boiler 2.5a fuse keeps blowing on start up

[siros80]

Hello Can any one help me out,I I have a Worcester Greenstar 28i junior boiler and the 2.5a fuse keeps blowing on start up. Iv replaced it three times but it only last about 5 seconds, then it blows what do you think it could be.The water pressure was down the day before the problem started, I just re fiulled it back to one bar. What can I do, and who would be the best trade to call if you think its not a DIY. Iv been reading older post that say it sounds like the pump , how would I test this or any thing else? many thanks

 

[mysteryman]

You are likely to need a professional central heating man for this.