Small, non-structural improvement works - such as fitting a new boiler, or like for like non-structural works do not require consent under Standing Order 930 (1). There may be exceptions to this however if your property is in a conservation area or the building is listed. In such instances, you will need to contact the Conservation Office on 0161 235 6722 or email The Conservation Office.
Before you proceed with the work, it's also worth talking to your district property secretary to find out if they want a project for the work you are planning on doing.
TMCP have also provided a helpful flowchart of when consent is required for a project: Consents Flow Chart