Pressure loss in central heating system

Hello, I'm hoping that someone can provide some advice. We recently (November) had a new boiler fitted, an Alpha CB25HE. Subsequent to this, we've had a problem with the pressure in the CH system dropping rapidly, and having to be topped off maybe 3-4 times a day. Obviously, I know this is NOT a good thing. We've had an engineer out, whose opinion was, unsurprisingly, "you've got a leak, mate". There doesn't appear to be anything wrong with the the pressure vessel, as we've, not placcy bagged, but stuck tissue paper in the pipe (don't laugh, that was the engineer's idea) and that's stayed put and is bone dry. We've topped up the system and bled the radiators, but that hasn't helped. The engineer states that we have to pull up most of the floor to locate the leak. I'm REALLY reluctant to do that, since we've just had quite a lot of the flooring re-done, and I don't want to completely trash the oak floorboards in the rest. Scouring the forum, I noted that one poster stated that there are firms that can locate a leak through things like IR and gas diffusion, albeit at a cost. Is anyone familiar with such companies, please? Could someone give me details? Many thanks.

Nick

You have my sympathy Nick, we have exactly the same problem. We have concrete floors and the Gas Board Engineer says the only way to find the leak is to dig up the floors. We've decided to have surface pipes fitted, and have someone coming next week to give us a price.
Like you, we've had new carpets fitted, so we're not very happy.

could try hiring a infra red camera to locate the leak,

http://www.hss.com/g/25910/Infra_Red_Camera.html


or contact MUNTERS they locate with thermal imaging cameras

may be cheaper

PS just found this place

http://www.thermalimaging.co.uk/sales-and-rentals/index.htm

Thanks, sickas, and that's a good suggestion, corgiman, I'll look into that immediately. Much appreciated!

I've actually been looking at getting hold of a borescope and using that to try finding the leak. Might avoid actually ripping up the floor that way.