Vaillant VRT50 Room Thermostat

[cammsjb]

Hi

Please can anyone advise me.

I have a Vaillant ecotec exclusive 838 pre-2012 model combi-boiler at home which is currently time controlled with a Horstmann Centaur plus C17, 7 day timer which is wired through a Vaillant VRT30 stat to terminals 3 & 4 on the boiler control panel, my VRT30 room stat has now failed & needs replacing.
My thoughts are to replace this with a Vaillant VRT50 ebus stat which I believe should be two wired directly to the ebus terminals on the boiler control panel.

My question is, will the Horstman C17 timer still time control the boiler if it is two wired directly to terminals 3 & 4 with the VRT30 removed & the new VRT50 wired to the ebus terminals, if not can anyone suggest an alternative way that this combination of controls would allow the boiler to function satisfactorily?

 

[mrStat]

Should work fine, you need to wire the existing Horstmann into 3&4 on the boiler PCB, and then the VRT50 stat into the eBus. Manual (page 3) states that 3&4 need to be linked.... As such, if the clock breaks the 3&4 connection, heating should stay off. Good luck.

 

[cammsjb]

Thanks for your advice, I wired up the Horstmann timer today as sugggested and all seems to be working fine so far.