What is this?
When a property floods — whether from a burst pipe, river flooding, or surface water — the electrical installation can be severely compromised. Water saturates cables, back boxes, junction boxes, and the consumer unit. Even after the floodwater recedes, the electrical installation is unsafe until professionally inspected and tested. Contaminated floodwater (sewage, chemicals) causes additional corrosion damage.
Common causes
- River or surface water flooding entering the property
- Major internal leak or burst pipe flooding rooms
- Sewage backup flooding the ground floor or basement
- Drain failure causing standing water in the property
- Loft tank overflow flooding down through the house
Is it dangerous?
Flooded electrics are life-threateningly dangerous. Standing floodwater may be electrically live if it is in contact with any part of the installation. Do not enter flooded rooms if the electrics are still on. Do not touch the consumer unit if it has been submerged. Call your electricity distributor (DNO) to cut the supply at the meter if you cannot safely isolate it yourself.
Can I fix it myself?
If the consumer unit is above the water level and you can reach it safely without walking through water, turn off the main switch. If the consumer unit has been submerged, do not touch it — call the DNO on 105 to cut the supply remotely or at the meter. Once the water has receded and the supply is confirmed off, you can begin drying out the property, but do not restore electrical supply without professional testing.
When to call an electrician
Call an electrician as soon as the property is safe to enter. Every circuit that has been affected by flooding must be tested before the supply is restored. This is not optional — energising flooded electrical circuits without testing can cause fires and electric shocks. The electrician will carry out a full EICR.
What will an electrician do?
Assess the extent of water damage to the entire electrical installation
Allow adequate drying time before testing (typically several days for saturated plaster and voids)
Carry out insulation resistance testing on every affected circuit
Replace all sockets, switches, junction boxes, and fittings that were submerged
Replace the consumer unit if it was submerged, including all MCBs and RCDs
Issue a full Electrical Installation Condition Report before supply restoration
Typical cost
£300 – £2000
Flood damage repair varies enormously. A full EICR is £200–£350. Replacing all ground-floor sockets and fittings can cost £500–£1,500+. Consumer unit replacement is £350–£600. Insurance typically covers flood damage.
