Work not inspected before fatal shower

A 12-year-old boy died of carbon monoxide poisoning after a gasfitter signed off a hot water unit that never should have been installed in the bathroom the boy used.

Jesse Samuel, of Alexandra, was found slumped in a small shower unit at his family’s holiday home in Haast on October 10, 2018. Gasfitter Michael Cartwright and plumbing company Central Plumbing Ltd, which trades as Laser Plumbing Alexandra, will be sentenced over the boy’s death in the Dunedin District Court next week.

Cartwright and his company pleaded guilty last year to two charges under the Plumbers, Gasfitters and Drainlayers Act (2006).

The summary of facts says Gary Hale, a registered plumber and gasfitter who coowns Laser Plumbing Alexandra with Cartwright, was employed by the Walker family to install a gas hot water unit in a portable bathroom. Cartwright, a certified gasfitter, was responsible for certifying Hale’s work.

Brendon Walker, Jesse’s uncle, bought the Bosch hot water unit in September 2016, and was told by the retailer that it was suitable for the small bathroom unit.

The bathroom was initially used at Walker’s home in Alexandra while his property was being renovated. A shower, basin, toilet and sliding window were later added.

The water heater was described as an open-flued instantaneous water heater. It worked by taking fresh air from the room it was installed in and using that air for combustion, the summary said.

To avoid carbon monoxide entering the room, the unit had to be installed in such a way that the room would have adequate ventilation, while the combustion would be vented from the flue. Instructions for the appliance included a warning about how it should be installed, and a warning sticker was attached to the unit itself. The sticker urged the installer to read the instructions, and stated that the unit should not be installed in a bathroom.

Hale installed the water heater in the bathroom, but did not raise any concerns about it with Brendon Walker. Hale was a tradesman gasfitter, so his co-director, Cartwright, had to certify the installation.

The summary of facts says that Cartwright never visited the bathroom, did not inspect the water heater or carry out any tests, and did not question Hale about his work.

The Walker family always opened the bathroom window and used an extractor fan when using the shower, because the unit filled up with steam otherwise.

In 2017, the pipework split, and Walker asked Hale to repair it. His company was not able to do the work, though, and the unit was sent to a Wa¯ naka-based firm. The family then decided that the shower unit should be moved to their holiday home in Haast.

Walker installed an identical gas unit in the unit, using the same fittings Hale had installed and Cartwright had signed off. The company and Cartwright dispute this.

Several people stayed at the home over the following weeks, and were told to keep the window open when using the bathroom because of the steam.

Jesse stayed there with his family during the school holidays, but was not told how to use the shower. He used it for the first time about 5pm on October 10. His mother, Justine Walker, found her son’s body slumped on the floor behind the closed bathroom door. Paramedics were unable to revive Jesse.

An autopsy found that Jesse’s blood level was 59 per cent saturated with carbon monoxide. Other tests showed that the shower unit could reach 1400 carbon monoxide parts per million (ppm) in just eight minutes. WorkSafe’s guidelines recommend that workers be exposed to no more than 200ppm over a 15-minute period, and state that a worker must never be exposed to more than 400ppm.