We are having the bubbling toilet problem also... We do have septic and it was full, had it emptied. My husband took up the toilet, snaked from there outside and then snaked from the outside to the septic tank and then snaked a vent above the laundry room. We have another vent on the very top of our roof also. Does this need to be snaked out as well. Thank you for your help and time in this matter. Oh after we emptied the tank the bubbling stopped for 1 week but started again.

Sounds like you may have a drain field issue. Check to tank when water is running and the bubbling is occurring to make sure the water level is not above the intake and outlet pipe of the tank. If it is, and you just had it pumped, you have a plugged or saturated drain field. Doesn't sound like a vent issue at this point, but a backup problem.

I agree with Lee on this one. It sounds more like a saturated drainfield.

We are having the bubbling toilet problem Bubbles indicate a blockage not a vent problem.

after we emptied the tank the bubbling stopped for 1 week This nailed it down. The bubbling stopped while the tank was filling. When it got full the drainfield could no longer accept what the tank sends it so you're back to square one.
The solution would be to move the drainfield. Good luck, Tom

Not so sure guys. Let's start with how a septic works. A functioning tank is always full, it then overflows at the very top out into the field tiles. If the field is saturated then no liquid can over flow and the tank would back up, not just bubbles but actual sewage. Could be that the sewer gas was venting into the tank, path of least resistance until the tank filled and had no more space for sewer gas. I think there is still a venting isue. OPs original question is with two vents does the other one have to be snaked? Quick answer , yes

Good rebuttal Bob! But you're making a big leap of faith here, You're assuming the drainfield's completely and totally blocked up and won't let any water peculate.into the soil. If the drainfield was only partly clogged it would still give back pressure, (bubbling) and still allow the water to drain. Let me call your attention to,
The bubbling stopped while the tank was filling. When it got full the drainfield could no longer accept what the tank sends it so you're back to square one. I still say, The solution would be to move the drainfield. Good luck, Tom

That could be a $20K solution so I'd do more investigation before doing that. When a drain field is even partially blocked the absorption rate is so low that the tank will fill and back up even for just a short time. OP has not said the house drains ever back up. The OP needs to open the tank and observe what happens when a large discharge is done like a filled bath tub. OP probably also should be working with a sewer contractor who knows about septic systems.

Bob. What about "The bubbling stopped while the tank was filling." wouldn't that indicate the fault lay downstream from the tank? You said,
I think there is still a venting isue. OPs original question is with two vents does the other one have to be snaked? Quick answer , yes And you still think this is a blocked vent?
Here's my take, Bubbles indicate back pressure and a clog. Gurgles occur when one fixture is attempting to vent through another fixtures trap. And that indicates a blocked vent. Agree or disagree? If you agree with me you've just shot your argument down. Cheers, Tom

I think we can tell the difference between a gurgle and a bubble but not so sure an OP can always be trusted to use the right terminology. If it is not a vent issue then it's a clog by your thinking. So how come the OP never mentions any backup? I just think that at this point a $20K replacement field is a big step to take on a recommendation over the internet with no site inspection. The OP needs to get an on-site contractor out there to see what's up, someone whgo knows septic systems and is not a crook

The sentence that hangs me up is,
The bubbling stopped while the tank was filling. If this were a blocked vent this wouldn't happen. It would gurgle no matter if the septic tank was full or not. All we can go on is the OPs complaint, You're attempting to second guess him. That isn't like you. What is it about this post that makes it different? Sounds simple to me. It could possibly be that there's a blockage in the line to the drainfield but my bet's still on the drainfield. Regards. Tom

I deal with lots of septic issues at the lake house area west of Rockford. Maybe I am getting old but too many people have said to me bubble and it turned out gurgle. OK say I join you with the clogged line or saturated field, how come no backups? No mention of a slow drain either. I would think we'd be seeing both by now, don't you? Here is my thinking on the sentence that hangs you up. Venting follows the path of least resistance, are you OK with that? If the vent were clear it would go to the stack. If the stack were clogged venting looks for an easy path. In this case the tank was empty except for about 1000 gallons of air in a not air tight conntainer. I think the tank would act like a vent rather than the standing water in traps and toilets. Maybe the OP should tell us what happens when they flush the bubbling toilet and if there are other toilets that do not bubble.

Well that's a fresh take on thus problem. "The Tank did it" You are now assuming that ALL the vents are clogged and the system's venting through the septic tank. Why don't we just wait and see how the OP resolves this. OK? Enjoy your Sunday. Tom

Could be wrong but septic systems are funny ducks. Thanks and have a great weekend.