Across
5a
Institution in blender? (7,7)
See 1
Some distance into Palmyra, Fallujah the other way (4)
See 21 Down
Seller with express service (6)
A little water I required in relaxation before work (8)
I haven't cracked this one yet — but Fifteensquared have:
I (from surface) inside R AND R=R&R=rest & relaxation; before OP (opus, “work”)
Registered arrival listening to the hubbub in Prague, say? (7,2)
A knob in drawer, currently? (5)
See 3 Down
A quote recalled by the way, passionless (9)
I haven't cracked this one yet — but Fifteensquared have:
A (from surface), plus: CITE=”quote” reversed/”recalled” after PATH=”way”
Appear just if seamer proves unreliable (4,4)
Aussie crook having fed prisoner, one's stuffed (6)
See 21 Down
Vessel drained, did you say? (4)
Collectively, nothing more to say? (3,4)
Currency banked by my lord (7)
Down
Upside-down person in bondage secured by that woman's brace (7)
I haven't cracked this one yet — but Fifteensquared have:
definition: as in a ‘bracing’ or ‘refreshing’ breeze reversal (“Upside-down”) of: SERF=”person in bondage” inside HER=”that woman’s”
17a
Concern after extreme anxiety voiced, in need of a safe landing place (5,5)
TV as a gift, delivered (3,4)
Peak overlooked in country somewhere in SW Europe (6)
I haven't cracked this one yet — but Fifteensquared have:
[L]-IBERIA=”country” with its first letter/”Peak” removed
Villa, say: team in conference having missed the first half (9)
Broadcast indicated might in giant chestnut tree (7)
Ogre, I repeated, messed with Peg in children's rhyme (7,6)
I haven't cracked this one yet — but Fifteensquared have:
anagram/”messed” of (Ogre I Ogre I peg)*
Curve about me, soft ultimately, French food (9)
I haven't cracked this one yet — but Fifteensquared have:
CAMBER=”Curve” (of e.g. a road), around ME (from surface) + last/ultimate letter of [sof]-T
Calm and collected announcement of educational establishment in 'ackney? (3-4)
Fifth shirt and jumper, say? (3,4)
26a
Pop star I bet OK playing end of tune: note in second track and first following every piece here in song (1,2,4,2,2,6,3,7)
WWI nurse lifting some from hell, evacuated (6)
Bloomer in this setter short of a failing? (5)
I haven't cracked this one yet — but Fifteensquared have:
definition: the name of a flowering plant i.e. a bloomer anagram/”failing” of (in Paul)*, minus “a” Paul is “this [crossword’s] setter”
Type letters or click words in the clue