https://www.gov.uk/tax-foreign-income
You may need to pay UK Income Tax on your foreign income, such as:
wages if you work abroad
foreign investment income, for example dividends and savings interest
rental income on overseas property
income from pensions held overseas
Most likely :
Pay Canada tax as before
report rental income to UK
claim foreign tax paid (credit) to reduce UK tax
Eg. Canada Tax paid 1,000
UK Tax 1,200 payable minus $1,000
Then you pay $200.
If UK tax is $1,000 or less, you don't have to pay any additional tax.
Not sure about the excess tax paid to Canada if UK tax is lower