The replacement for the Heatmiser UH3 is the UH8 available here.
https://www.heatmisershop.co.uk/heatmiser-uh8-8-zone-230v-wiring-centre/
The replacement for the Heatmiser UH3 is the UH8 available here.
https://www.heatmisershop.co.uk/heatmiser-uh8-8-zone-230v-wiring-centre/