NNN maintenance obligations

[Andrew Shrigley]

I have recently leased out my commercial property. The lease states:

1. Landlord agrees to make all necessary repairs to structural portions of the Premises, including the roof, exterior walls, foundation, and exterior sewer line.

When preforming agreed upon repairs all the toilets were flushing and operating, not clogging.
The tenant has been occupying the building for two months and emailed me yesterday saying that all the toilets were clogging. I recommend they call a rooter service to have lines snaked. They argue that it is my responsibility for bill because of the scale build up and sludge. It's under $500 so not an extreme expense but I argue that it falls under the NNN maintenance purview, responsibility of the tenant. There are no breaks in line just build up.
it’s two months into a 39month term. I don’t want to create riffs in our landlord/tenant relationship but I also don’t want to pay for it.

In this case, who should be responsible?

All comments and opinions on this are welcomed and appreciated. Thanks!

[Nathan Gesner]

Quote from @Andrew Shrigley:

Technically, you are correct that this is a tenant responsibility. However, they have a valid point that two months use isn't enough time for them to create the clog unless they've really abused it by flushing things they shouldn't.

When using a NNN lease, I recommend a full service before handing it over to the renter. This means flushing the sewer lines, servicing the HVAC, etc. Make sure everything is 100% with receipts to back it up, then make the renter take responsibility.

In this case, I would probably service the line just to be sure. If the plumber finds any evidence of abuse, charge the renter. I would also have a conversation with the renter and make sure they are 100% clear about their responsibilities going forward, even if something happens next week.