No hot water despite boiler firing up

[boilerbasher]

I have a glowworm 30ci (my first mistake). Recently I noticed it was leaking water through the circlip holding the 3 way valve actuator in place when the central heating was turned on. I had a local plumber replace the actuator cartridge. The system seemed fine for a couple of days if a little noisier (vibration) than I remembered but that could be my imagination, but now we can't get any hot water.

If we're just asking boiler for hot water, the boiler fires up as it should but no hot water from the taps.

When the central heating is running at same time as hot water tap turned on we get the red light coming on with fault code F19 and boiler shuts down. F19 according to manual suggests that central heating NTC is not connected to the pipe, but the thermistor is attached. I guess it could be faulty and not registering but I'm a little suspicious of the error code as it seems to relate more to central heating than hot water.

Any ideas gratefully received, particularly whether you think the hot water problem could be related to the replacement valve actuator as I wouldn't wish to inconvenience the plumber by asking him to return if you guys feel the problems are simply coincidental.

Thanks in anticipation for any help.

 

[gas4you]

As the HW is controlled by the actuator head and DV I would certainly ask him to come back and check his work.