Glow Worm Ultimate Central Heating Boiler which one???

I have had this fitted now for about 10 years and it has been brilliant until the last couple of years but I am not complaining. It has only had a new solinoid, new pilot jet all fitted by a Corgi engineer.The pump failed last week the engineer is coming to replace that today, he also mentioned the fan is a little noisy but a little wd40 worked wonders but I would feel better having a new fan. It looks relatively simple to do having no gas connections and only 2 spade connections and 2 rubber pipe connections.I reckon I can do that myself. I have seen fans on the internet quoting ultimate 30-40-50-60 and they all look slightly different.Some show a fan on the top, some don't. The installation book quotes 30-40-50-60- models but doesn't actually show which model my boiler is. I have looked on the casing and can find nothng relating to the model. Any advice would be helpful and a rough estimate of cost would also be helpful. Ons last question there is a Potterton National Advertising campaign at the moment on the Gold HE Combi range. Prices seem brilliant,24HE £629,28he £689, 33HE 3749 and I am wondering if its perhaps time to change to a Combi but have no idea how much it would cost to fit..
tHANKS FOR YOUR HELP.

I would feel better having a new fan. It looks relatively simple to do having no gas connections and only 2 spade connections and 2 rubber pipe connections.I reckon I can do that myself.

Click to expand...

it's also part of the flue system

Why not get the engineer who is coming to change your pump to fit a new fan while he is there?? it would save a call-out charge would it not, and your engineer would be able to kill two birdys with one stone!!
(everyones a winner)

P.S. as has been said a flue fan is part of the flue and not a DIY job , the last ultimate fan i had to fit was a bit of a B*****d TBH

Thanks for your comments,, Engineer fitted new pump, took 15 minutes, everything working fine.
I bought a new fan fitted it myself, took 15 minutes, as it happened the engineer left one of his tools behind, when he came back he checked that what I had done was in order,