I don't think its a Viburnum - they have 5 petalled flowers, and this shrub has four petalled ones. Having said that, so far, I've no idea what it actually is, still looking...

UPDATE: I think its an Edgeworthia, maybe Edgeworthia chrysantha, possibly 'Red Dragon' because most of them have yellow to cream flowers. Not entirely hardy, tolerates down to -5 deg C, needs a sheltered spot.

i'd go for Edgeworthia too. its a lovely shrub with a citrus scent.

Thank you both so much....I was very impressed by the shrub and would love to grow it in a large pot shelterd and in the sun.

Will likely be more vulnerable to cold in a pot though, so you'd need to take extra precautions in a cold winter - like insulating the pot, etc, eventually, but while its in a smaller pot and easy to move, perhaps putting in a cold greenhouse or somewhere similar.

My edgeworthia chrysantha is now ten years old, having come through the bad winter of 2010/1. It is planted in a sheltered, west facing position.

yea, but you've created a great micro climate, Andrewr! Is yours planted in the ground,not in a pot?

Thank you for all your replies and information. I may treat myself to a plant and put it in a pot moving it into a greenhouse in the winter. I found it just so beautiful and almost irresistable. I know it blooms early spring. Worth the risk.

Yes Bamboo, it's planted in the ground. Sheltered from the east by a fence, but a bit open to the north.

It is lovely.