Rafal Kaczynski
Hello David. Unvented Hot Water Cylinders have to be service every 12 month . Full service of Unvented Hot Water Cylinder can be carry out only by qualified engineer who should have a card on him for this systems. It should not take longer than 1.5-2 hrs and is based on visual and manual inspection of PRV and pressure limiting valve, terminal fittings( flow regulator) suplementary bonding and current device( fuse) anode if has fitted one, all electrical connections removal and cleaning if neccesary line strainer, check on expansion vessel pressure and recharging if neccesary , tundish and discharge pipes, thermostats .( check for correct temperature settings ) the person who is going to carry out service will ask for manual as with those kind of cylinders service should be carry out by manufacture proceduders. I hope all this can help. Kind regards Rafal
