Heating airlock cleared but no Hot Water

[Silverpenny]

Everything was working fine until I had to drain the system down to replace some radiator taps, after refilling no hot water, radiators wouldn't fill/vent and of course boiler only ran for a minute at a time until cutting out.
After reading other posts I put mains pressure hose down the overflow in the loft, which obviously did something beneficial as all the radiators then vented and we now have a warm house again. Hooraaaay!

But.. ..no hot water, the immersion heater upstairs and the pipes to the coil are stone cold. Still an airlock here? Strange because I'm sure the overflow pipe I fed water into is the pipe connected to the top of the coil just a few feet below.

Do I need to give it another blast of mains pressure?

In the course of original faultfinding, I re-programmed my Siemens RWB9 timer, could that be playing up, even though HW led is on?

Maybe my motorised valve stopped working, or if I knew where it was (!) I could use manual overides to faultfind? Where IS the motorised valve??!! (I have a Potterton Kingfisher Mf boiler down in the kitchen)

Thanks in advance for any advice you may have, or alternatively, if you live in Oxfordshire, could we pop round to your place for a quick bath?

 

[Silverpenny]

I'm lucky, the airlock affecting the hot water system seems to have cleared itself and everything is back to normal.
Still curious to know where my 3 port valve is, no mention of it in the potterton literature but i guess it must be near the boiler somewher??

 

[JohnD]

If not beside the boiler, is probably beside the hot water cylinder. Is likely to be next to the pump.