entry to abandoned premises

[LucyGirl]

My tenants have left the house they rented without paying rent and without notice or returning the keys. We won in court for nonpayment by default and now it will take 3-4 weeks for the marshall to "evict" the tenants and then we will be able to have the property back. My concern is protecting my property. I was told by my lawyers if I entered the empty house before the marshall executes the eviction it would be unlawful entry. I would like to enter to maintain the heating system so the pipes do not feeze thus preventing damage to my investment. Why can't I be allowed to protect my property? How can I get access to my house to secure the premises?