Hi Julie,
sounds like you know little or nothing of gas boilers by your question (no offence) but a boiler going to lockout condition does so due to a fault having occured in the boiler, what it sees as an unsafe condition, so it locksout for intervention, if when you reset and fire again, the lockout repeats it will be best to get a serviceman out the check and repair the problem.
T, June 2008
