Purplepopple
I did say the site took some getting used to! Complicated at first, but worth persevering with.
The selection you want in this instance is the 21st: "Find words of at least seven letters made from given letters" (7 letters is just for example, see below)
The format used is "7-:*/rpoyesdif"
So, to find all words of 3 or more letters from airedale, you would enter
3-:*/airedale, i.e. change ONLY the number to the minimum number, and any (within reason) number of leteters.
The result given is
Length 3
ada aia aid ail air ala ale ali ard are dae dal dee del die ear eel eer ela eld eli era ere ida ide ire lad lar lea led lee lei lid lie rad rae rai red ree ria rid
Length 4
adar aida aide aire alae alar alda alee area ared aria arid aril arle dail dale dali dare dari deal dear deer deil dele deli dere dial dire dirl dree eale eard earl eild eire elea elia erda erie idea idee idle ilea lade laer laid lair lard lare lead lear leda leed leer leir lere liar lide lied lier lira lire raid rail rale read real rede reed reel rial ride riel rile
Length 5
adela adele adler aerie aider ailed aired aldea alder ardea aread areal arede ariel arled deare delia drail eared edile eider elder elide ideal idler irade laird lered liard raile reade redia riled
Length 6
aedile aerial dealer dearie derail laired leader leired lieder radial railed realia redeal rediae redial relaid relied
Length 7
laridae leadier radiale
Length 8
airedale