Fruitless pear tree

I have planted conference pear tree which is in it's second year on my plot, this year it has a few pears on it. I also inherited from the previous plot owner another tree which has similar leaves to the conference tree, it had white flowers a few weeks ago but now only has green leaves but no fruit, I have heard of decorative pear trees that bear no fruit, I was planning to give it another year to see if it produced fruit, my question is how long does it take a pear tree to produce it's first fruit, the tree in question has been there at least three years.

Mum is right ,my cherry tree lost 80% fruits due to this year's late frost, a lot of people had the same problem here.

Trouble is we had some late frosts this year, that could have damaged the flowers on the later flowering tree 

http://www.fruitnet.com/fpj/article/172058/apple-growers-despondent-after-frosts-hit-crops

Generally, if you get flowers you get fruit, unless the weather is bad at/just after flowering.

All the pear trees I planted over the last few years have given good fruit every year BUT the pear tree that was here when I bought the plot is by far the best tasting, biggest fruit and biggest year BUT BUT BUT only every second year. Regular as clockwork one year nothing, one year a feast. I dont know the variety or a reason why. There are plenty of pollinators around and I don't treat it any different any year.
Luckily this year is the feast year and is looking good.

As MoS says - late frosts were definitely a problem this year. Your pear tree is still very young. How old is your Victoria? I'm fairly sure they are generally one of the most reliable to fruit, but we had two nights of killer frosts in late April this year and afterwards I watched all the little fruits on all my trees turn black and drop off one by one.
Very disheartening, but I imagine they'll come back even stronger next year after the enforced rest!

I have had my pair tree for around 3-4 years and it has had few pairs on until this year. Now it is loaded so that the branches are bending.
Perhaps yours just needs time.

I can also confirm that the first two years of my dwarf conference had no pears, but this year (3rd) I had a good number and decent size pears for the first time. Apart from that it does depend on fruit tress just when the blossoms appear in relation to weather and pollinators.