Some companies in Wellington and Christchurch are reporting an influx of people wanting their services after the incident.
People became nervous about safety, and anxious to get their gas systems and appliances checked, the companies said.
The explosion in Northwood last Friday injured six people, one critically, destroyed a home and made nine nearby houses uninhabitable.
Foleys Dunedin hub manager Craig Foley said there was no major change in demand for its work since last week.
The company would be busy at this time of year regardless, he said.
The sentiment was echoed by representatives of two other Dunedin gas-fitting companies, who did not want to be named.
"There hasn't been a noticeable increase," one said.
Foleys Queenstown branch manager Sam Mitchell said it also seemed to be business as usual there.
"We haven't noticed a difference - it's been busy for the last four years."
However, on a couple of jobs in the last week residents asked more about whether the systems had been tested properly.
Ultra Gas and Plumbing owner Brian Haldane, of Invercargill, said he noticed a "slight increase" in requests for inspections in the last week.
"But some of them will say `oh no, that's too dear'."
The owner of another Invercargill gas-fitting company said there was no change in the number of requests.
Hutt Gas and Plumbing Systems general manager Colleen Upton, of Wellington, said winter was always a busy time, but there had been another surge of calls from customers and the phone had "gone berserk".
"They're booked up pretty much ... right to the end of August."
