If no GD, any blockage service call will certainly be tenant responsibility to pay.

There are openings in the upper west exterior walls where electrical conduit was removed.10.The stucco in these areas has not been repaired to prevent moisture penetration and deterioration.11.The front unit has issues flushing the toilet, which was confirmed with a tenant, so camera scoping of the drain pipes was performed that revealed damages and blockages in the pipes.12.Deferred maintenance on multiple items: cracks around windows and pipes, gas pipes are not supported, pilot lights in heater units were not lit, a water heater unit has no ventilation.I hired a plumber to scope the pipes (please see his report in the invoice attached and photos); a roofing company was hired to assess the damage to the roof above the middle unit only (please see proposed work sheet); a general contractor has inspected the settlement of the wall in the second unit due to the damaged frame.

Currently there is no blockage but when it rains there is almost flooding every time.

If you find blockage they probably contributed.

(Hopefully if you don't use the CAR lease then your lease has a similar clause that holds the tenant responsible for toilet/plumbing clogs/blockages that they cause.)So, as you can see, there's far too many variables to give you a simple answer as to when to authorize the afterhours service calls and when not to. 

Gated community, 3/3/2car 1512sf built 2006 Monthly costs Hoa 66, insurance 57, management 89, taxes 58 rents for $1125 $212k value = $170k loan @ your 4.612% = $873 total $1143 (minus $18/mo)In the last year I had to paint the trim ($500) and fix clothes washer ($237)#2 preferred single story model, not Gated community, 3/2/3 car 1456sf built 1993Monthly costs Hoa 0, insurance 44, management 90, taxes 64 rents for $1125 $250k value = $200k loan @ your 4.612% = $1027 total  (minus $100/mo)In the last 2 year I have had zero repairs #3 non-Gated community, 3/3/2car 2200sf built 2007Monthly costs Hoa 57, insurance 46, management 98, taxes 74 rents for $1375 $264k value = $210k loan @ your 4.612% = $1078 total $1353  (plus $22/mo)In the last year I had to replace the stove ($590) and fix a sewer line blockage ($125)In north Las Vegas sewer is included in garbage,recycling/water bill from the city. in Las Vegas I bill the tenant for sewer per the lease (about $250/year)

Roto Rooter ran a pipe with a camera attached and found no damage or blockage in the sewer line.When the bank comes back with financing approval we will then be in the clear to start pumping out water and drying out the crawl space.

If you have this type of set up at this house, then drain blockage is a possibility.

If you have old cast iron or galvanised drain lines, you will also have more problems with low-flow toilets as the inside surfaces of these pipes are more likely to not be smooth - or have partial blockages.

This can be rectified with the adjustment of pilot flame, unless it is caused by blockages in the burner tube orifices.