You cannot force the tenant to pay the gas bill, and the Landlord and Tenant Board does not acknowledge potential damage as grounds to terminate a tenancy. So, unless the tenant moves out you are faced with the following choices. You can either:

1 – Approach the tenant about agreeing to change the terms of the rental agreement to include gas and possibly hydro in the rent, in exchange for an increase in rent to reflect the average extra charge that you will incur, once the gas bills go into your name;

2 – Speak to the utility provider about making temporary payments to keep the utilities on. This may be difficult due to privacy law restrictions, and they may want the tenant to be involved in any changes.

3 – Switch the bill to your name anyway, and file an application with the LTB. As of September 1, 2021, landlords can file an application for failure to comply with utility costs with the LTB. The prescribed form is available on the LTB website at http://tribunalsontario.ca/ltb/forms/.

Either of these scenarios will hopefully avoid a potential situation involving burst pipes, flood, insurance claims and so forth. Otherwise, the tenant may agree to vacate very soon, and if so, you should try to get a termination agreement signed (From N11). All the forms are available from the Landlord and Tenant Board website – http://tribunalsontario.ca/ltb/forms/.