Cracks above skirting board

[Allie16]

hi guys,
I moved into my house in may it’s a mid terrace built in 1904 I had a survey done nothing structural was picked up and the house has been damp proofed.
I’ve noticed hairline cracks in the bathroom and spare room but these have recently been replastered before I bought the house so not too concerned about those.
Today however I’ve noticed some bigger cracks directly underneath the radiator in the dining room above the skirting board. These are confined to under the radiator only but are quite deep into the wall. Is this just because of the heat off the radiator? Or something worse? The dining room is the oldest part of the house

[GALLERY=media, 102387]62D56DE1-ACCB-4EBE-8F33-5EE1A1E6FC65 by Allie16 posted 6 Jan 2019 at 4:20 PM[/GALLERY]

[GALLERY=media, 102386]7E066597-BA93-42BB-86E5-76CC7C835B2C by Allie16 posted 6 Jan 2019 at 4:20 PM[/GALLERY]


[GALLERY=media, 102385]3FB8D4E6-570D-4CF0-B7B2-1BDB486D2A10 by Allie16 posted 6 Jan 2019 at 4:20 PM[/GALLERY]

 

[^woody^]

If the cracking is even, and along several walls or a single wall, then its probably shrinkage, and that would include for localised areas behind radiators.