gas boiler tripping

Hi all minor problem with the heating system at home.
Hope someone on here can be of help.
I have gas fired central heating around 10 years old.
Heating works fine in relatively warm weather but now that the nights have turned chilly the boiler has to be reset before starting then it works fine. It tries to start and turns off then i hit the reset button and it starts no problem
The only real drawback with this is that I can't set it on timer as it wont start without being manually reset.
I bought my home 3 years ago and this problem has been ongoing ever since, while getting it serviced I asked the gas man and he wasnt much help said I'd have to get another call out.
So here is my next port of call any suggestions/advice gratefully accepted.

What is the boiler make/model

is the fault there after the boiler shuts down from the last run period?
sounds like maybe pump or fan overrun is not working and the boiler goes out on high limit at the end of a run cycle

make sure the boiler has a permanent live if not this may cause this issue

The boiler is Vokera Mynute 14e.
It works fine once its been reset, if on timer it turns on and off perfectly.
It seems only when its cold that its a problem.
Thanks DGOBS

I would be thinking of either changing the thermister and/or the high limit stat. But there is other reasons for this kind of problem such as pcb not calling for fan/pump overun and the like. What area are you in as I may be able to give u a contact number for a decent tecnician in ur area

I am in Cork city and would appreciate a number sorry for my infrequent replies but my wireless internet is terrible.
Thanks

sorry have no cork numbers
Try ring Vokera direct