Ceiling problem

[cyclopse]

Here are some images of the kitchen ceiling where the oil boiler exits the room from above. I have chipped off the old plaster to reveal this. The height of the ceiling appears to have dropped around the pipe.

Any advice most welcome.

 

[Alec_t]

Looks like there's been a persistent wet patch there at some time. Is it still damp?

 

[lostinthelight]

It may be a trick of the light but are the flue pipes the wrong way up, it looks like the collar is above the spiggot instead of the collar bellow it.
If they are the wrong way up, any liquid inside the flue can weep through the joint
litl