Combi Boiler Problems Please Help? Over the last couple of months iv be having problems next to...

Over the last couple of months iv be having problems next to my combi boiler (alpha c23). Sometimes it works fine but most of the time i have no heat and on and off hot wet.The timer is set to be on all daytime but it will come on 3 or 4 times during the day for a couple of minutes next pack up again. If i run the hot water it will pilfer several minutes to actually attain hot water and again it will simply last a few minutes. I own had corgi registered plumbers up twice but niether hold fixed the problem, both say i be needing the portion they replaced. I really dont want to get someone else out a moment ago to be charged another lb100 for nothing. Any Advice would be appreciated
If wet get kerosene feul supply...
Answers:    The first article the chap should hold checked is the primary sensor,it does sound resembling thats the problem.If they have renewed this constituent then its a failure on the pcb.
The c23 and c27 are contract boilers,cheap and sparse in components,however they do hold a fault diagnosis indicator on the front panel.When the boiler fail on you,look at the two lights on the left mitt side of the front panel,they will flash in a particular order which can be checked contained by the manual to identify the reprimand.
Phone Alpha and request they send out an agent within your area.01732 783000.
Would it be possible for me to fix...
Check the wet pressure, there should be a guage on the front panel, if this is low it could lead to the problems you are experiencing, if it is low you should have a filler loop already fitted, simplu sympathetic the valve and see the pressure until it reached the green zone.