bbzcat Anderson

I let a property and last year the boiler broke down and had to be replaced as repairing it was too costly given the age. I have read elsewhere on this forum that for self -assessment the costs of a new boiler like this should be put down as part of 'repairs and maintenance' and not as 'replacement'. However, if I do that on the online form I am being given a warning that the 'repair/maintenance' costs are too high for the property income. Please can you advise as to what the right way forward is?