The F24 boiler in my flat cuts out and stops after an hour or two...will not stay on properly and .makes loud whooshing noises before it cuts out..scary...has been serviced about a month ago, but hasn't worked well for 6 months. Gas engineer and landlord haven't a clue what it is...any ideas please...I'm really cold and am awake at night because there is no heat...Thank you!

kj, November 2012