Inspection Access

Access

I have been unable to gain access for an inspection of my rental property for over two and a half years. The tenant and her children had continuous passing around of covid for the last two years and the 7 appointments made over the last two months have been cancelled giving several reasons from health issues to work etc.
I am rather concerned as she let the gas fitter in through the kitchen door to service the boiler and would not allow him anywhere in the house to check the radiators. She has not been the best of housekeeper and I am concerned that there may be repairs issues that could get worse.
Is there any legal means by which I can get access to the property without having to resort to Section 8 (she is in arrears but has kept up with the agreement of rent + an agreed amount towards arrears) or Section 21 which would really mean a lengthy process through the Courts?

Thank you