I have a municipal water-powered sump pump that acts as a backup in the case of a power outage. However, the valve (a black plastic arm extending from the water line that holds a string with a float, feeding a garden hose that goes down to the pump housing) appears damaged and leaks a lot, so I'd like to replace it. I've been unable to find something that looks similar. All other float valves I've been able to find are intended for filling tanks, where a high water level shuts off the water flow, whereas I want the inverse behavior: maximum flow when the water level rises. Can I turn one of those upside-down or something that would give me the desired behavior?

I'd appreciate any suggestions for suitable float valve configurations I could use. In case it matters, I'm in Michigan, USA.

Edit: The water-powered sump pump looks very similar to this K2 Pumps model, and the part of interest is labelled "pump starting valve" at the bottom of page 6 of their manual.

3 Answers 3


You should buy the appropriate part from the maker of your backup pump rather than try to adapt something not designed for it. Better yet, replace the whole thing with a new and better one. They are not expensive, and this is not an area to skimp.

Take a robust approach to installing it. Garden hose and string should not be part of a backup system for critical flood prevention. How often will this see action? Maybe once in 20 years? How often do you test it? Ever? It's already leaking ... that should never happen.

I don't know much about your installation but I'm willing to guess it's a little sketchy? Beware: A water-powered sump pump that is poorly installed and fails can have a disastrous effect: In addition to the flood water entering the basement, the failed pump can add the full force of the municipal water supply, like having a garden hose turned on full blast filling the basement -- right when you need it least.

My recommendation is to buy a new pump and either have it professionally installed or read the instructions carefully, watch MANY tutorials on youtube, and try to outperform them all in your work.

  • The part I found is $25 + $15 for shipping. A new, updated water-powered backup pump starts around $150, and better quality versions (which include an integrated float valve) around $225. Since robustness is essential (as you've pointed out), I'm going to go this route. Thanks for the advice!
    – Paul Price
    Mar 11, 2023 at 14:53

I like pumpspy with a deep cycle marine battery for power outage scenarios. Garden hose and string sounds unideal especially if you ever go away.

~$2000 allows you to just keep your standard pump plugged in without fear for power outage or any additional hookups or plumbing.

The downside is the deep cycle marine battery that need occasional replacement. I have two pumps activated by the hydrocheck hi/lo electronic floats (allows precise activation and deactivation).

One will only ever activate if the water hits the absolute top - indicates either the primary failed or the primary is unable to keep up with inflow. I was thinking of adding a 3rd pump that would swap even/odd days with the primary via an electric timer.


I contacted the manufacturer of a model that looks very similar to what I have, and they pointed me to this control valve.

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