Central heating won't work since boiler serviced

[CW1]

... on Thursday. It's a Worcester Bosch Greenstar Si30. Both the thermostat in the lounge (where I usually set the timer from) & the boiler are displaying the symbol which indicates the ch should be on. I managed to get it going yesterday, but don't know how, & it just got hotter & hotter, taking no notice of the 20° I'd set it to on the thermostat. Don't know how I managed to switch it off either, I was fiddling with it so much.

The company that did the service won't respond (1st & last time I use Groupon !). Seems to me the boiler & thermostat aren't synchronized. Could that be a possibility, & how do I sort it out ? I'm freezing - again ! :((

[CW1]

Sussed it !!
They HAD lost synchronization. Found a Digistat manual online - always wondered what the 'Lrn' setting was on the boiler ...

[The Builder]

Phew .......... been racking my brain here for something helpful to suggest :o(
Glad you're sorted CW :o)

[AlBags]

Another one who doesn't read manuals TB ... Cuhhh!

: )