I have a baxi 552 back boiler with a 4 burner radiant fire I have just bought a baxi bermuda vp3 fire When i called my local corgi registered installer about swapping over the fires he said i would have to get a supply pipe from the boiler to the fire I got the pipe but it looks a much smaller diameter to the original pipe which looks the same diameter as the connection to the vp3 fire can anyone tell me if this is correct about the pipe as the fitter is due to come out next week when he returns of holiday and i was wanting to have the part for him to just do the swap