I’m having a problem with my single port Honeywell motorised valve on the hot water circuit. Everything was working fine until problems began this week with a failure of the spark generator in the boiler. Had this repaired now the hot water motorised valve won’t work. I’ve changed the syncron motor and still not getting anywhere. I can use the override lever to get hot water, but the valve won’t energise. Nothing has changed, just stopped working. It’s wired in accordance with the S plan and is a split circuit upstairs and downstairs. CH valves working ok, but when Hive calls for hot water, no response from the valve. I’m stumped!