Twin Bilge Pump Plumbing

[Limbofish]

I have recently installed another bilge pump on a separate electrical line, toggle switch/breaker on my panel. This is a backup pump with no float switch. I didn't want to put another hole in the boat for another discharge hose. The sales guy said to install a Y connector and tie in both pumps discharging bilge water out 1 hose. Only problem is that when 1 pump is activated, the water returns through the Y hose, goes out the other pump bottom back into the bilge. No water is pumped out. Both pumps need to operate in order for water to be pumped out.

Can somebody offer pictures and/or instructions of the correct method to plumb 2 pumps? Should a check valve be used? What kind?

[captwally]

Check valves will help ( no backflow) but, depending on how far apart the pumps are, you could also wire the float switches and pumps to one another so that both pumps run at the same time. My engine room pumps are set to run together (old Hatteras), but it could be a problem if one gets stuck the other may burn out too.

[knotreel]

I would add another hole. whY connection? if you want real redundancy make the plumbing seperate. Stuck check valves could render both of your pumps useless. don't trust you saftey to a coulpe of check valves

[jsmith89]

I would add another hole. whY connection? if you want real redundancy make the plumbing seperate. Stuck check valves could render both of your pumps useless. don't trust you saftey to a coulpe of check valves

I agree the Y adds 3 more plumbing connections which are the biggest sources of failure. A good through hull with a quarter turn ball valve is a lot more reliable in my opinion.

[30Tournament]

I have recently installed another bilge pump on a separate electrical line, toggle switch/breaker on my panel. This is a backup pump with no float switch. I didn't want to put another hole in the boat for another discharge hose. The sales guy said to install a Y connector and tie in both pumps discharging bilge water out 1 hose. Only problem is that when 1 pump is activated, the water returns through the Y hose, goes out the other pump bottom back into the bilge. No water is pumped out. Both pumps need to operate in order for water to be pumped out.

Can somebody offer pictures and/or instructions of the correct method to plumb 2 pumps? Should a check valve be used? What kind?

I don't think your setup is safe, it likely puts both pumps at risk of not working right. However, if this is really the way you want to go, I think if you placed the y vertical with the outflow at the bottom and with a foot or so of each pump hose above the y, it would work.

[triumphrick]

We just did this to my buddys Pro Line that will be kept in the water. We added a 1500 gph and popped another hole for the second pump drain hose. Drilled from the outside, used a hole saw, light pressure and make sure not to drill through anything inside! Good luck

[Joenic]

You need to add another hole. two pumps will not or can not pump out twice the water through one hole. Now if one is considered a back-up, fine, go with the y valve and a check valve, but if you want two pumps to run simultaneously, then two holes are a must.

[CaptnC]

then two holes are a must.

I agree with most of the guys in this post...you need a second hole. Most discharge hole are high enough that they don't really count as a "though hull" hole. I installed a second pump in my boat last year after a buddy sank his boat. I also spent a little extra and got the brass outlet fitting too. With it being a safety backup I didn't want to take the chance that a plastic one would break and not know it until I needed that pump!

[whotookmyhandle?]

Please use a second discharge hose and side hull. Also please make sure that both pumps are wired to separate battery banks and are correctly fuse protected.

The side hull discharges must be 12" or greater above the static water line and incorporate a loop in the hose above the fitting to prevent siphon action.

[oceandansar]

put another hole please