Boiler was playing up, water was warming up for domestic usage but the radiator remained cold. Thinking the 20 year old boiler had its day I was prepared that I was facing a hefty bill for a replacement. LR plumbers checked the appliance and diagnosed that a part needed replaced. Divert valve or something like that replaced the following day and boiler working perfectly. Charged a reasonable fee but what I like was that he arrived on time at a time that was convenient to me.
Will definitely use again.