I have a electrical pump for my fish pond that I use to drain the water every so often to clean it out very well. Something has chewed through a portion of the wire, so the pump is not working at all at the moment.

My question is two fold

  1. How can I repair the connection to make it water proof, if in fact the cord does get into the water, which often times happens
  2. If possible, how can I make the cord longer (and remain waterproof)?

This is what the end of the cord looks like end

Image of pump and break break pump

  • 1
    How about a few pictures so we can see what you see.
    – JACK
    Commented Apr 16, 2022 at 22:52
  • When you state cord what are we talking about? Making a splice as referenced below would be a code violation to cordage, we need to know what we are recommending.
    – Ed Beal
    Commented Apr 16, 2022 at 22:57
  • @EdBeal - edited OP to show image Commented Apr 16, 2022 at 23:02
  • 1
    This is where code gets tricky, to make this cordage longer you need a section of cordage that the outer covering can be stripped and the cloth/fiber restraints tied into the old cord, water tight connections then a over all water tight covering over the splice. At my last job many times I did not mess with cordage under 10 awg , but regularly did repair larger and much larger sizes that were OSHA / MSHA legal , when type w cordage is 20$ a foot for a large peace of equipment you repair it and the requirements are that it has to meet the strength, water/ sunlight resistance to be approved.
    – Ed Beal
    Commented Apr 16, 2022 at 23:15
  • @EdBeal - added images to show actual break and pump image....yikes, sounds like this is dangling on some tough spots for sure. Hmmm...by chance do you recognize this type/style pump and can provide a link to similar one and i'll just purchase a new one? Commented Apr 16, 2022 at 23:25

2 Answers 2


You seem to be comfortable enough to want to repair the cord instead of just pitching the pump & buying a new one, so I'd suggest that you completely replace the cord.

Open the pump up, detach the existing cord from the pump entirely, then replace it with a longer length of equivalent cordage all the way from inside the pump to the plug.

You'll have to read the labeling on the cord to know what type of cord and also what AWG it is. You'll need to use the same type and the same or larger AWG. For example if the current cord is 14 AWG, you'll need to use 14 AWG cord, but you could also use 12 AWG (which is a thicker actual wire), so long as the new cordage will fit through the water-tight seal on the pump.

You'll also need a water-tight, outdoor rated plug to put on the other end.

When you're doing this, you can buy as many feet of cord as you want so that you've got one unbroken run from pump to plug.

  • I absolutely would not open any submersible waterproof pump to replace the cord. Many years ago, these sump pump/pond pumps did have removable covers but now almost all small home submersible pumps are sealed. For safety, it is best to replace the pump because the cover is broken and the wire has been cut. If I did repair and extend the cord length with the appropriate outside wire, I would use several layers of waterproof heat shrink tubing on both the wire connections and a final tube covering of all the connections. Commented Apr 19, 2022 at 22:06
  • OP - can you provide a picture of where the cord enters the pump. That pump looks like a sealed unit, NOT designed to be open and have the cord replaced. Commented Apr 19, 2022 at 22:09

Look for water proof well pump connectors, They are heat shrink tubing with stuff to keep water out.

Probably other types of water proof connectors also.

To make longer, just need to use longer wire of the same type. Should try to keep a single connection, than add a section to the centre. The fewer connections usually better, but can be done if needed. enter image description here

Seeing the pictures, it will probably be better just to get a new replacement cord, no splices.

Any hardware type store should have generic replacement cords for power tools.

  • the current plug is one that has the plastic around the outside protecting the wiring, and one side goes to the pump and the other side to the plug. Do the local box stores have a longer cord that has the plug side on it? Commented Apr 16, 2022 at 22:56
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    The 3 wire water proof splices are not for cordage but connections in a well or buried location as allowed by code splicing. Above ground cordage the repair has to maintain the integrity of the original covering / fiber stress reliefs in the cord to prevent stress on the wires.
    – Ed Beal
    Commented Apr 16, 2022 at 23:02
  • 1
    what about putting a male repair end on the cord where it was cut and using an extension cord and a water tight cord lock? Commented Apr 17, 2022 at 5:50
  • The op stated that this connection was likely to get wet often times so probably not a good idea to shorten the cord.
    – Ed Beal
    Commented Apr 17, 2022 at 15:27

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