Issue notice to the seller to clear all outstanding dues of electricity charges. In default file a recovery suit against the seller under summary proceedings.

You can send the notice to the said owner and recover the same from him. He needs to pay. You can also file criminal complaint of cheating as he stated that he had paid all dues

Summary proceedings is a process of speedy disposal of suit where plaintiff seeks only to recover a debt with or without interest under order 37 rule 2 of CPC. 

1. Well, your buyer is not bound to take the liability which you should have cleared at the time of your purchase.

2. Now since you have made the mistake , to correct it is your sole responsibility unless the buyer is ready to take it.

3. Since your buyer is not ready take the liability you will have to adjust this 5L amount though you have the option of recovering it from your seller.

4. T recover the amount you can file civil suit for recovery of money.

A legal notice can be given to the previous owner and an application must he given to the executive engineer of the company or the designated officer in that company who would pass an order.

Regards 

Liability of payment is upon previous owner 

there must be indemnity clause in your contract wherein you are indemnified in case any claims are made 

issue legal notice to seller to pay electricity arrears 

Call upon seller to pay dues as mentioned herein above 

Summary suit has to be filed by you against seller on basis of your written contract 

You should serve a legal notice through advocate to the previous owner for clearing previous dues of electricity before selling of the house. 

He is liable to clear previous dues due to indemnity clause of sale deed.

If he refuse to clear dues file recovery suit against him.

You need to pay the bill and give a legal notice to the first owner to pay the bill if he fails you need to file a suit to recover the amount and the interest. 

See you have to pay amount to stop interest charges. 

Summary suit is kind of recovery suit decided summarily by the court it is fast and takes less time then normal civil suit filed before the civil court. 

Dear Sir,

The following information may kindly be read;

A consumer cannot be compelled
by the State Electricity Board to clear the dues of the
previous owner of the premises he has purchased in an auction
unless there is a statutory requirement or prior agreement to
the effect, the Supreme Court has held.

"In the absence of any statutory rules authorizing a
demand for the dues of the previous occupant, an auction
purchaser seeking supply of electrical energy by way of a
fresh connection, cannot be called upon to clear the pre-sale
arrears, as a condition precedent for granting fresh
connection," a Bench of Justices R V Raveendran and H L
Gokhale said in a judgement.

The apex court passed the judgement while dismissing
the plea of the Haryana State Electricity Board challenging a
Punjab and Haryana High Court ruling that M/s Hanuman Rice
Mills, an auction purchaser was not liable to clear the dues
of Rs.2,39 lakh owed by the previous owner M/s Durga Rice
Mills.

M/s Durga Rice Mills at a cost of Rs.15,25,000 on December 14,
1990 in an auction conducted by the Haryana Financial
Corporation for recovery of its dues .

The State Electricity Board granted a fresh
electricity supply to the Mill, but four years later issued a
notice on January 16, 1995 demanding Rs 2,39,251 towards
arrears of electricity charges due by the previous owner.

After the new Mill owner refused to pay the dues, the Board
disconnected the power supply.

Since the agreement is clear on the aspect of clearing dues, you have every right to claim the arrears from the seller. issue a legal notice through an advocate and file a suit for recovery against the seller. 

This is my response to you:

1. First send legal notice to first owner;

2. Then you may have to approach the court and file a suit against him;

3. As long as you have rightfully paid your dues, you have nothing to worry;

4. Consult a local lawyer and take steps.

You verify and confirm the pendency of the electricity consumption bill payment, ask the previous owner about it  to pay the same or else you may have to pay it on his behalf and recover the same from the previous  owner by due process of law.

You may have to confirm the payment dues to the company and pay it to avoid accumulation of interest amount anymore.

If you keep getting confused over it then the interest amount will become more larger.

You can consult a lawyer ion the local and proceed with the summary proceedings case to recover the same from the previous owner after paying it