The consumers price index rose by 5.3 per cent over the June year and the unions said the escalating cost of living was behind their claims.
Negotiations for the renewal of the company-wide collective agreement have been going on for more than three months.
The company, which was once part of Fisher and Paykel Industries before it was split into healthcare and appliance divisions in 2001, designs, makes and markets products and systems for use in respiratory care, acute care, and the treatment of obstructive sleep apnoea.
Under the essential services provisions of the Employment Relations Act 2000, the unions were required to give 14 days' notice of industrial action. This notice, which was lodged on September 6, provided for a reduction in factory output.
"The planned action is designed to ensure no health risk to company clients, but sends a strong message that Fisher and Paykel Healthcare employees are prepared to take action for what is fair,'' the EPMU said then.
Fisher and Paykel Healthcare's net profit after tax but before non-recurring deferred tax charges was $64 million in the year to March 31, down 11 per cent from the previous year, reflecting the strength of the New Zealand dollar and expenses relating to the establishment and expansion of manufacturing facilities in Mexico.
The company's shares last traded at $2.23, unchanged from Friday's close. The share price has been in a steep decline since hitting $3.30 last October.