Did the water in the bowl change colors from the food coloring test?

the bowl primer tube could be siphoning water, or the actual filler seat could be bad.

Even the gaskets and seals of the flapper seat to the tank could be bad.

Brickeyee, Yes, the bowl water did become colored.Bowl primer and filler seat are not words I know about so I guess you are saying I do need a plumber.

The 'bowl primer' is the small tube from the tank fill valve that is routed to the tank overflow to make sure the bowl has enough water to fill the trap.

If the end of the tube is below the water level in the tank it can siphon water from the tank.

The 'filler seat' is the surface the flapper closes on to seal.

If it is rough or damaged the flapper cannot seal.

If the fill valve seat was leaking the flow would be constant and the water level in the tank would be above the top of the standpipe regardless of where the float is set.

If the flush valve tank gasket was leaking the leak would be on the outside of the bowl and making the floor wet.

PPL have repeatedly said it could be the trap primer line syphoning water, but that is also nonesense. First off, the trap primer line is attached to the fill valve, which is required to be a minimum of 1" above the top of the standpipe and per code ALL FILL VALVES must be designed to meet a very strict anti-syphoning specification. in a nutshell, if the fill valve is installed correctly syphoning is physically impossible.

If the water from the tank is leaking into the bowl there are three distinct problems that should be checked.

1. Lift the flapper and examine the flapper seat on the flush valve (the flat surface that the flapper sits on, surrounding the hole were the water goes down to the bowl), Gently run your finger nail along the top of that surface and feel for pits or mineral scale buildup on that surface. If it feels rough or gritty you can sometimes correct the problem by buffing that surface with fine emery paper to remove the mineral scale.

2. Check the flapper and make sure you have the correct one to fit your water closet. Years ago they were all one standard size but with the advent of water saver toilets they now make about a half dozen different flappers.

3. Make sure the flapper is mounted correctly. Most flappers have two tabs with holes that fit over little arms projecting out from the standpipe. Make sure the flapper tabs are completely on the arms and the flapper is free to move up and down. If either one of those tabs are only partially on the arm it will not rotate correctly, generally leaving one side of the flapper slightly elevated above the seat or out of alignment so the flapper cannot seal correctly.

4. Check the flapper chain. If the chain is installed correctly, when the flush handle is in the at rest position the chain should rise up to the flush handle with nor more than two chain links of slack. If the chain is too long the excess chain gets pulled into the flush valve during a flush and it then prevents the flapper from closing down on the seat correctly.

5. If the afore mentioned methods do not resolve the problem, then the problem is most likely a crack in the side wall of the standpipe or a crack where the standpipe attaches to the flush valve body in the bottom of the tank. The solution here is to replace the flush valve, but not to worry, replacement flush valves are cheap and easy to install.

Lazypup, thanks so much, I will ck. the 5 situations and hopefully fix the problem. If none help I will have to call the professional as a last resort. Thanks again.