Hi, I've been having heating problems recently where the heating wasn't always coming on. I have a Worcester Bosch condensing boiler which has recently been serviced, and a Lifestyle LP241 timer. The timer lets me set 2 times for each hot water and central heating. What I've found is happening is that the first heating is coming on, but not always the second. Unfortunately I can't even manually turn it on when it stops working. Hot water is always available. A plumber has been and he has replaced the 3-way valve and switch for me, as he said that would be the problem (to be fair, the valve pin was broken). It still hasn't fixed it though. The new switch has a manual override but even that doesn't work when it won't come on. The plumber came back to check, and lo and behold, the heating was working fine and would come on on demand. Later that day, I couldn't get it on. But he told my wife that we should replace the timer or get a thermostat fitted. This doesn't feel right to me, because when I try to manually switch it the pump starts making noise. But all 3 pipes connected to the actuator are cold to the touch. Could it really be that or is something else likely to be happening? At the moment I'm having to leave the heating on all day and just control the thermostatic valves in the radiators.