Sump Pump failure to prevent Basement Flooding often caused by Clogging!

Reports of failing sump pump accompanied news coverage of flooding caused by Storm Ciara, the latest extreme rainfall event to hit the British Isles. In some regions, between 40 and 80mm of rain fell in 24 hours with the highest levels reaching nearly 180mm (DEFRA, Feb 2020). The latest government estimate is that 500 properties were impacted, some of which were flooded in previous years, and in the days following, there were nearly 100 flood warnings still in place.

Property owners who did have a basement pump installed will be completely devastated that it failed to function as required. In some cases, especially in known flooding ‘black spots’, the cost of damage refurbishment may no longer be covered by the owner’s insurance policy. Many owners point to an inadequate flood defence policy by the Environment Agency which leaves their properties at constant risk of repeat flood damage during the increasing number of extreme rainfall events across the UK.

Property owners should be able to rely on a sump pump system

It’s therefore vital that property owners should be able to rely on a sump pump system that does not fail when its most needed to remove the excess water. Keeping a properly functioning basement pump requires periodic maintenance and service checks to ensure the unit does not become clogged and prevent vital components from fully functioning.

One of the most common reasons for a pump to fail is a float switch clogged by mud and dirt that is stuck in either the “on” or “off” position. While a sump pump that is unable to turn on in the first place may simply not be noticed by an owner until an extreme rainfall event occurs, a pump which runs nonstop will soon burn out and also fail when most needed. A service check would have immediately picked up the problem.

Another type of clogging can often the result of a build up of oxidising iron ochre – a thick, soft, rust-coloured deposit that oozes from the system caused by bacteria. Although there are no known health affects from iron ochre, it’s presence is foul smelling, causes stains and will clog drainage systems.

Sump pump clogging may be present from the day it was incorrectly installed

Unfortunately, the susceptibility of a sump pump clogging may be present from the day it was installed if it was incorrectly situated within a “mud zone”. An entire sump pump system will often be installed as part of a drainage system around the basement perimeter, which then collects water from the walls and floor before flooding into the basement area itself. Firstly, there can be instances where wide-open gaps in drains that run evenly at ground level may collect debris from the basement floor, which can then clog a drain or sump pump system.

Secondly, there are also other types of drains that can be installed directly in the mud beneath a basement floor in a “mud zone” area. Over time, mud will begin to seep into and clog the drainage system. Unfortunately, once clogged, these types of systems may be impossible to access for a service repair without taking up significant areas of the basement floor.


Sump pump failure is preventable!
A service contract check is essential!
TEL  01634 215192