Chlorine blamed for spike in cylinder damage

Wednesday, 15 August 2018

Chlorine is being blamed for thousands of dollars worth of damage to water cylinders in more than 60 Christchurch homes.

The controversial chemical, which has been added to drinking water since March, may have led to leaks in pipes and cylinders, leaving landlords with a $2000 replacement bill.

A large number of plumbing faults have been reported by four separate property management firms, while one manufacturer says demand for new cylinders has doubled.

Although the exact cause of the failures is not known, it is thought the chlorine may dissolve sediment, revealing cracks, or remove the oxide coating from the copper.

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Prudence Morrall, director of The Good Girls Property Management, said the number of faults with cylinders since March was 'unprecedented'.

'There's potentially hundreds of properties affected by this. The chlorinated water causes a chemical reaction and the pipes can't cope. We've had eight or nine go and the owner has to spend $2000 to fix it.

'Lots of these were replaced post-quake. For cylinders to go after only six years is unacceptable.'

Morrall said the city council had failed property owners and action needed to be taken.

However, John Mackie, head of council's Three Waters and Waste team, said cylinder-related failures were occurring 'long before' Christchurch's water supply was chlorinated. 

Plumber John-Paul Bridger, of Aquafire Plumbing and Gas, has replaced two 180 litre low-pressure copper cylinders in the past week.

The issues being reported could be the tip of the iceberg, he said.

'I've seen a lot of cylinders go in a short space of time and colleagues have said the same.

'When I examined one there were half a dozen holes. It couldn't be fixed, the whole unit had to be replaced. Unless the cause of this is diagnosed and a preventative measure is found, this could affect a lot more households.'

Pam Marshall, general manager at Iron Bridge Property Management Group, said at least 20 properties had reported cylinder faults since March.

'There's been a big increase in the last five or six months. We specialise in mostly newer properties, many are only a few years old, so you wouldn't expect the cylinder to be replaced in that time.

'Some have been fixed but the majority of cylinders have had to be replaced.'

Tony Brazier, of Brazier Property Investment, said 23 cylinders in properties his firm managed had been damaged past couple of months. Cylinders in four out of five of our properties in Brockworth Place had had to be replaced.

'It's no coincidence that these faults have occurred since chlorine was added to the water,' he said.

Caroline Register, of Harcourts Holmwood Property Management, said the firm had also experienced similar issues in nine properties across the city.

Trevor Edwards, managing director at manufacturer Superheat, said the firm had doubled its usual number of cylinder sales in recent months.

There could be several reasons for the problem, he said.

'Copper has an oxide lining that could be stripped by the chlorine or it could be due to the removal of sediment that has built up. What we need as an industry is to find the actual cause.'

Industry professionals were meeting with the city council on Friday, he said. Havelock North, which began chlorinating after a deadly gastro outbreak in 2016, experienced cylinder faults also.

'The failure seems to be in older cylinders. Plumbers are telling us older stock, from 10 to 20 years, are the most common to fail. The stock in Christchurch is quite new because of the earthquake.

'The problem may or may not have been know but the fact it's happened a second time is significant.'

Mackie said the council had not noticed an increase in calls coming in for cylinder-related failures compared to pre-March 2018.

'We will follow up on the issues raised by looking at the failure rate in our social housing units which are spread across the city,' he said.

'We encourage people to make sure they check with their installer that the cylinder is fit for purpose, has appropriate galvanic protection and is installed and serviced by a suitably qualified tradesperson.'