If they are still complaining about the stove, make an appointment to go over and see what is going on. That
1) allows you to visually look over the interior for damage;
2) verify for yourself that the stove is working properly, and ensure that they are using it properly or teach them how to use it, if they are not.
I would be very surprised if a working stove were not legally required, and even though you have two verifications that it is working, f they still say it is not, you will have direct proof that you verified its condition yourself, and provided them with instructions on proper use.
1) allows you to visually look over the interior for damage;
2) verify for yourself that the stove is working properly, and ensure that they are using it properly or teach them how to use it, if they are not.
I would be very surprised if a working stove were not legally required, and even though you have two verifications that it is working, f they still say it is not, you will have direct proof that you verified its condition yourself, and provided them with instructions on proper use.