Our pool heater started acting up and after hiring AirOne I was told that one of the switches was defective. I agreed to the fix and was then told all the switches needing replacing - apparently a package that couldn't be split up, even though only one switch was defective. I agreed, thinking it would be an investment for the future, and in less than a year the main pressure switch had also stopped working.
Initially AirOne claimed it hadn't been replaced and wanted to charge me for a new one, going so far as to claim they didn't carry the type that was installed. This changed when I showed them their receipt - which they said they couldn't find - showing they'd done the initial replacement of ALL switches including the now-defective pressure switch.
I later had a problem with the heater burning dirty. Their assessment was that the heat exchanger was sooted up (isn't that why I called them in the first place?) and the whole heater needed replacing, a $3000 job. The technician never even looked at the burners to see why the fuel was burning dirty, and told me the typical lifespan for a pool heater was 5 years and I should be happy with what I had gotten to that point. Problem is pool heaters manufacturers will quote an 8-12 year life span...
Don't trust them.