Any ideas on what this part is??

[Racheal1256]

Had a plumber in whilst I was on holiday to fix a leaking condensate pipe on system boiler but have noticed he’s also fitted something on my unvented cylinder on the return secondary circuit. I’ve circled the part on the two pics. Anybody got any idea of what this is?
Plumber not returning any of my calls hence asking on here

I did mention that as per manufacturer’s instructions a non return valve was needed between cylinder and pump but I’m sure this can’t be it??

Thanks for any help

 

[cjg]

its a non return valve thats been fitted

 

[Racheal1256]

its a non return valve thats been fitted

Thank you. Is it fitted in the correct place? I was told it should be below the pump where my squiggle on the pic is?

 

[ShaunCorbs]

No it’s fitted correctly anywhere on that leg / pipe is fine