worcester shower problem

[steveuktv]

hi folks i hope somebody can help.
I have a problem with a worcester 240 boiler in that all the central heating radiators work fine but the shower seems to run cold (or at most tepid) although turning on an hot water tap and slowing the flow down does increase the temperature enough to have a shower properly.
I might add (dont know if it makes difference) that i live in a bungalow so everything is on the same level and although the shower was ok for the last 4 mths or so it has gradually got worse.
another clue might also be that when i turn on the boiler it doesnt always start so i have to hit the reset button and it ignites and runs fine all day.
the bar pressure gauge also rises to 1 bar ...any clues....

p.s. from electrician who hates plumbing issues!!!

 

[spacethegas]

so hot taps ok ?
if ok shower prob.
why would you turn on the boiler. it comes on when required for hw.
when system cold set pressure to 1.5 bar.

 

[LUNAT]

HI


What sort of shower is it ?

 

[steveuktv]

ok forgot to say that i never see the DEMAND light come on ..and just to add to the confusion it has stopped working totally now......it ignites when the reset button is pressed ...strange gurgling noises come from system and then it shuts down.
after a while a click is heard and then reset may be pressed again...and how do i set the bar pressure ??? i am complete illiterate when it comes to boilers.
all was working fine last night and but today it refuses to warm up water or shower.
there is a chamber (red) with a valve on it ...does this adjust bar pressure and if so how do i do it?
excuse my ignorance.