Recently I upgraded my Evohome system with the latest evotouch controller (built-in internet gateway, electric zones, outside temperature display etc). I also replaced most of my HR80 radiator thermostats with HR92s.

The installation went very well.
I basically "started again", unbinding all devices (BDR91s, DTS92s, Y87RFs, CS92, HR80s). The HR92s were brand new. I used the guided configuration and had everything done in about 5 hours - most of that time was spent tweaking minor configs and settings.

Two weeks in, and the controller has learned the properties of each zone and the zone temperatures closely follow the configured set temperatures.

A few days ago I bought two new HR92s for two children's bedrooms. I'd replaced one of the children's HR80s with an HR92 during the main installation - and the other kids complained that their HR80s were noisier and less cool than their HR92-equipped sibling's!

I thought it would be a straightforward 10 minute job - but I hit a problem I thought I'd share here to maybe help others avoid falling into the same trap.

Here was my (with hindsight, flawed) plan.

Remove HR80 and remove batteries.
Fit HR92.
Bind HR92 to zone.

So far, all seemed to go well.

Then I wanted to disable local temperature adjustment. I did this from the zone config menu on the evotouch.

What happened next was unexpected... both HR92s displayed "blocked" on their LCD - that's all, just "blocked", no icons or temperature. Pressing the button caused the display to show as normal - but it would return to "blocked" after a few seconds. Rebinding, resetting the HR92 to factory settings both had no effect. (Note that the HR92 worked as expected under evotouch control - it was just the display that was "wrong".

Deleting and recreating the zones, then binding the HR92s also didn't solve the problem.

Because I was seeing the same issue with both HR92s I concluded that it was unlikely to be a hardware fault and more likely to be some obscure config issue, but repeated, and VERY CAREFUL following the installation manual didn't provide a cure.

I called Honeywell tech support and the engineer there basically took me through the same routines I'd already tried. He concluded that he had no answer. I suggested that perhaps I should try removing the HR92 batteries, pausing, then replacing the batteries. (By removing I mean opening the retaining clip).

This did the trick!

In summary, if you plan to swap an HR80 for an HR92 on a system using the latest Evotouch controller, first, delete the zone and then recreate it from scratch. Don't think think that removal of the HR80 and binding the replacement HR92 will do the job!