Baxi Combi 133 HE Plus problems?

My girlfriend has one of these boilers which is 2-3 years old in a new build property. The timer unit on the boiler doesnt work (hasnt worked for the last year) so she can't have the central heating come on in the morning/evening at preset times. Several of the radiators are lukewarm at best.

She has been told that she needs to repressurise the system but is currently missing the relevant pipe (the system filling loop).

My questions are:
- do these boilers usually come with a guarantee?
- how expensive will it be to replace the timer unit?
- if she bleeds the radiators will this affect the boiler pressure (she is unable to repressure the system until she gets a replacement system filling loop).

Thanks in advance for any advice