Basements and cellars
A sump and pump sit in the cellar floor and the power was off. What flood path is that pump there for, and what has not been run?
The sump and pump are there to lift water that collects in the cellar, and nothing was run because the power was off. The survey can record the sump in the floor, the pump and the dead supply. It has not seen the pump start, watched a discharge, or proved where water would go if the cellar took in water. No flood was staged as a test. The equipment explains the path it was fitted for. The visit did not demonstrate that path.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What is the fuller explanation?
Cellar sumps collect water that reaches the floor, from the ground around the walls or from a drain that backs up, and the pump lifts it to a discharge. Without power, that chain stops at the hardware. A dry sump on the day does not show the pump would start, that the non-return valve holds, or that the outlet is not blocked. The survey records a pump that was not operated. It does not record a successful test.
Ask an electrician or the person who maintains the pump to see it run once the supply is on, and to say where the discharge goes. That is outside the home survey. Tell the solicitor the power was off, so a seller remark that the pump works is unverified. Do not describe the cellar as flood-tested. The path the pump is there for was identified. It was not watched.
What should you ask your surveyor?
- What is the sump there to collect, as far as the installation shows?
- Was the pump run at all, given the power was off?
- Did you see where a discharge pipe actually leads?
What are the typical next steps?
- Describe the sump as a collection point that was not operated.
- Do not write the unpowered pump as a passed flood test.
- Have the pump run on a live supply before you rely on it.
Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.
Also asked about this
If the sump was empty, is the pump unnecessary?
An empty sump means water was not standing in it on the day. It does not mean the cellar never takes water, and it does not mean the pump is spare. The survey still has not run the pump, so necessity and performance are both undecided.
Does an alarm float in the sump count as running the pump?
No. A float or alarm is another piece of hardware in the sump. Unless it was tested, and unless the pump was seen to start, the survey has only recorded fittings. The flood path was not demonstrated on the day.