Danfoss Randall 102 replacement

[LJW61]

The timer/clock on 102 fitted to my mothers system is kaput, Ive sourced a couple of cheap 102's & a few (cheaper) 103's , presuming the 103 is an upgrade(?) could I install this , will this fit directly to the 102 backplate?
Cheers

 

[Boilerman2]

NO the 103 is NOT the same as a 102!!! one is a simple Time clock (1 channel) the other is a basic programmer (separate O/P for Pump)
Not compatible without some rewiring, you need a 102 (mechanical) or an E102 (Digital) both will straight swap on the existing back plate

 

[LJW61]

Many thanks !