Radon
A radon fan is running in the cupboard and the pack has no measurement result. What level has the running fan not proved?
The running fan has not proved any radon level. It shows that a fan in the cupboard was switched on and turning. A fan is a piece of equipment. A level is a measurement, and the pack has no measurement result. The survey has not measured radon, not sampled the air, and not read a result that is not in the papers. UK radon guidance and maps are separate from this inspection. Hearing or seeing the fan is not a figure, and it is not a pass.
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?
Sumps and fans are fitted in some houses to draw air from beneath a floor. Whether this fan is doing that, whether it runs all the time, and whether the level in the rooms is acceptable are questions a measurement answers. The survey can say the unit was running and can say the pack lacked a result. It cannot invent the missing result from the noise. No result in the pack means no result to quote.
Ask the solicitor whether any radon report was supposed to be in the pack, and ask for it if the sellers say one exists. If you need a current level, that is a radon measurement arranged for the purpose, not a second look at the cupboard. Do not tell a lender the fan has cleared the house. The survey has not said that. Keep the running fan as a piece of equipment that was seen, and keep the absent result as absent.
What should you ask your surveyor?
- Did you see the fan running without recording any radon measurement?
- Is there a result in the papers you were given, or none?
- Have you left the level unproved rather than inferred from the fan?
What are the typical next steps?
- Treat the running fan as equipment, not as a radon result.
- Ask for any measurement the seller says exists.
- Arrange a radon measurement if you need a current level.
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 fan is noisy, is the level high?
Noise is not a level. A loud fan can be an old motor, a poor mounting or simply the way that unit sounds. The survey has not measured radon. The pack has no result. UK maps and a proper measurement are the routes to a level, not the sound in the cupboard.
Does switching the fan off during the visit create a result?
No. Switching it off, or leaving it on, changes whether you heard it. It does not measure radon. The survey still has no sample and no result. A fan that was stopped for a conversation is still only a fan. The level remains unproved.