Blocked toilet - blockage location?!

Escapees

So, water fills the toilet bowl when flushed but then slowly drains to a much lower than normal level and makes gulping noises every now and then... Am I right then in assuming the issue is in the sewer line or at the tank, and not at the toilet itself?

Have tried plunging till the cows come home and also threw in some caustic soda mixture but no improvement. Don't have an auger so stuck some coat hanger up from the bottom of the bowl just in case but there doesn't seem to be any blockage there.

Note that the setup here is old and shoddy and there doesn't appear to be any vent in the line or inspection points. Also, removing the toilet is going to be a pain because of the setup so I don't want to go down this road unless there is a real chance of the blockage being there.

It's the low water level thing that makes me think the blockage can't be at the toilet?

K.Flyer

Is the toilet upstairs or downstairs?

Escapees

K.Flyer wrote: »

Is the toilet upstairs or downstairs?

Only toilet, downstairs...

K.Flyer

Go outside, there should be some black plastic drain covers (app. 1ft x 1ft) at the front, back or side if the house. If you lift them up you may find one of them is blocked or full to the top, ordinarily they all should be clear and empty.

Escapees

K.Flyer wrote: »

Go outside, there should be some black plastic drain covers (app. 1ft x 1ft) at the front, back or side if the house. If you lift them up you may find one of them is blocked or full to the top, ordinarily they all should be clear and empty.

Like I said, an 'old and shoddy' setup here, so no drain covers etc. Just one long run of sewer pipe, some of which is buried.

moonshadow

Have a look in the septic tank, more likely than not if its that old it's full to the exit point to the soak hole , if so it needs emptying cost you about 250€ to do so.
Bad point is if it's overflowed down th soak hole it'll be blocked with sludge and will need emptying more often .