From your facts, it's hard to say whether your trailer would be considered a single family home or not. "Mobile homes" being rented by tenants are considered "dwelling units" for purposes of the FL Residential Landlord & Tenant Act (FL Statute Chapter 83, Part 2). However, a trailer may or may not be a mobile home & may instead be considered a motor vehicle in some cases. Also, the Act does not make clear whether a mobile home rented by a tenant is considered a "single family home." Unfortunately, while the maintenance statute, FL Statute 83.51, references single family homes, that term is not defined.
If we assume that your trailer is a mobile home covered by the Act & that it is indeed a single family home as well, you should review your lease to see what it says about your duties to the tenants &/or the tenants' duties as to maintenance & upkeep of the trailer. If you do fall under FL Statute 83.51, it's important to remember the lease can modify the provisions of that statute, ie, it may turn some of the maintenance duties over to the tenant & take them out of the landlord's hands.
If that is the case & it's in the lease, the tenants could actually be responsible for refilling the gas tank themselves. You DID mention that you told them they would have to fill the gas tank. The problem is, if that's not in writing in the lease, you will have a "he said/she said" situation on your hands. The other problem you may have if it's not in writing is that your lease may very well say that it is the entire agreement between the parties - if so, then the tenants may argue that their filling the gas tank was not part of your lease agreement.
Returning to FL Statute 83.51 on its face, subsection (1) pertains to a single family home or duplex - it states that the landlord must comply with all applicable building, housing, & health codes. If your trailer were to be considered a single family home & your lease did not modify your responsibilities as the landlord, then you would need to find out whether your local housing & health codes require you to provide heat.
However, under subsection (2), a landlord of a property other than a single family home or duplex IS responsible for providing heat, running water, & hot water to the tenant at all times. Subsection (2) also can be modified in writing, so if your trailer is not considered a single family home & you fall under FS 83.51(2), your lease may specify the tenants are responsible for heat, running water, &/or hot water. However, if the lease does not say this, then we're right back to the same problems discussed above.
Finally, you do not say why you gave them a 7-Day Notice, other than you "have had problems with them ever since they moved in." Based on that info alone, it's impossible to say whether you were justified in giving them a 7-Day Notice. Simply disliking the tenants or considering them a nuisance for making numerous maintenance requests does not entitle a landlord to try to evict them.
It may be in your best interest to take your lease to a private attorney who can review it with you & get a better understanding of what you're trying to explain in your question here. They should also be better able to tell you if you have a case for evicting the tenants before their lease expires & if so, what your most successful arguments in that regard would be. Hopefully they can also help you determine whether your trailer falls under the "mobile home" &/or "single family home" categories of the FL Residential Landlord & Tenant Act for purposes of interpreting how the Act applies to your situation. Good luck to you.
The above information is not comprehensive & is intended as a starting point for educational purposes only. It does not create an attorney-client relationship with the author. It should not be used as a substitute for legal advice & counsel from a private attorney who can review your situation in detail & help you determine a course of action based