G
Gardner
Hi everyone, I'm new to this forum but could do with some Help & sound advice on my heating system I had a Baxi Solo gas boiler running with my boiler mate ll then we changed to a vaillant 418 ecotec boiler but now im having trouble with lower pump on BM ll it seems to vibrate along with the pipe and makes a noisy droning sound only when the heating is on or we draw hot water to shower etc it sounds like air in the system plumber fitted automatic air vents bled rads I have also noticed that thermostat on B M ll is switched to minimum setting summer mode only on one click otherwise green neon will not go out my only concern has the boiler been wired up correctly there's a 4 core cable only 3 wires are being used which are green or a yellow colour blue & earth there's a red wire folded back out of the way should this be used as it was on the Baxi solo