Hi
Looking for confirmation really.
I'm about to replace an ageing Hortsmann Diadem H425 programmer with a new H27XL model. According to the Horstman literature it's a direct replacement. I'm also going to add a Horstmann HRT-4B room thermostat - there is currently no room stat installed.
The installation instructions for the room stat suggest that only two connections need to be made between the room stat and the programmer - terminal 1 (common) to position 4 on the programmer connector block (CH On), and terminal 4 (call N/O) to white on the three port mid position valve.
Can someone confirm this is correct - or have I missed something.
The system is fully pumped with a cylinder stat.
Sorry if this is a 'daft laddie' question.
Looking for confirmation really.
I'm about to replace an ageing Hortsmann Diadem H425 programmer with a new H27XL model. According to the Horstman literature it's a direct replacement. I'm also going to add a Horstmann HRT-4B room thermostat - there is currently no room stat installed.
The installation instructions for the room stat suggest that only two connections need to be made between the room stat and the programmer - terminal 1 (common) to position 4 on the programmer connector block (CH On), and terminal 4 (call N/O) to white on the three port mid position valve.
Can someone confirm this is correct - or have I missed something.
The system is fully pumped with a cylinder stat.
Sorry if this is a 'daft laddie' question.
