This is a pretty obscure fact, but I did manage to verify it on enough websites to satisfy me that it was worth recording (because if it's on enough websites, it's always likely to come up again).
So obscure is it that it isn't mentioned on Fireman Sam's Wikipedia page. Although if you type 'Samuel Peyton–Jones' into Wikipedia's Search field, it does redirect you to Fireman Sam.
Some of the websites on which I did manage to find corroboration are the Daily Mirror (in a list of '63 QI facts to stop you in your tracks'), the Daily Mail (in another list of 'QI facts'), and Wales Online. Note that the first two of these, as well as originating in the same source, are articles of the 'things you didn't know you didn't know' kind – which (IMHO at least) brings into question their suitability for use as sources of quiz questions. However, as I've already said: if it's on enough websites ...
According to LinkedIn, Samuel Peyton–Jones is a real–life firefighter who works on Humberside. You can either take this or leave it!
When recording things like this, I always like to include a note about where the factoid originates; for instance, on my James Bond page I note that the name of Bond's Swiss mother is mentioned a Times obituary in You Only Live Twice, the penultimate Bond novel. In the case of Fireman's surname I can find no such evidence.
Quiz setters: you have been warned!
© Haydn Thompson 2020