Every Sunday, Neal A. DiNapoli III typically delivered groceries to his grandparents at their apartment at Felicity Tower in Bloomfield, court documents state.

But when DiNapoli and his fiancé knocked on his grandparents’ door in the afternoon of Dec. 13, 2015, there was no answer and they sensed a blistering heat coming from the apartment, court documents state.

They forced their way inside and found the motionless bodies of Neal T. DiNapoli Sr. and Immaculate DiNapoli, court documents state. DiNapoli began CPR on his grandmother and saved her life, but his grandfather ultimately died, court documents state.

Now the DiNapoli family is suing the owner of Felicity Tower and the management company at the building, claiming a defective heating/cooling system filled the apartment with “extreme heat” and ultimately killed 82-year-old Neal T. DiNapoli Sr., according to the lawsuit filed on April 21 in Essex County Superior Court.

The lawsuit states Neal T. DiNapoli Sr. was “cooked alive” and Immaculate DiNapoli, 77, was seriously and permanently injured. Emergency medical personnel determined Neal T. DiNapoli Sr.’s body temperature was about 108 degrees, court documents state.

On Tuesday, Superior Court Judge Thomas R. Vena directed the defendants to attend a June 8 hearing in the matter.

At that hearing, the defendants must explain why an order should not be issued to allow the DiNapolis to inspect Felicity Tower and, if dangerous conditions are found, to force the defendants to make immediate repairs, according to the judge’s order.

The lawsuit identifies the owner of the roughly 147-unit building on Llewellyn Avenue by various names, including Bloomfield Senior Housing Corporation, and the management company is identified as R.P. Marzulli Co., Inc., among other similar names. Thirty units are Section 8, assisted living units for senior citizens, the lawsuit states.

The plaintiffs are Neal A. DiNapoli III, Immaculate DiNapoli and her son, Neal DiNapoli Jr., who also is the administrator of his father’s estate.

In a statement on Thursday, Wayne-based Scura, Wigfield, Heyer & Stevens, LLP, the law firm representing the DiNapolis in the lawsuit, said:

“The heating/cooling system in this senior citizen complex is recklessly configured putting this low income, senior citizen population at great risk.   In order to cut corners on cost, the owner and management company are responsible for the death of Neal DiNapoli Sr. and near death of his wife. Our firm is hopeful that by bringing this situation to light other senior citizens will be protected, and the great harms and losses suffered by our clients will be addressed.”

When contacted by phone on Thursday at the Marzulli headquarters in Bloomfield, a man who only identified himself as Dan said he was a Marzulli representative and declined to comment.

“We have no comment on any pending litigation,” said the man, who declined to provide his full name.

Following the incident, the DiNapolis’ attorneys conducted a preliminary investigation of the apartment with an HVAC professional, according to the lawsuit.

That investigation revealed the heating/cooling system in the apartment has no temperature control valve and can only run one temperature of water at a time, the lawsuit states. The system cannot self-determine if it is expelling hot air or cool air or automatically shut off if it is getting too hot or cold in the apartment, according to the DiNapolis’ attorneys.

Since the system does not have separate lines for hot and cold water, the building management fills the coil with either hot or cold water, depending on the time of the year, the lawsuit states.

In other words, when the incident occurred in December, only hot water was running through the line, the lawsuit states. Hot water also would constantly run in the coil, creating perpetual residual hot air even when the system is turned off, the lawsuit states.

Given the unseasonably warm temperatures outside around the time of the incident, Neal T. DiNapoli Sr. and Immaculate DiNapoli set their thermostat to cool the apartment, according to the DiNapolis’ attorney’s.

But the thermostat could not determine it was in hot water mode, and continually ran the blower at the highest flow rate, the lawsuit states.

“Consequently, the heating/cooling system will try to reach a cool set point that it will never obtain because only extreme hot air is pumping from the unit,” according to the lawsuit.

“The dangerous heating/cooling system defectively functioned in this way, which resulted in the extreme heat event in the DiNapoli apartment unit.”