plumbing expenses 4 months after tenant moves out

[Brandon McCombs]

This is probably a question with an obvious 'no' answer but I asked tenants to vacate by end of Oct 2020. They did. I didn't get a new tenant until just a few weeks ago. By law I had mailed the previous tenants the security deposit letter and expenses deducted from it within 30 days of their vacating. But recently there were some plumbing problems reported by the new tenant that have necessitated a plumber. The damages to the unit exceeded the security deposit amount but they have agreed to pay the excess willingly for which they signed a payment agreement with me and are up-to-date with their payments. I suppose the cost is not something that can be retroactively billed back to the tenants? The property is in Ohio.

Plumber eventually snaked the toilet and ended up having to remove the toilet from the drain to pull out a kid's extra large toddler plastic blocks so it's definitely not the current tenant's item (separated woman in her 50s who lives alone in the unit with no family visiting). It's the biggest block so it's about 4" long and 1" wide or so, stuck in the curve part of the toilet. Not sure what the final bill will be but probably $200+, at least $150.