this has turned into a real bug bear - i cant work it out. even with the testing above. i recognize its hardly a bad problem in the current environment though. if i turn the heating zones off - the valves make a sound, and the pipes post the valve slowly cool down. i dont find anything...
stem and others -- thanks for all the advice. i will perform the test above tonight and report back. i can confirm there is no wire in terminal 2, it is an optical illusion.
once again - appreciate all the inputs. there is definately no connection to 3 (HW on). there is a black wire to 4 (CH on) and brown wire to 1 (HW off). the wire from 1 looks to go into a wago 221 connector and link to the L wire. airing cupboard is per the attached.
Thanks all for the responses. It is the ultracom hxi model. I will take some airing cupboard photos when home – to answer the question around why I didn’t think the HW was controller by the timer – I turned the timing mode to OFF last night on the HW side, however the water was still perfectly...
Hi all. Appreciate any help in understanding wiring set up in new build home. We have a glowworm ultracom 24 boiler. Honeywell st9400 programmer downstairs. 2 Honeywell cm901 thermostats -- one upstairs and one downstairs. We also have a tank in the airing cupboard. I would like to understand...