I have an eco tec 428 boiler running in sealed system with VR66 VRT350 wired and A VR10 NTC sensor, System runs well in central heating mode but i cannot call DHW VRT timer is set so that DHW is on, VRT350 shows hot water temp in installer menu and boiler off during DHW demand time and HEATING during CH time, i know that the VRT350 is good and ebus wiring is good (twisted pair screened cable) measuring volts across CH1 i see 230VAC in CH mode but i see nothing across DHW on, i have swapped out the VR66 without any success hot water tank is Vaillant unistore VR10 in dry pocket two 2 port valves
Can anyone give some suggestion as to a possible cure
Can anyone give some suggestion as to a possible cure