A part is only right if it goes back in correctly
We will happily supply parts to an in-house maintenance team, and plenty of our clients fit their own consumables. But a filter seated badly, or a fan replaced without checking the duct resistance, leaves a cupboard that looks fixed and is not.
Anything that affects airflow should be verified after fitting. Our engineers can fit and check in the same visit, anywhere in the UK, and retest the unit before it goes back into service.
If you know the make and model, tell us. If not, photograph the data plate and we will identify it.