sandra.finch wrote:
I've been looking everywhere for an answer to a problem which has recently
befallen me. I suddenly can't get any hot water in my taps unless the
heating has been on. Is it connected to the fact that I had a very noisy
actuator motor for a couple of months and now I don't hear it at all?

Very probably

If any one can offer an explanation and, even better, a solution I would be
very grateful.

If it's the motor part of the valve, this can usually be replaced
without plumbingy work.

If it's the valve part, it's a drain-down job.

Owain