Tenant's Heavy Wardrobes in UNfurnished property

Our new tenant moved in 2 months ago. 2 weeks ago she complained that some cracks were appearing in some upstairs ceilings and bottom of stairs ceiling was giving slightly. And her wardrobe door wouldn't close properly any more. She wondered if the house was subsiding!

Tenant was friendly when we visited to inspect, but it turns out that she has installed 2 whole wall-lengths of flat-pack furniture which she volunteered was very heavy furniture.

We have paid our friendly builder to inspect and he says nothing wrong with house; but when tenant moves out we should get someone to inspect the floorboards before the next tenant as furniture is a bit overloaded.

I have since realised that the wardrobes on one side completely cover over the gas central heating radiator. Tenant has previously said the house is very warm.

There is nothing in the Tenancy Agreement about furniture introduced (only about if property is Furnished you must seek approval before bringing in other furniture).

Do you think I am in my rights to ask tenant to remove the wardrobes?