ESi RF Programmable Room Thermostat. ESRTP4RF

[stevels4]

Hi everyone,
I have the above controller and want to install it on a Vaillant ecoTEC Plus 838H boiler, the programmer instructions are vague to say the least but there appears to be 2 options.

Method 1 live link pin 1 of the controller receiver and use a single wire to connector X1 connection RT

Method 2 connect pins 1 and 2 of the controller receiver to connector X100 connections RT and 24V.

Just to be clear I am both electrical qualified and Gas Safe registered just not been faced with this combination before.

Any advice would be appreciated.

 

[EricMark]

I have also looked at the three methods and wondered why, I would say ebus first option, but can only use ebus when there is one single thermostat, and the thermostat you have is not modulating type so no option to use ebus, so where using zone valves no option but to use 230 volt in many cases as often the zone valve is linked in some way.

So one wonders why we still have a 24 volt option, and if the programmable thermostat is in the future swapped for one which can be linked to TRV heads if using 24 volt they could damage boiler using 230 instead of 24 so seems safest option to use 230 volt.

I am also unsure about cables, with 24 volt or ebus it should not be run with 230 volt, but you often need a round cable to seal on the cable, and looks neater with one cable rather than two.

So I would use 230 volt option. I have not heard of any problems running 230 and 24 or 48 volt together EMC wise, but I have heard some boilers the RF from the boiler can cause problems if the thermostat base is too close.

Maybe some one will point out why there is a 24 volt option, I would not want to mix 24 volt and 230 volt in same cable, so to avoid that either base needs to be 24 volt or battery powered or the 230 volt option is used, with ebus OK no option have to run two cables, but with simple on/off 230 volt in most cases.