Bilge pump switch choice

[MSter]

I want/need to upgrade the Bilge pump and switch. Our 88 Sabre with CB, has a non functioning automatic switch inherited from the PO. Currently I have to use the manual function on the 3-way switch on the control panel to turn on the bilge pump an older Rule 1500 .
There is no check valve on the pump and after draining the bilge a significant amount flows back into the bilge, so we're never really dry.
My question is, will a new switch constantly turn on and off unless we install a check valve or can they be adjusted to live in a few inches of water and automatically turn on when needed. ie after a few more inch's of water collects.
Thanks for any recommendations and advice.
Mike
s/v Ladylike

 

[Rocket1]

Shortly after taking possession of our 2000 Hunter 340, the existing Rule float switch crapped out. Given the poor track record of the newer Rule switches, I opted for a Johnson switch (34-1900). The PO had installed a check valve in the discharge line, most likely for the same reasons that you describe. I have had no issues with the current setup for almost two years, and the pump get the bilge down to about 1/2" of water. YMMV.

 

[MSter]

Bob,
Thanks for the info, looks like a good choice. I'm going to add a check valve as well. I had only looked at the Rule switch's and couldn't see them working for me.
MSter

 

[Rocket1]

MSter-

No problem. FWIW, the old style Rule switches were a mercury switch that lasted pretty much forever. Of course, at some point everyone got all worked up about the mercury content so they changed their design to a mechanical style activation. Unfortunately, the new style is lucky to last a year. The Johnson switch is a sealed electro-mechanical type, and has reviewed very well, though it does cost a bit more. For the peace of mind, a few extra bucks was well worth it. Most will advise against a check valve, but I know several folks that utilize them (including myself), and no reports of any issues at this point. I got my switch at WM, though I'm sure you can get it online as well.

Cheers!

 

[MSter]

Thanks again. the fact it comes on at 2" and goes off at 3/4" seems to make sense for my application. And the check valve should help avoid constant on-off cycling as well.
MSter

 

[DannyS]

There's been much discussion about check valves in the bilge pump discharge line here and, while many people use them, it seems generally they are a no-no. They can get clogged and then your bilge pump will no longer be pushing water out of the boat. As for the pump cycling because of the backwash, set the switch just higher than the level of the amount of backwash water.

 

[Steve Dion]

I would suggest that you check out the Wema or Ultra junior switch

http://www.wemausa.com/switches/bilge_pump_switches_alarms.shtml

No on the check valve! Just slows down the flow of water and could help block the flow when you need it most (if anything gets caught in the line).

 

[Dalliance]

No, no, no on the check valve. Don't put something that can become an obstruction in your bilge pump discharge line. Ditto on DannyS' suggestion to just put the switch high enough that the backwash does not cycle the pump back on.
I would add one more suggestion - A bilge pump on an automatic switch can potentially mask a minor problem until it becomes a bigger problem. Consider installing a bilge pump counter to record bilge pump cycles. I have one and it has alerted me a couple times that something was not right.

 

[sailaway78]

No to the check valve

This is just something else to worry about. The more parts you have, the more things will break. You can only stop a small amount of water from coming back from the hose anyway, and the pump cannot get the bilge dry, so whats the use of a check valve. JMHO Also along the same lines, I believe the electronic switches, which sense water, to be much better, and live much longer than the float type. No matter the brand of float. There are a couple to choose from. Primary difference here is no moving parts, but longevity seems to be much, much better.

 

[Benny17441]

Just raising the switch may not correct a constant recycling condition; it may just continue at a higher water level. The amount of water flowback is a function of the diameter of the line and the length of the run. If the amount of water flowing back is enough to trigger the switch to turn the pump on then repositioning cannot be of help. Although the use of check valves in the discharge line is discouraged it may be a necessary evil in some installations. Did not get the impression the h340 is suffering from that and quite don't get what difference it may make between having 1/2" or 2" of water in the relatively deep bilge. If not necessary a check valve is just another thing to worry about.

 

[MSter]

Thanks for the ideas on check valves and switch's. On our boat the deepest part of the bilge is approx 15 feet + / - to the transom outlet with 1 1/8" hose and it's uphill from the bilge pump to the outlet. Seems like a lot of water flows back. I think I'll first try a new switch alone with the high low set points and see how it works. I see, as well that Whale has a version which continues to pump for 30 seconds after the low water set point is triggered. That could be interesting.
Mike

 

[NotCook]

Another consideration with a check valve is that if you are in an area that freezes in the winter, you could end up with water trapped by the check valve, which then freezes and breaks the line or valve.you would need to winterize the bilge line during winter layup.

 

[Dalliance]

Have you looked at re-routing the discharge hose to reduce the quantity of back flow? Either by creating a high point mid-way to the transom or by moving the discharge from the transom to up near the toe rail closer to the pump.

 

[alexco38]

Went different route to solve the problem.

Installed PSS seal, plug all leaks no matter how small to maintain a bone dry bilge.

Took a lot of effort but the bildge has been dry since 2007.