Sky TV is investigating what caused a decoder to burst into flames.
The pay TV provider says there have been a few other cases where decoders started smoking.
But with more than a million decoders in New Zealand homes, the company says a unit catching fire is "incredibly rare" and it does not believe the problem is widespread.
Kaukapakapa woman Claire Buckley told the Herald she saw flames and smoke coming from her Sky decoder on Saturday morning.
The mother-of-two had been on the phone to Sky about the decoder, which she said had just stopped working when it happened.
"I went, 'Oh my god, oh my god, it's on fire'.
"And the guy [customer service representative] went, 'Oh yeah, there's probably something really wrong with it - you should unplug it'."
The representative told her he would credit her for the loss of Sky and would send a technician on Friday with a replacement decoder.
Buckley said a technician visited her on Monday saying the flames usually came out from the front right of the box. Hers had flamed at the back.
Buckley posted a warning on her local Facebook page and at least three other members commented theirs had also caught fire.
Silverdale man Anthony Nann said he was watching Sky in June when his TV stopped working.
Seconds later he heard a bang and saw flames coming out the top, he told the Herald today.
An audio visual professional working at his house blew the flames out and unplugged the box from the wall, he said.
Sky sent a technician to replace the box, but a month later Nann and his wife were watching TV when they heard a massive "pop and a big bang", he said.
"It blew. The next thing the telly went off and there was smoke coming out of the Sky box again.
"This isn't on really. If I hadn't been home this could have burnt my house down."
Nann questioned whether a recall was needed.
Sky TV communications director Kirsty Way told the Herald she had never heard of a Sky box bursting into flames in her 16 years at the company and said no recall was planned.
She confirmed a few cases where they had started smoking, but was unable to provide details.
"Electrical appliances can on occasion 'short' and there may be a failure of the box and some smoke."
Way said the company had arranged for a technician to take Buckley's damaged decoder away so the cause of the fire could be investigated.
Sky "was not saying it had never happened before, but given the number of boxes versus incidents it would affect a small fraction of a per cent".
NZ Fire Service and Energy Safety had no record of decoders catching fire. Energy Safety had contacted Sky about the incident following Herald enquiries.