Question: Do the combustion chambers ever blow up because of too much heat?

Stephen Pulker answered on 14 Mar 2017:

All parts of rockets are design very cleverly to stop this from happening . . . but, yes, early in rocket development (when the design is still on-going or being tested for the first time) is it not unknown for rockets to explode . . . the reasons can be quite varied as rockets are such complicated systems and there are lots of things that could go wrong . . . I don’t know of a specific instance of an engine exploding but I am sure there is one.