need a low cost clean b&b in london

please define low cost - £50, £100, £150??

Hi, I see this is your first post. I recommend Googling "Rick Steves forum London hotel" or something similar and read through older threads on this topic if you haven't already because your question is one of the most frequently asked on the forum. A lot of good information available in past posts.
My stock answer is http://www.number63.co.uk/ but don't tell the world or else they'll raise the rates on me! ;)
Have a good trip!

Thanks for the response. I should have been more specific. I'm looking for something in the 70 GBP range, I room, I person, like en suite but not absolutely required. I'm a fit older woman who will only be in London for one day en route to Amsterdam and will return to London for a few days in May before traveling home. Hope this info is helpful. I made a reservation at the Stanley House near Victoria as I had stayed there several years ago and found it adequate but there may be a better choice. I enjoyed the full English breakfast that they provided and it was close enough to the station that I could easily walk.

Have a look at the Ridgemount Hotel on Gower Street. It is not expensive, family run, close to British Museum and the John Soanes. Good calorie laden breakfast is included.