Control Valve failed

Need some help please.

when starting the counter, as it is checking the metering system it beeps and stop saying control valve failed. we changed the control valve pump but still get that same error.

anyone have any idea on other things to check or replace? is it possibly a clogged tube? if so which one?

please email me at Glenz@Coh.org or call 6264084297/

Thanks!