Biasi Riva 24s timer replacement

[crandall]

I've got the old Riva 24S and the timer's pins are getting a bit loose.
Everything else still works fine.
I could just replace it, but for convenience (e.g. easier programming, an override switch to give an extra bit of heat without having to reset the timer etc)I was thinking to wire in a new remote timer instead of the onboard mechanical one.
I'm fairly competent at electrical and mechanical repairs.
So, can anyone help with the these questions:
1. Can the timer be easily replaced with an external one?
2. Any recommendations as to type, make etc.
3. How is the connection made (I've got the original wiring diagrams).
4. If I can do this, should I disconnect the old timer unit?
5. Anything else that in my ignorance I forgot to ask...
Thanks in advance.

 

[transam]

got a room stat ?? change it for a programable type , leave existing timer on constant ??????

Edit u may not have enough wires going to the existing r stat ??

 

[crandall]

Thanks for quick reply.
I've not fitted a room stat, but could easily wire one in - there are connections.
Either
"2-wire thermostat (240 V only)" - which I guess is what I need
or
"2-wire thermostat with delay resistor (240 V only)"

So - will any programmable stat do or should I get a particular type? I did a quick trawl and there seem to be a lot that work off batteries - e.g. Salus RT500, Honeywell CM900, Timeguard TRT035 etc. so if I find one with the features I want are these suitable?

I don't need anything fancy. The boiler's in the kitchen and easy to get at. I can just put the stat on the wall fairly close to it, and I will only need to use the timer function.

 

[onecog]

Hi.
Here's a 24 S wiring diagram if it helps ?
View media item 54143 View media item 54144

 

[Agile]

You can keep the old timeclock in place and just move the sliding switch to the 24 hour position.

Different versions of that model used different wiring positions for the thermostat and so its best to look at the connection block where they should be marked.

Tony

 

[crandall]

I think I've got a good idea of what to do now.

Many thanks to all for the information and the quick responses.