combi 80he plus

[roxey64]

hi every one first time in here so lets see how it goes
i have a baxi combi 80he plus boiler that keeps cutting out.
i do need to top up now and then but always before it gets below 1 bar pressure
as i have a leak some where but for the life of me i am unable to find it, checked all reds and nothing. taken floorboards up and still not a drop but that means topping up the pressure once every two weeks ish but now the boiler trips out with 1 to 1.5 bar still in and can happen 4 or 5 times a day so you can guess i am not a happy man i have had a plumber out who is corgi registered and he said something like the tank was empty and needed to be refiled which he did and i got a £50 bill for but still the problem is here any help would be greatly appreciated thanks

 

[twgas]

check discharge pipe that goes outside, if exp ves needed repressurising it would have been dumping water. try tying a pastic bag over the end of it and see if any water is discharging. The cutting out could be air in blr or if you've been topping up fortnightly for some time it may be caused by sludge, produced by the air in fresh water.

 

[roxey64]

discharge pipe was leaking out water but has stopped since work was done on it but if pressure don't drop why does it cut out? as for sludge all water that comes out of reds has been very clean