Gerber Flushmate back flush problem

I have a Gerber Flushmate series 503 model M-101526-F3, about 1-2 years old toilet. It's water level is very low, barely filling the opening. When flushes, water shoots back up the hole and settles back down. Been working great till now, how do I diagnose this?

Sounds like you have a venting/drain-line issue. Does this happen all the time, occasionally, frequently, etc.? Was the water level in the bowl adequate until recently or has it always been like that? Will pouring a bucket of water into the bowl "flush" it and refill it?

Something is amiss...

I contacted Sloan and was advised that the problem was probably due to something clogging the small jet hole in front which redirected the water inflow upwards instead of straight across and into the trap. Was advised to use a small brush such as a baby bottle brush to clean this jet hole out.

I did this with a 6" long about 2" thick baby bottle brush and it didn't help. Called Sloan back but they were closed. Tried it again more vigorously a few hours later and it worked. Whatever was catching in there must be quite small as I couldn't tell if anything came out. The seeming back flushing was simply due to a misdirected water inlet jet stream caused by something blocking that little jet opening.

Glad the fix was simple as I understand these pressure assisted units can't really be fixed. Have to say this system is quite powerful and flushes everything.