EPH controls Zone 3 lost connection

Have 3 zone heating with EpH controls. Hot water and downstairs works fine. We've set thermostats too high on purpose as don't want them turning on automatically.

However, upstairs, zone 3, is not coming on, the valve to call the boiler is not opening when Boost is pressed.

When I try to do the Wireless reconnect, only the red wireless light flashes intermittently then goes solid. The blue System light beside the red solid light, no longer comes on at all.

Is there a way to manually override this?

Do I need a plumber or an electrician? Thanks!