No hot water but CH is fine

Today I shut off out cold water supply and drained the hot and cold water in order to change kitchen taps.

I've now opened up the stop cock, and water is now flowing again, but the hot water supply is stone cold. I've turned the gledhill and the boiler off and on. I've checked the F&E tank and it is full, and the ball cock works fine. No obvious errors inside the gledhill.

Water seems to flow fine from hot supply, will go slightly warm after a minute and then go stone cold.

I've also tried putting the boiler into Switch mode, again, same symptoms. I'm not a plumber so be patient

Check the DHW pump.
Bleed it.
Weird though as you should have been ok in theory.
Mike
MGC/H2O
Norfolk