I have a single knob, pull out franke facuetts with very, very low water flow. good pressure to the faucett. about 5 yrs old. has always been low pressure but now is really slow.

It sounds like you have a scale problem which can seriously affect your water flow. If the water heater is older than 10 yrs, then this may be your problem.
If so, try draining the htr. First off, turn your heater off. If electric, turn off 30 amp two-pole breaker in your elec panel. Your elements may also be scaled up, thereby reducing their effectiveness. If you have little hot water, your bottom element and t-stat may be bad. If the electric heater is older than 10 yrs old, then you may want to consider replacing it as the average lifespan of a heater is about ten years. If gas, just turn the control knob all the way down. Attach a garden hose to your heater drain valve. Run the hose outside and open the drain valve with the water supply to the htr still on. This uses water pressure to blow out the scale that is likely clogging the drain valve. Blow it out for ten seconds, and then shut the valve feeding water to the htr.
Shutting the valve creates a vacuum so the draining will slow way down. To speed this up, turn on hot water all around the house. Do not do this with single handle faucets because cold water will cross over. Only the hot on two handle faucets should be opened.
If you don't have any two handle faucets, you can either turn off the water main and open the single handle faucets, or flip the lever up on the relief valve located on top or on the side near the top. Pull it so that it sticks straight out. This locks it in the open position and allows air to enter, and water to exit. Drain until no more water comes out.
Please keep in mind that if your heater is old, the scale may be the only thing keeping it from leaking, and this may expose that leak.
If none of this works, your inlet and/or outlet on the heater may be scaled up. This requires the removal of piping and scraping out the scale. Once again, if the htr is old, (over 10) you may want to consider just replacing it.
GOOD LUCK!

If the unit is indoors, the pressures are not that bad. I would look for possible issues with air flow. Maybe heavy frost forming on evap. If not, then go to basics. Remove charge, replace filter/dryer, pull good vacuum, weigh in the charge. This usually eliminates most problems.

Diagram is here http://www.ereplacementparts.com/moen-7175csl-kitchen-sink-faucet-parts-c-143601_143605_143680.html

There are two possible problems:

1) The crud you don't want in aerator can get stuck in elbows and shut-off valves.
Open following link for steps
http://waterheatertimer.org/Low-hot-water-pressure.html

2) Crossover. If single-handled faucet has bad cartridge, or check valve is bad, these things can cause hot water not to flow.
Generally however if the pressure is still good, the issue is most likely #1 above.
http://waterheatertimer.org/pdf/Crossover-on-single-handled-faucet.pdf

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Pull the screen off the faucett, from the new install you probably clogged the screen. If you get good flow without the screen, clean your screen out and re-install. You will need to twist off the piece and the end of the faucett to get at screen. Pay attention to how it comes out so you can put it back in the same way.

An F20 code is telling you that the anticpated fill time limit has been exceeded.

This can be caused by
1. Dirty water inlet screens on the water valve. Also possibly the hoses at the wall connection if the unit was installed with additional hose screens.
2. Kinked water supply hoses
3. LOW WATER pressure
4. A weak or open coil of the inlet water valve solenoid.
5. A kinked or restriction of the hose that goes from the water valve to the tub inlet.
6. (VERY RARE) A defective machine control board.
7. Bad faucett washers on the wall connection hose bibb where the rubber faucett washer has deterorated and is blocking or restricting water flow inside the shut off valve on the wall.
8. Debris blocking the diaphram of the water passages inside the inlet water valve (Can not be verified by disassembly due to the construction of the water valve.) You must check flow rate into the tub after verifying all the possibilites above except #6.

These are all real possibilites and each one of them must be checked out. This is not a difficult task and a good many washing machine users should be able to isolate the problem.

If you need machine specific information we will need your make and model number to assist you in the future.

Thanks for choosing FixYa.

Kelly

crud in the supply lines or valves.

Go to home Depot or loew and buy the seat replacement kit for your model of faucett. Your going to have to break out the tools (Philipps Screwdriver and a larger adjustable wrench) The remove the shower knob cover with a knife to access the mounting screw. Remove the screw and then the knob. (STOP!) Go turn off the water for the residence now! Then come back and remove the nut holding the faucett in place. The whole assy will with a little effort will come straigth out at you. Moen isnotorious for having to remove a plate from the bottom of the valve. NOTE the position of that plate and then remove it. Remove all of the seat seals one at a time and replace them with the new ones you purchased. Reinstall the NEW lower plate in the same position you removed the old one. Reinsert the assy back into the valve body. Tighten the retaining nut. Reinstall knob and secure with screw. Replace knob cover. Turn on the water NOW. Enjoy the non-leaking faucett.

Replace cartridge and insure that the C clip is not missing.

This is a common problem. They are desighned to come on when a certain volume of water goes through it and with todays low flow water conserving devises they don't always come on with one faucette.

You can have a loop installed that allows a higher volume of water to flow when a valve is turned on. It simply flows back into the supply side of the unit.