Identify what the checker actually calculates
Freeview describes its detailed checker as a predictive database for likely service availability. Its multiplex tables provide Served and Marginal reception predictions for transmitters expected to be usable at the address. These are planning results, not a live measurement taken through the socket behind your television. A green prediction does not establish that the home’s aerial installation is intact.
Compare the relevant group of services
The detailed view separates multiplexes, which carry groups of channels. A prediction for one group should not be copied onto every channel from the transmitter. Record which services are missing and the relevant row in the checker. This gives a more precise question than treating the entire address as either completely covered or entirely outside reception.
Read marginal reception honestly
The checker explains that an amber result can mean a usable signal with periodic interference risk. That is different from a promise of uninterrupted viewing or proof that a television is defective. When planning equipment changes, compare the published prediction with what happens at the actual address and, where necessary, ask a qualified installer about the local installation.
Use the result before spending money
Freeview advises checking the reception prediction before buying equipment. If a result suggests a service is unavailable from the selected transmitter, a more expensive receiver does not automatically create that broadcast coverage. Conversely, if reception should be available, use the diagnostic and installation checks rather than assuming a prediction has already ruled out every local fault.
Questions, answered
Does a green checker result test my aerial cable?
No. It is a reception prediction.
Can different multiplexes have different predictions?
Yes. The detailed checker reports them separately.