This reply assumes: You are currently US resident, citizen, and domicile, and by moving to the UK you will not be aquiring or re-aaquiring a UK domicile of choice or origin.
1) If you meet the definition of tax-resident in the UK for a full calendar year at any point in your two-year stay, you will be able to claim Bona Fide Residency, which doesn't have the 330 day limit.
2) You can take tax credits for UK tax paid against your US tax.
3) You may have to pay UK tax on your earnings. Get professional UK tax advice to determine whether or not you will pay UK tax, and if so, if the treaty will allow your workdays to be 100% UK (even if performed in the US).
4) If the treaty turns your US workdays into UK, then you also do this on the US return, making a treaty claim.
5) In any event, you can take deductions for the cost of renting out your condo against your condo rental income.
6) You may also be able to claim the costs of renting in the UK as a deduction, if you qualify under the Bona Fide Residency test.
7) You may also be able to claim these as a deduction against any UK tax you might owe, making the money spent on your UK housing 100% tax-free (a double-dip).
Your condo rental income will not be taxed in the UK provided you do not remit it to the UK.
I strongly urge you to seek professional US and UK tax advice in the area of treaty re-sourcing and treaty residence. You may luck out and with minor changes to your plans end up in a nearly tax-free living situation; or conversly you could pay big dollops of tax without planning. The savings is in the 1,000's of dollars, it's well worth whatever the advice will run you.
IRS Circular 230 Disclosure: To ensure compliance with requirements imposed by the U.S. Internal Revenue Service, we inform you that any tax advice contained in this posting (including any attachments) was not intended or written to be used, and cannot be used, by any taxpayer for the purpose of (1) avoiding tax-related penalties under the U.S. Internal Revenue Code or (2) promoting, marketing or recommending to another party any tax-related matters addressed herein.