I have a Worcester Highflow 400 which is only 3 years old and it has
suddenly developed a leak. It seems to be dripping below the "water to
water heat exchanger" towards the aft end of it away from the 2
manifolds firrted on the front face of it.

Struggling at the moment to get someone out to repair it so getting
the feeling that I will be doing it.

Has anyone on here replaced one, how easy, how long to do it and is it
a common fault?

Are these also called the plate exchanger?

cheers