U.K. and Ireland - Accomodation or Hotel in Central London

Have been staying with friends who now have a lovely, but very sick child, so need to find a cheap hotel. Any suggestions for good but not pricey?

This is a fairly pointless thread, frankly, without any idea of what you call cheap and what you call good. Or indeed what you call Central London.

Cheap options:
easyhotel
Tune Hotels
Z Hotel (thezhotels.com)

Still pretty cheap:
Premier Inn
Travelodge
Ibis

Between July and September, Imperial College lets out its student rooms at good rates. LSE does the same.

Remember that Radisson and Park Inn are offering 50k / 44k Carlson bonus points at the moment for a stay, so if you are willing to hotel hop across various accounts you could earn enough points for many free stays at some point in the future.

If there's avail you can always try the F&F rate for the Radisson brands.

If there's avail you can always try the F&F rate for the Radisson brands.

... Or indeed the Holiday Inn brands.

The 2 4 1 rate with Priority Club can get you a Holiday Inn Express very cheaply.