Vauxhall took the decision despite a first recall in December 2015 to correct the issue, which the manufacturer said was caused by improper repairs to the people carrier’s blower motor resistor.
Described by the car maker as “preventative action”, the latest recall will involve “improving the overall robustness of the system” as opposed to simply replacing the resistor and its fuse, which the firm started doing last year.
In November 2015 the London Fire Brigade said it attended 71 Zafira fires - not including arson attacks - since 2013, compared with just 38 in the previous four years.
In December Vauxhall wrote to all 234,938 Zafira B owners regarding the problem.
It said improper repairs of the blower motor resistor and its thermal fuse, which is designed to protect the blower motor system, could lead to overheating of the system’s electrical components and the potential for a fire.
Announcing the new recall on Thursday, a spokesman said: “While the current action achieves the objective of returning vehicles to their original condition, after extensive investigations we have decided to go further and improve the overall robustness of the system.
“We will therefore be initiating a second recall to replace the current soldered fuse resistor with a wax fuse resistor so reducing the opportunity for manipulation.
“When the recalls are complete, all vehicles will have a new wax fuse resistor, a new blower motor and a new moulding at the base of the windscreen to address water ingress.”
Both recalls have been free for car owners and the company will be writing to customers soon with information. Letters inviting them into dealerships for the second recall are expected to go out in August.
Drivers who have not yet had the work from the first recall completed should still take their cars to dealerships, Vauxhall said.
Jacqueline Young, head of group litigation at Slater and Gordon which has been representing Zafira owners who have suffered fires, said: “If the findings are true, at best, Vauxhall has been woefully incompetent; at worst, they have sought to conceal a potentially life endangering technical fault - the public deserve to find out which is it.
“Will this prove to be yet another scandal where major motor manufacturers show scant regard for their consumers and prioritise profit over safety and/or performance?
“The situation also begs questions about the efficacy of the DVSA [the Government agencies dedicated to monitoring manufacturing or design defects, highlighting safety concerns and monitoring safety recalls]. In the current circumstances, it is difficult to view them as anything other than a toothless tiger.”
She advised Zafira owners to contact their local Vauxhall authorised repairer to arrange a free safety inspection and repair. For the owners of Zafiras that have burst into flames, she said any insurance claim could affect their insurance premiums.
She added: “They will also potentially be out of pocket for any uninsured losses. If Vauxhall is responsible, these losses can viably be claimed from them. Any customers who have suffered a fire should explore these issues with their insurers.”