One of the motorized zone valves Honeywell V4043H in my central heating system have failed. I have confirmed that if I use a new power head, the valve still does not close when no power is applied.

Since removing the whole body is difficult because of lack of access, I would like to know if it is equally effective to replace just the Ball & O Ring Kit- Part 272742A

Are there any considerations that I should be aware of?

I have replaced the heads and bodies in the past, but never just the ball and O ring.

What about using the Honeywell 40003918-007 sealing plate and ball kit? It seems a safer bet.

Thanks,

Antonio