Can temperature sensor replacement on a heat pump be a DIY project?

I have a 5- to 6-year-old EUS Mark VI heat pump, with Hayward branding. I'm getting an error code for a faulty temperature sensor. A pool company I contacted verified it needs a temp sensor, as they put some kind of temporary device on it to test the theory and the pump worked like a charm.

In any event, the company has not gotten back to us in 8 weeks, probably due to another part of the job that they were less than enthused about doing.

We really want to use that heat pump YESTERDAY! Neither DH nor I know anything about the pump, although we can take it apart. Any chance the replacement of this sensor is straight-forward and could be a DIY task?

If not....any ideas who the best repair company might be? Another pool builder? An HVAC company? A pool maintenance company - the kind that does mostly cleanings? I have no idea who built this pool, so can't go back to an original builder for service.

Thanks