Have made the manual adjustments to increase the water flow but no increase in flow out of the bubbler. Is there a filter or part that needs to be replaced to allow better water flow?

The lit red button may be an indicator that the water temperature inside the water heater flow channel has become too hot. If the outflow facet is adjusted to allow more water outflow (opened more) the water temperature should drop some and therefore with increased water flow, the temperature inside the water heater will also decrease. Or, if there is a manually adjustable outflow valve on the water heater, adjusting it to a more open position would also decrease the internal temperature.

are you sure you didnt plug the blower in the heater outlet on the control box ???
if not i suspect you have a common problem with these units (water intrusion) inside the control box this produces all sort of (gremlins) to happen

Check stream height from bubbler. Stream height is factory set at 35 PSI . If supply pressure varies greatly from this, remove the (bottom cover plate) and adjust the screw on the regulator Clockwise adjustment will raise stream height and counter-clockwise will lower stream height. For best adjustment stream height should hit basin approximately 6-1/2" (165mm) from the bubbler.

You can not increase the water flow through a heater by adjusting the heater. You either need to get a larger pump motor, fix a pump issue, or....
If the heater was installed correctly with a bypass, closing the bypass will force more water through the heater. If a bypass was not installed, a larger motor is needed to increase flow (unless you used to get enough flow and now you dont. I this case, fix the pump or backwash the filter)

Could be you need to give the coils on the bottom a good cleaning.
Keeping a good air flow on them coils increases ice production. Check your water filter. It may need to be replaced. YOUR SERVICE MANUAL


If you need further help, reach me via phone at https://www.6ya.com/expert/dan_73bbd84fe1d95b61

Could be a clogged filter..
Open pannel to find it and replace it..

Have a great day !

if you mean the amount of water that comes out of the bubbler head....you can adjust that by accessing the push button cartridge and turning it to adjust how far it is pushed.

http://www.aprilaire.com/themes/aa/en/manuals/600a.pdf look at page thirteen in this manual there is allready a inline filter on the unit. hope this helps

With a flat head screw head driver adjust the pump pressure. The screw is on the left side of the image below.