Hi people, I go round my in-laws once a week and there house is so very cold. they never turn there heating on cos they have a control unit which has 2 options. HW or HW/CH. If there require just the CH on, then they cant do it. Can i just change the program clock for once which can. Its a BAXI SOLO system boiler. There is one 28mm pipe entering from the bottom of the boiler, and one 28mm pipe leaving from the top. When system is on they are both hot. Any Help on this matter please........