Merlin: Can't say I have item for you, but.. I modified a t'stst cover to only allow access to the temp up/down buttons and not the other controls. Depending on the t'stat you have, and how much time and work you can invest that may be your only choice.
The other option is to install a 'slave/master' t'stat. Lock the master & the slave unit could control temp adjustments only.
