Bilge Pump Check Value Required?

[Edward Duhe]

I am having trouble with my bilge pump. I just purchased a 1984 Hunter 34 and knew that the bilge pump was not working. It didn't seem to suck the water up. So I bought a new bilge pump (Rule 1100 GPM) and found I had the same problem. With no hoses on the pump it picks up a prime and pumps fine. I notice there is a check value or backflow preventer in the discharge line. It appears to me that the problem is the bilge pump does not generate enough pressure to push the water through the check valve. I can use garden hose pressure and get the water to flow through the valve but again it does not seem the bilge pump can do it. The local marina personnel suggested I just remove the check valve as they say it is not necessary. I hesitate to do this as the run for the discharge hose is fairly long and I can see that when the float would turn off the pump that the remaining water in the hose would just flow back and probably kick the pump on again. Does anyone have information about this check valve and if it is necessary on the Hunter 34? Any suggestions on where I could find a replacement?Thanks for any help, would sleep better if my automatic bilge pump was actually working .Edward

 

[Barry]

Check Valve is Necessary

I have one on my 1983 h34. Because of the length of the hose and the size of the bilge the pump would cycle all day if the check valve wasn't there. I think my pump is a Rule 1500 but it has no problem working with the check valve. I have at times had to disassemble the check valve and clean it.Barry

 

[Greg]

Sorry barry, but I disagree....

no need at all for a check valve, most "experts" will agree, which is why you have your problem, take the check valve out and save your sinking ship!Greg

 

[Kevin Whalen]

Try It and See

I agree with Greg. Your safer and better off with out it; but if your pump continues to cycle do to back flow than leave it on. My 40 had check valves on the bilge pumps when I bought it and I had the same problem you having. So I removed them; the pump works great now. I get some back flow but not so much that it turns the pump back on. So I say try it out. If it works with out the check valves great. If you need them, due to back flow, clean them and put them back.Kevin

 

[Peggie Hall/Head Mistress]

The right solution

IMO, a check valve in a bilge pump hose is just asking for a sunk boat if the bilge pump is ever needed to get rid of water when no one is aboard.If the bilge pump hose is routed to allow too much water to run back from the thru-hull, the proper solution is, reroute the bilge pump discharge hose to put a high loop--high enough that the route from the top of the loop goes downhill to the thru-hull--in it as close to the pump as possible. The backflow from the top of the loop will be less than a pint, which isn't enough to cycle your bilge pump and little enough that you can--and should--mop up easily to keep your bilge dry.That doesn't mean that your bilge won't EVER cycle...an effect known as "ram water" can force water back up the hose and over the loop when you're heeled and screaming along. But your bilge pump can handle it...just don't panic if you hear the bilge pump cycling when you're out sailing.

 

[Steve Dion]

I wouldn't have one either.

Edward:I would not have one either. Most boats are going to send a tube full of water back into the bigle once the switch turns off. If this is a problem, then sponge out the bigle. I would figure out where you water is coming from if you want a dry bigle. You can get a shaft seal and probably eliminate most if not all the water intrusion.

 

[Edward Duhe]

Thanks to everyone. I'll try it.

Thanks to everyone. I am so impressed with this forum. I will try taking out the valve and see how it goes. I really appreciate your advice.Regards,Edward

 

[Bruce Hill]

Peggy- a follow up question

Peggy-you wrote "IMO, a check valve in a bilge pump hose is just asking for a sunk boat if the bilge pump is ever needed to get rid of water when no one is aboard."Please explain/clarify for me. Why is a check valve such a danger?Thanks!

 

[Clyde Lichtenwalner]

Check valve danger

The check valve will fail closed or clog and the pump will either not pump, or the check valve will leak causing pump cycling. The check valve is a restriction in the discharge line even when it is working properly. Bilge pump cycling on the H-34 is inevitable without a check valve, unless other measures are taken, because of the hose diameter and length of the hose. The bilge sump is just the wrong size and shape. The solution is to remove the check valve and raise the on-off switch higher in the bilge. I put plastic spacers under the switch that raised it about 2" higher.Next, buy the smallest self contained pump you can find. I got a rule computer-controlled pump in the smallest size available. Using the smallest diamater hose that fits the pump, run the discharge aft to share the large bilge pump's thru hull, or better, install a new thru hull fitting near the existing pump discharge thru hull. The large bilge pump should never turn on except when the water gets extraordinarily deep. Of course, the small pump cycles on the computerized schedule, but this does not seem to cause a problem. Before I leave the boat, I always sponge the bilge dry if necessary (that is almost never). When aboard I ususally turn the small pump off to save power and avoid the annoyance of the comuterized pump cycling on and off. The result is additional electric pumping capacity, lower water level in the bilge (when there is water there), a main bilge pump switch that almost never operates (and lasts longer), and a large pump that you can count on to empty the bilge when it is most needed. For a really scary exercise, take your shore water hose and run it into the bilge. See if the bilge pump keeps ahead of the flow. For another sacry exercise, imagine you have been hit by lightning and the 12v system does not work. You are now pumpless unless you have a good manual pump. The H-34 did not come with a manual bilge pump,so if you don't already have a good one, get one.

 

[Mike Busher]

Electronic Bilge Pump Switch

The bilge pump on our Hunter 420 did not have a check valve and came on very often when sailing. Also had problems with the float switch sticking in the on position. I thought about a check valve,but worried about the possible problems. Instead, I instaled an electronic switch (no float) with an 8 second delay. This prevents cycling quite effectively. Also appears to be quite reliable as it has no moving parts. Available at Boat U.S.. Identified as "See Water Water Smart Pump Switch.