I think you are right. In my case, they found it hard to tell what stuck the first thermostat. Lotus NA made the call to replace both. Fingers crossed, this was my Lotus glitch. At least I got to wrap codes, updates, 1000 mile service and new car issues all sorted at one time.
Picked mine back up from service Thursday afternoon. Drove 225 miles to get home and the car was flawless. Replacing the pair of thermostats followed by vigorous test drives seems to have done the trick. Time will tell but currently I'm confident in the work that was done to sort this issue out.
3 week update. Both thermostats are being replaced. Then another flush and then a "spirited" drive rest and repeat sequence to make sure everything is all good. It's taken a bit to get the parts and go through the process. Fortunately, i have other cars to play with. Note- if you get the...
Got the word that "thermostat stuck" is the issue. Replacement is the fix. Seems they've had a few of these with this issue. Looks like there are 2-3 updates available- not sure what they are for but happy to hear it all the same.