N.B : Not a plumber / electrician but fitted myself !
N. B. : Both Valve & actuator had to be replaced as older type similar valve was faulty & leaking.
Not too difficult to fit with basic plumbing and electrical skills and a vented heating system (header tank in loft).
I waited until the system cooled down, and then turned off ALL POWER. Went into loft and ‘bunged’ header tank on both feed and expansion pipes. Closed isolator on one side of the heating pump and then ‘cracked’ one valve nut slightly open with a bucket underneath to catch any water (approx 1/3 gallon from upper pipework to header tank came out). Once water stopped dripping I undid second valve nut to completely remove old valve and replace with new (PTFE tape around old olives). I then reopened isolator to heating pump, Un-bunged’ F&E tank in loft and then waited for pipework to refill with new valve open. I wired in new actuator as per old one (ALL POWER STILL OFF) and then ‘clipped’ onto new valve . After checking everything and with no leaks, turned power back on, including boiler to check etc. - all good, no leaks and working fine. No air found in system, but have bled highest rads just in case now and again.
Hope this helps, but have a plumber’s name handy, just in case !
Verified purchase: YesCondition: Pre-owned