When I flush my toilet downstairs my upstairs toilet emptys about 1/2 of the water in the upstairs toilet bowl . Whenever I use water anywhere in my house it girgles when it drains. As far as I can tell there is no type of venting system for any of the plumbing . What would be the most ecomical way to fix this problem .
To not have any venting, this would have to be a very old house which was originally built in some unincorporated area which had very loose, if any, building codes. If what you describe is true, then there is no “cheap” repair.
I have to agree with hj. If there are no vents, then there’s no quick fix with your problem. Are you sure that there are no vents? Are there any plumbing vents pipes visible on you roof? If so perhaps a vent could simply be clogged and may have to be snaked out to correct the problem. Good luck