Solar hot water panels have fallen victim to this weekend's cold snap, bursting, splitting and leaving home owners with plumbing bills in the thousands.
Plumbers say they have struggled to keep up with unprecedented demand for help as temperatures plummeted. One plumber in Melbourne's west said he had attended eight jobs over the weekend.
Sub-zero temperatures were reported around Melbourne on Sunday, including minus 5.3 degrees at Coldstream, near Lilydale, and minus 2.5 degrees at Viewbank.
The cold snap caused water in panels to freeze and expand, resulting in snapped and split panels and broken frost valves.
John Willis from John Willis Plumbing in Lilydale, where temperatures were also below zero, said he had seen several broken solar panels over the weekend and that quality varied among manufacturers.
"There are various manufacturers of them, and some of them aren't really up to the job of the frost.
"The lady I went to yesterday tried to get in contact with the people that had put the system in for her and they were deregistered and had gone out of business.
"There were two panels on the roof and both had split with the frost."
Scott Edwards from S.A. Edwards Plumbing in Eltham said he couldn't keep up with demand over the weekend.
"I've just left one job and I'm going to another now. This generally doesn't happen every winter, just when we get bad frost like over the weekend."
Mr Edwards said quality solar panels with a glycol antifreeze system were generally more durable than cheaper models favoured by builders.
"There definitely has been one lot of units that I've done more of than others. Generally the ones that are bursting more often than not are the base model that builders put in."
Simon Marchione from All Sorted Plumbing in Keilor Downs said he had been to eight solar panel jobs over the weekend and that split panels could cost up to $2500 to replace.
"I've never seen anything like this," he said.
"There's a device on solar panels called frost valves. They allow a bit of expansion in the panel itself by allowing water to drip out of the panel. But we've seen panels with frost valves installed where it's still happening."
"I don't think it's a quality issue. It's more or less I don't think anybody expected for Melbourne to be so cold. They really aren't made for our changing climate."
Mr Marchione said damaged panels he had seen had caused no building damage and were only leaking water on roofs.
Since 2009, the Victorian state government has offered rebates of up to $1600 to households converting to solar hot water systems under the Victorian Energy Efficiency Target (VEET) scheme.
In 2008, the Rudd government also offered $8000 rebates to households installing solar power panels but scrapped the scheme due to soaring demand.
The rebate was part of of the Energy Efficient Homes Package, which also included a controversial home insulation program that resulted in the death of four workers.