boiler broken

Other

Tenant knocked on my door 9pm last night saying he had no heating/hot water. I went to check if this was just because of low pressure - but I couldn't sort the problen.
An engineer went round this morning, but tenant was out - despite him telling me he would be home all morning.
Now getting constant txts and calls demanding action and problem to be sorted today.
What are my obligations now - i have arranged for engineer to call again on Monday - I also phoned British Gas and the first time they could attend a call out is Tues am !