Red warning light on. toilet gurgling. what do i do

Ensure all your additional rough in plumbing is capped, and toilets or sinks that are not used for long periods of time , sometimes p traps may dry up allowing sewer gasses to enter the home so use them once in a while or fill with water once in a while ,same with floor drains. If that isn't it check that you have them installed.

Your sewer vent may be clogged, or if you are in the northern climates, frosted shut. When you flush the toilet the water displaces the air in the drain piping. The vent gives the air somewhere to go. If the vent is plugged the dispaced air forces it's way out through the path of least resistance( the lower toilet in this case).Pour some hot water down the vent where it comes through the roof to thaw it out.or run a snake down the vent. Hope this helps.

If water is backing up into the tub then you have clog downstream from that bathroom group. If water backs up when you ran water in the rest of the house then you have a clogged sewer service. With either case the house drain and / or sewer drain will need to be snaked. Most of the time it will be the sewer drain.

It sounds like a vent problem.
On top of each house is a vent stack.
There should be a vent stack above each toilet, and above kitchen sink.
Look for pipes sticking out of roof.
These pipes are open to the sewer line.
When you run a column of water down a drain, the vent stack lets air flow in front of and behind the column of water.
This air flow prevents the gurgling sound.
The gurgling sound is the drain water pushing air in front of it because of a clogged vent.
If you have a two story house, there are vents that run between floors to prevent the air flow from gurgling or bubbling sewer air into each drain as water column moves down pipe.

http://www.bradyinspects.com/plumbing-vents.html
http://chestofbooks.com/home-improvement/construction/plumbing/Standard-Practical/Venting-Part-3.html

Look for bird nest over vent pipe on top of house.
Run a snake down into pipe from roof and see if the is a stoppage.
You many need to call plumber to track down each vent and the cause.
For example if there are quick-vents installed inside a wall and the quick vent is no longer working.

You can also take advantage of fixya phone support.
Fixya expert will walk you through the steps for a price.

there is no air release. the vent must be clogged somewhere. you can take a hose up there and see if it drains all the way or floods over. since the tub drain has a trap and the toilet itself is a trap, there has to bee a good amount of air pressure coming up without a release. i would say an obstruction. possibly at the junction of the main and the vent.

We invited Roto Rooter out and he had it snaked out in about 2 minutes flat! No more problems for now. I think we need to purchase one of those tools!

sounds like you need septic tank pumped out. or there is a clog in main line if city sewer. hope this helps. duane.

it could be your main sewer line from your house to the city main is starting to clogg up, if your tub or sinks or even floor drains are doing it at the same time you probably want to get that line cleaned out before it cloggs completely

Start with the main sewer trap