Bilge Pump Hose Exhaust Location

Jon W · May 24, 2016, 10:28:29 AM

The recent post about bilge pumps reminded me of a question I had for everyone.

For those with bilge pump hose(s) that run aft, do they exit through the transom or through the hull where the cockpit drains connect? If through the transom, hi or low? Thanks for the help.

Dave Spencer · May 24, 2016, 11:27:35 AM

Jon,
The bilge pump hose on my Mk1.5 exits through the ransom right on the centreline just below the swim platform / sugar scoop.

Ron Hill · May 24, 2016, 01:46:59 PM

Jon : The electric bilge pump exit on a MK I with a standard transom -- is on the starboard side of the transom about halfway between the center and the edge, about 3 to 4 inches above the large manual bilge pump exit (that's in the low center).

That was where the factory installation was!!

Stu Jackson · May 24, 2016, 02:34:12 PM

Quote from: Ron Hill on May 24, 2016, 01:46:59 PM
Jon : The electric bilge pump exit on a MK I with a standard transom -- is on the starboard side of the transom about halfway between the center and the edge, about 3 to 4 inches above the large manual bilge pump exit (that's in the low center).

Not so quick.

I have an electric pump and the manual one in the cockpit. I have only ONE hose outlet, and it is center-line on the transom at the bottom edge. I have traced the hoses and my electric pump hose goes to the manual pump and then out. I do NOT have two bilge pump thru hulls on my boat.

While some may say this is odd, it has been working for the past 18 years. My guess is that the PO simply installed the eletric pump at the end of the existing hose.

In a more perfect world, I'd do what Ron suggested. Never got around to it.

Ekutney · May 24, 2016, 08:54:06 PM

I installed an electric bilge pump and routed the new 1 1/8 hose through the manual bilge pump located in aft cockpit, just like Stu's. Works just fine and the manual pump works as well.

Ed Shankle · May 25, 2016, 03:01:05 AM

I've got two separate exits, one for the manual, one for the electric. As I read the other responses, I wondered if running both thru the manual hose would help prevent syphoning back in due to the high mounted manual pump. Also wondered about the impact on the electric pump having to overcome that height. I assume since Stu has had it that way for so long, must not be an issue. Any additional details on either of those points?

Ed

Ekutney · May 25, 2016, 07:35:08 AM

Ed,
Your thought on having the high entry termination of the electric bilge pump is one of the major considerations I had for routing through the manual pump. The exit point is down low which could be an issue in a following sea if it went directly to an electric bilge pump, unless a check valve was connected in line (which is not recommended but can be needed at times). I installed a Rule 1500 which has no problem overcoming the additional 2 ft lift by routing through the manual pump.

Hats off to Stu because I contacted him directly and he explained his configuration. I tested the manual pump, it is able to pass the output through it and even has a check valve preventing back flow. Plus the manual pump can use the electric bilge pump pickup so this configuration does allow both pumps to be used with a single hose and thru hull.

Jon W · May 25, 2016, 04:20:57 PM

How did you connect the 1 1/8" hose from the electric pump to the 1 1/2" connection on the manual pump?

Stu Jackson · May 25, 2016, 06:40:21 PM

Jon, I must admit I do not know. The electric bilge pump is connected to the corrugated hose, and then it goes up to the manual pump. Been that way since I bought the boat in '98. I'll go look around.

Noah · May 25, 2016, 07:05:22 PM

I'm bit confused (nothing new there) are you saying the electric pump tees into the manual pump's discharge hose with each pump still having its own separate suction/intakes? Or something else? Also, Jon, I thought you had, or are planning two electric pumps? If so, how are those plumbed?

Stu Jackson · May 25, 2016, 07:22:51 PM

Quote from: Noah on May 25, 2016, 07:05:22 PM
I'm bit confused (nothing new there) are you saying the electric pump tees into the manual pump's discharge hose with each pump still having its own separate suction/intakes? Or something else?

I was confused, too, until I looked. Electric pump >>> hose >>> manual pump >>> hose >>> thru hull.

Jon W · May 25, 2016, 08:06:41 PM

Hi Noah,
I have a manual Whale pump in the cockpit, and a Rule 1500 with a float switch. I will be adding a Rule 3700 with float switch. I was curious what others had.

The Rule 1500 has a 1 1/8" hose runs to a thru hull mounted high near the starboard backstay chainplate on the transom. I've counted three check valves in this hose run. All will be removed. The manual bilge pump has a 1 1/2" hose run from the bilge to the pump and then to a 1 1/2" thru hull bottom center of the transom like Ron described.

Still thinking about the new installation. The current idea is to put a 1 1/2" Whale y connector in the manual pumps output hose to join the manual and Rule 3700 pump hoses before the 1 1/2" thru hull. I may add anti siphon valves to the electric pump hoses.

Just noticed that the propane locker drain hose connects to a thru hull a few inches directly above the 1 1/2" bilge drain thru hull. Also can't find any communication path between the main cabin and the bow if there is a leak under the V-berth. Nothing is easy.

Ekutney · May 25, 2016, 09:04:34 PM

My configuration:
Rule 1500 with 1 1/8 in hose to Whale manual pump input with 1 1/8 to 1 1/2 adapter output of Whale 1 1/2. Hose to thru hull. I am considering another backup bilge pump using either another Rule 1500 or 2000. Each bilge pump will have a dedicated external float switch.

Noah · May 25, 2016, 09:43:21 PM

Llet me see I have this correct. Stu tees the electric pump discharge into. The Whale manual pump's DISCHARGE hose, while Ed tees into manual pump's SUCTION side--both only use a single discharge thruhull? Ed, no problem discharging THROUGH the manual Whale pump? Doesn't the Whale pump's "innards" impead the electric pump's discharge or does it pass right through?

Ekutney · May 25, 2016, 10:14:41 PM

Noah,

I didn't T the electric bilge pump into the Whale, my bilge hose comes directly from the electric bilge pump. I have a single bilge hose. The Whale uses the pickup from the Rule when it is off and the Rule passes water right through the Whale when it is on.

I actually tested it and the flow is not impeded at all, the built in flapper valve at the output of the Whale seems to have no restriction at all. The Whale pump just passes the input water right through. The location of the Whale plus the output flapper does not allow any back flow in a following sea. I thought it was too simple but this configuration works. I spoke to a number of people and even visited a local marine store, they agreed with my testing and one very senior gentleman said he has seen this done a number of times and asked who told me about it. One of the very few times I was surprised how simple the final solution to a potential complex plumbing issue was resolved. I was thinking of using a second bilge hose in a Y configuration with check valves but ended up returning a number of items.