My signal dosn't work?

Hi
I have recently refurbished my house and unfortunately after refurbishment I couldn't find my thermostat anymore. I went to B&Q and the seller has advised me to buy a new Dayton thermostat and i should contact it wireless to the SCR.
I have tried several times with the over writing button but und can see my SCR is finding my thermostat.
Is there someone can help me with my issue.
Thanks in advance.