Hi, my parents have a promax combi 28 he plus a boiler. yesterday they came home to no hot water. the heating is working and we have cold water coming out of the cold water tap but nothing is coming out of the hot water tap. we had a british gas engineer out today and she advised that it was a frozen pipe. the pressure on the boiler keeps fluctuating too...and was sitting in the red last night. the engingeer didn't seem too bothered by that....should we be??? also, the domestic hot water indicator on the boiler doesn't ever light up....even when we try to turn the hot water tap on...should it?? the pipe doesn't seem lagged properly so dad's done it today but we're still not sure if it's definitely a frozen pipe. sorry to go on but if anyone could help, that would be great. Thanks