My heating system packed up just as the cold spell was beginning. Despite three visits from my trusted installer, Tony, the fault couldn't be traced. It didn't seem to be the boiler or the thermostat, a new pump was fitted, a new valve and still the heating came on at random times for an hour or two, usually in the middle of the night. Finally, all options exhausted, Tony decided to call in a Veissman engineer. Gareth was brilliant. I was his last call of the day. He determined, after a thorough examination, that it wasn't the boiler, and although it was past his allocated time slot, he stayed on and tested other components of the system - and finally found in fault in the new valve that that been fitted. It was replaced the next day and everything is working perfectly. So two big brownie points for Veissman - the problem wasn't the boiler, which was working perfectly, and the engineer Gareth acted helpfully and successfully to find the real fault.