Fireman Jay Brenton Liptrot, 43, from Prestatyn, Denbighshire, was due to enter not guilty pleas at a hearing at Mold Crown Court on Monday.
But a live TV link to a judge sitting in court in Swansea failed to work.
Lee-Ann Shiers, 20, her partner Liam Timbrell, 23, their son, and her nephew and niece died in the fire in 2012.
After the technical problems, the plea and case management hearing took place in a telephone conference room with the defendant, barristers, solicitors and court officials sitting in a small side room.
Defending barrister Gordon Cole QC indicated that his client would be pleading not guilty to all charges but the judge agreed that it would not be appropriate to do so over the telephone.
Judge Keith Thomas made various directions in advance of the trial, which will be held at Caernarfon Crown Court, starting on 16 November. Mr Liptrot was bailed pending that hearing.
He indicated not guilty pleas to all five charges of manslaughter, alleged to have occurred between 18 October and 6 November, 2012.
Melanie Smith has already been jailed for at least 30 years for five counts of murder after starting the fire in a row over a shared hallway.
The owner of a house in which five people died in an arson attack will go on trial charged with their manslaughter in November.