No water is flowing from any of the hot water taps

[Austin Williams]

Recently moved into a flat. We went away 2 days ago and all fine. Returned to find that there is no flow at all (not even a gurgle) from the hot taps (the whb and bath tap, nor the downstairs kitchen sink).
We have a very, very old gas boiler on the ground floor which feeds a small cylinder alongside. The cylinder has a loose fitting, 25mm mineral fibre insulation jacket. This system - and the central heating system as well - look as if they've been untouched for around 20 years!
I was wondering whether there might have been something (dislodged firring, maybe) that could have blocked the hot water feed pipe. It seems unlikely/ coincidental to completey block off all flow.
I just wanted to know if anyone had any clues what to do... and how dangerous (notwithstanding the age and condition of the system overall) is.
Also, a few weeks ago, we have had some trouble with overflow from the expansion pipe discharging into the feeder tank in the first floor bedroom (even thought the water wasn't particularly hot coming out!).
Any thoughts? Gratefully received.

 

[gas4you]

Check the ball valve in the cold feed tank for the hot water cylinder. It may have stuck up. If so wiggle it about a bit to release it. This may be on top of the cylinder if it is a fortic tank or it may be in the loft. You may also need a new ball valve if it is really stiff.

 

[Austin Williams]

Cheers gas4you. I sorted out the ball valve in the feeder tank (you're right it was stuck... mainly a build up of calcium stopping the ball valve from closing). That's sorted out the o/flow problem, but still worried about the lack of hot water flow. D'you think unfirring the system is the best thing...?

 

[kevplumb]

try clearing the airlock first if the tank has run dry

 

[Austin Williams]

Will do. Thanks. I'll let know how I get on.
Thanks again