No others can be responsible for the property other than the owner if one knows basic legal matters.

If the landlord have consulted a lawyer to prepare the TA instead of agent. Penny wise pound foolish if something like TS case. Lawyer charged 1 month rental as legal fee excluding disbursrment for TA which many landlords wont want to pay as they also need to pay the agent fees. That would be only 10 months rental collection for a year tenancy.

How you know it's been 3 months?
If not mistaken after bill is out user allow to have 30 days to clear it.
Btw below is from TNB site:
Some owners are left with hefty bills after their tenants have moved out. How can owners protect their rights?
Property owners have two choices as below:

1. In the situation before a new tenant moves in, property owners could do a Change of Tenancy making the tenant fully responsible for any delinquent account. However, owners will lose the right to instruct a disconnection to TNB in the event the tenant defaults in his monthly electricity bills
2. Owners could register with myTNB and would then be able to monitor their tenant’s monthly usage and payment pattern