i have recently changed the low pressure switch on my modena 102 combi boiler, it was workin great for 2 weeks, but suddenly the hot water has stopped comin through and the boiler is showing low pressure indicated by flashin lights, i changed the low pressure switch again, now the central heatin works fine , but when the hot water taps are turned on with the heating on , the boiler shuts down to low pressure, with light flash, showin low pressure , even though water pressure is fine , central heatin on its own works ok and the warm water,, but not both together,,,,,,keeps shuttin down to low pressure ,,, help,,, cheers

couv, October 2007

cheers ricky,

the hot water works good, but the both dont work together , throws boiler into low pressure mode,, with flashin light 5, then i have to reset,, but the heatin is very stop start , but like you said, and i am gettin the flashin light on waitin for heatin to come on with a delay of between 1 to 3 minutes,, so will try what you said ,,cheers for your advise,,,

couv, October 2007

can you check it is the bottom light i think you may find it is the light above which would come on if there was possibly a fault with the hot water flow meter starting to work then failing causing the boiler to go to waiting time which would last for approx 1 to 3 minutes this would appear as a flashing light if this is the case use a 19mm spanner to remove the internal part ot the flow meter give it a clean and reassemble in the reverse order but you must turn off the cold water first also check to make sure the hot and cold pipes are not reversed this could also cause it and finally check the hot water thermister hope this helps

ricky, October 2007