[In the UK] I need to replace the condensate pump in my basement (for pumping condensate from the boiler), and the current one is simply wired up to a standard 13A plug, but reading the instructions on the new pump (a direct replacement, same make+model), it specifically says not to do this:

"The unit should be connected to a fully earthed electrical supply. All wiring must conform to BS7671, 1992 requirements for electrical installations. The SANICONDENS® Eco/Basic requires a 220/240V single phase AC 50 Hz supply (UK specification). Do not connect SANICONDENS® Eco/Basic to a conventional plug and socket. It must be wired into a fused, unswitched, fixed wiring connector fitted with a 5 amp fuse. SANICONDENS® Eco/Basic has an Earth wire.

The wires in the mains lead are coloured in accordance with the following code:

  • Brown – Live
  • Blue – Neutral
  • Green/Yellow – Earth"

[Cue stupid question] Why can't I use a normal wall plug but with a 5A fuse? What benefit is there for the connection to be unswitched for what is a fairly simple pump? Obviously I want things to be in reg's, so just trying to work out if I need to call out an electrician, just don't want to be embarrassed if he wires up a plug :)

Thanks all for any help

1 Answer 1


I can't speak to code directly, but generally things like pumps are placed on non-switched circuits to prevent someone from accidentally turning off the pump and then flooding the house.

Imagine a scenario where someone is trying to figure out what the switch does because they can't/won't follow the cable. They flip the switch a few times and nothing happens. There's now a good chance that the switch is in the off position because a) if they're too lazy to follow the cable then it's a safe bet that they are too lazy to remember or care about which position is on, and b) there is no external indication that the switch is off because the pump only runs when it's full of water.

  • Which is pretty much the same reason it shouldn't be wired with a plug and a socket. Commented Apr 21, 2015 at 4:34
  • Thanks longneck, makes sense. In my case it's very unlikely that the socket it is connected to would be used for any other purpose, but I will add an audible alarm to this setup so that it'll warn me if the water in the task is too high.
    – JonoW
    Commented Apr 21, 2015 at 9:47

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