If I break the contract after the 4 month break up clause am I still entitled to my deposit back? (The landlord has sold the house but won’t tell me a date to move out)
Depending on what’s in your contract, the landlord is still required to give you the min 2 months notice to end the tenancy. You should check the section in your contract about terminating the tenancy / invoking the break clause. Assuming you provide the required notice and the usual tenancy termination requirements are met, such as ensuring the condition of the property is the same as when you moved in, all utility bills settled etc, I can’t see any reason why you would not get your deposit back.
If you have complied fully with the terms of any break clause and the break clause does what you think it does, then yes, the landlord would have to refund your deposit provided there is no damage or arrears.
If you want more certainty, reproduce the break clause here.