The answer to 'how much to fix backflow preventer in Chicago' is that the cost can vary widely depending on several factors. Backflow preventer repair and maintenance is typically done by licensed plumbers, and the price range is usually between $150 to $500 or more. The exact cost will depend on the type of backflow preventer, the extent of the issue, the labor required, and the hourly rate of the plumber.
Backflow preventers are critical safety devices that ensure water does not flow back into the public water supply, so it's important to have them properly maintained and repaired by a qualified professional. Getting multiple quotes from local plumbers is essential to ensure you get a fair price for the work needed.