Two port valve actuator replacement

I've done both.

In fact it was worse and better taking the whole valve out

I had a idsolation ball valve pissing water all over the adjacent MV and had replaced the head once already, then it popped the RCD and I realised that the gate valve needed to go and snce I had originsally bought a whole new MV and just used the head, I thought to replace the body as well this time.

Turned out that replacing the ball valve needed pipe cutting and a new bit of pipe inserted due to incompatible threads on te new ball valve vis a vis the old. A LOT esasier to do everyhung on the bench with a vice.

But the actual process was pretty easy. I de pressurised the system using the valve in the boiler and then simply unscrewed the joints with a bucket unbderneath. I got about a buckets worth of water out and the rest stayed in - made bleeding much easier.

But using the valve I wanted to replace as the drain point I only drained what I needed to drain.

If the MV has been sticking you PROBABLY really want to replace the valve BODY.

And get a valve that you can get spares for more easily. I got a honywell (allegedly) single port valve for half the price plumbing world sells one, off amazon.

Oddly enough I managed to dry out and clean the head and ended up not using the second replacment valve I bought, However I did have to take a soldering iron to the dreadful crimped connections to the motor BOTH of which failed in disassembly - (one had been buzzing before as well)

So IF te valve is in a place weher water can be mopped up and wont cause damage and you can get a bowl or bucket under the valve, just de pressurise and let the system drain at the valve. It's no big deal.

Thanks.

It's an open vent system so simpler than yours to deal with.

It's the actuator that's the problem: I've taken it off and the spring-loaded valve mechanism closes freely after I open it by hand. With the actuator in place, and the valve not closed when it should be, a firm tap on the actuator body persuades it to close.

I'm keen to get an actuator replacement for the Boss Therm BZV22/Siemens Landis & Staefa Replacement Motor Housing RMH as it's a really easy clip in, clip out fitting on the valve.