Sump pump level switch

**Andymadd** · 19-03-2025, 09:13 AM

Hi

When I built my filter pit I made the sump too small, this limits the size of sump pump I can fit in it. The normal dirty water pumps all seem to have the ball type float switch and I just don't have the room.

The pump I currently use has an enclosed float that works well but its not a dirty water pump and bits tend to block the impeller. So I am looking for a new kind of level sensor that will fire up the pump when needed then I can just buy a dirty water pump.

Ideas please, I have been internet searching and found nothing suitable yet.

Andy

**Manky Sanke** · 19-03-2025, 06:00 PM

Can you fit an ordinary float switch like this one? The lead to the float can be clipped to the wall close to the float itself to limit the difference between the switch on and off levels, If you can, I'll post a diagram of how to wire it to the pump if you you need it.

Float switch.jpg

**Andymadd** · 19-03-2025, 06:10 PM

No I cant get that in, I have a pump with an attached float just like that and its a solids handling pump so perfect but the float jams on the side of the sump, not enough room to free float.

**Alburglar** · 19-03-2025, 06:26 PM

https://www.ebay.co.uk/itm/186938147...mis&media=COPY

**Manky Sanke** · 19-03-2025, 06:48 PM

Tough one - a solution will be possible using switches like the ones posted above but may not be simple or cheap!!

I used to design water parameter control equipment and used a range of level control switches that could fit in confined places. However, they all had very light duty contacts so could only control electronic circuits or motors and pumps via electronic circuitry which switched high power relays that, in turn, could switch mains voltages and currents. So this may be a complicated solution.

Your current float switch will be attached to the pump so it will start off being close to the wall and therefore unsuitable for a confined space. Could you think again whether a float switch could be clipped to a wall above the pump where it will have more space otherwise it may be simpler and cheaper to build a larger chamber.

**Andymadd** · 19-03-2025, 07:05 PM

Yes I am thinking about smashing out the old sump and putting in a bigger one, then any pump will work. Low current switches and relay circuits is just a step too far, simple and bulletproof is what's needed here.

**Manky Sanke** · 19-03-2025, 07:15 PM

Yep, having spent most of my life designing smart electronics, the simplest solution is usually the best.

**noo** · 27-03-2025, 03:24 AM

What about a 12 volt DC boat bilge pump run off a transformer (to provide 12 volt DC current).

Bilge pumps are very compact, have reasonable head lift and the automatic bilge pump types have inbuilt float switches.

I'm using a 12 volt DC bilge pump for extended electrical outages.

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