Estella explicitly says that she has "no heart" in chapter 29:

"You must know," said Estella, condescending to me as a brilliant and beautiful woman might, "that I have no heart—if that has anything to do with my memory."

Pip, of course, does not believe her, because he is still convinced that Miss Havisham has "destined" him for Estella and Estella for him. Later, in chapter 34, on a page subtitled "My Love Unintelligible to Estella," she says,

When you say you love me, I know what you mean, as a form of words; but nothing more. You address nothing in my breast, you touch nothing there. I don't care for what you say at all. I have tried to warn you of this; now, have I not?

Estella has been warning Pip from the very beginning of their relationship that she is cold and manipulative (while at the same time tempting him on, as she has been raised to do by Miss Havisham). Pip's refusal to accept reality is Dickens's sadly satiric take on "love is blind."

The ending of Great Expectations, in which the chastened and wiser Estella and Pip find happiness, has perhaps been justly criticized for sentimentality. It is probably much more likely that anyone programmed from childhood as Estella was will never change.

It is in Chapter 29 that Estella tells Pip that she has no heart. We see in this Chapter that Pip's feelings of seeing Estella and being in Satis House again are a strange mixture of pain and pleasure, for whilst she is flirtatious, she is also coldly distant, and her warning to Pip of her lack of heart is a direct contrast to Pip's hopes of being the romantic hero, rescuing Estella and breathing new life into Satis House.

It is also worth examining other events that jarr against Pip's hopes - the presence of Orlick as the doorman and in particular Miss Havisham's urgings for Pip to love Estella in a way that makes it sound like a curse rather than a blessing. All serve to undercut Pip's youthful and naive expectations and desires concerning his love for Estella.