I know this is an old threat but we literally have exactly the same issue. Did you ever get to the bottom of it? The smell for us is only when water is running through the shower or bath. Bath was added on to the existing shower pipework. It actually smells like its coming from the bathroom wall...
Thanks Dude, its wired up the way you said but just hot water not working in isolation as we expected. Didnt need gravity mode as I think its a fully pumped system. Shame its not as simple as bridging connections like the honeywell.
Thankyou for taking the time and level of detail. May get someone in. As it stands with it being cold its not a problem as the heating on anyway so can run the hot water. The issue will be come summer. Will keep you posted
Hi I recently installed the hive to replace my honeywell st699 as per the attached. I did the 8 to 3 like the solid dotted line rather than faint but when I press hot water only it does not fire the boiler. Is this because my baxi megaflow does heating and hotwater together hence the com wires...