Can I convert my existing boiler to use wood pellets?

Conversion kits for oil-fired boilers (and some other types) can be found abroad; for example Ariterm's burner unit. Besides a replacement burner unit, you will need to install a pellet store and handling mechanism (typically an augur to screw the pellets from the store to the burner). But at present, no one is marketing the conversion burner units in the UK, so your only options are a dedicated wood pellet boiler or room heater.

If you are interested in a conversion kit, try asking the pellet-boiler installers. You never know, one of them may have started importing one by then. And failing that, at least you will have let them know there is a market.