directly to the batteries ahead of the main battery switch and have no way to turn them off except by removing the fuse. The reason for using a float switch on these pumps is so that it can be lifted for testing. The less wiring, the better on these pumps.
I would suggest that you stay away from these Whale units. VERY NOISEY.
Whale Super Sub Low Profile Automatic Bilge Pump
Whale Super Sub Low Profile Automatic Bilge Pump
That's what I have and yes, they will keep you awake at night. You don't notice it so much during the day when the music is on and you're chatting away with the crew but when everything is quiet, it can be like water torture (pardon the pun). I had to replace mine last year because the impeller broke on the last one. The boat came with this setup and it's on the list of items to rectify but I needed to get something in there so I just went with what I knew I could plug 'n play for the short term.
Thanks all for the outstanding input and advice! "Water Torture" lol, sounds like an awesome name for a boat.
Thanks again!
Thanks again!
- Status