Hi, I currently have an Alpha HE CB33 combi boiler. I can only get hot water when the heating is on and turned up high. My gas engineer friend confirmed that the diverter valve needs replacing. There is also an issue with the pressure. I have found a couple of small leaks on two valves. I assume this can make a difference. The needle on the pressure gauge wobbles from time to time. Im told this is because the expansion vessel is on the way out? So my question is, with the diverter valve and expansion vessel looking like they need replacing, i might as well invest in a new boiler for £600 instead of paying out £300 odd for parts? the boiler is 8 years old. Its not that i don't trust my mate but i could do with a couple of other opinions. Thanks in advance.