Thanks but I'm still confused, sorry if I'm being stupid but you say connect L1 where the link was to L? (240v mains).
I meant L on the RX1! L1, N and Earth are the mains input to the boiler. Connecting Boiler L1 to RX1 terminal L and Boiler N to RX1 terminal N provides the RX1 with power.
I get the 240v supply bit and that the L1-L3 link is where I'm wiring in the boiler but the RX1 control end is where I'm confused. It says to link terminal 2 to mains which I'm not sure I need to do. And which of terminal 2,3 and 4 do I need to connect to L1 and L3.
This is where I might confuse you more.
The mfr instructions say that L2 and L3 should be linked not L1-L3. The difference is that L1 is
permanently live, while L2 is only live when the boiler is ON at the timer.
The mfr instructions for fitting a thermostat assume you are using the internal clock, so you fit the stat between L2 and L3. But you are fitting a programmable thermostat, so the internal boiler clock is redundant.
You have two choices: bypass the internal clock completely, or set the internal clock to run continuously. I think bypassing the clock is better as it avoids any chance of someone causing problems by fiddling with the internal clock.
Here is how you do it:
This is where I change my original instructions
You only need a 3-core (plus earth) cable.
* Remove link in the boiler.
* Brown to Boiler L1
* Blue to Boiler N
* Third wire to boiler L2
At the other end:
* Brown to RX1 terminal L
* Blue to RX1 terminal N
* Third wire to RX1 terminal 3.
* Connect a link between RX1 terminals L and 2
Come back if you are still confused.