you could add a HepvO trap on the shower.
http://www.hepworth.wavin.com/master/master.jsp?products=products&middleTemplateName=oc_middle_system_detail_I&FOLDER%3C%3Efolder_id=2534374305508362
one thing to check is that the solenoid valve isnt letting by.the only times power supply problems do strange things to boilers is if you had a power surge,but they usually fry the control box.
1 an 2 are the fillingloop connections,3 is the cold water inlet isolator.
the valves are in the open position when the slots in them are facing front to back.if you look on the wide part of the grey knob it will have closed written on it to show you which way is is when off.
you may have a blockage in the rad itself of in the pipework.the only way to check is to drain the rad and take it outside and flush through with a hose.then connect a hose to each of the rad valves and turn on to flush some water through.
just wondered what other area scrap dealers were like.i stripped down a powermax with a copper cylinder that weighed 31kg,after their story about theres stainless in it we lose money blah blah they only offered me 18kg,that to me is £40 down on what i think i should have got.
just wondered what your experiences of taking in scrap cylinders were.
where i take mine they dont weigh them jost allow you 10kg, even if they are unlagged and clean.
if a technicians tap works it could be a loose connection,these things are not servicable,you may need to replace it.
http://www.screwfix.com/prods/70280/Bathrooms-Showers/Showers-Enclosures/Shower-Pumps/Salamander-Shower-Pump-2-0bar-Pump-with-Isolators-CT75
extractors can be vented through the tiles with a lead slate and a mushroom cap on the pipe,or use an inline fan and vent through the eaves.you may ned to fit a condense catching pipe if its a long run.
if you have a leak on a sealed system the pressure will drop as everyone knows,but that doesnt mean that air is sucked into a system that is above atmospheric pressure.thats why i think its gassing in the system.i fitted a system many years ago where each week the pressure was down and the...