In the past 2 weeks I had low Hot water pressure. I fixed that problem by replacing the inlet and outlet nipple fittings. (Both were clogged/corroded).
Now, I have good hot water pressure but only in the master bath and laundry room. The MB is the fartherest point away from the hot water heater and the laundry is the closest point. I have good cold water in the master bath and laundry too. However, I have very low pressure in all other areas of the house. Could I have an air lock somewhere?

Here's a run down:
Master Bath (2nd floor) has good pressure
Guest bath (2nd floor) has very low pressure
Half Bath and kitchen (first floor) have low pressure.
Laundry (first floor) good pressure

Hi Rodger,

"In the past 2 weeks I had low Hot water pressure. I fixed that problem by replacing the inlet and outlet nipple fittings. (Both were clogged/corroded)."
The inlet nipple and outlet nipple to what? Remove the aerator from the kitchen sinks faucer spout and tell me if the screen's clear or if it has crud on it. I'll wait on your reply. Tom

Tom,
The inlet/outlet nipples are on the hot water heater. Also, I replaced the dielectric union as they were corroded too.
The hot water is normal now.

The problem is with no prssure or very, very low pressure in certain areas of the house. I did clean all aerators as well. My discovery is that the 3/4" pipe feeds my upstairs master bath (sink and tub) and 3/4" goes to by guest tub. Also, 3/4" supplies the laundry. Those areas are fine. It appears that the areas that are split off with 1/2" pipe are the ones that have no pressure or just a trickle. Those areas are the kitchen, half bath (both on first floor) and the sink in the guest bath (2nd floor). Hmmm? Boyles Law?

Roger

Open up the kitchen faucet and check the inlet ports of the cartridge for crud or trash build up. Now place a pan over the open valve body and turn on the supplies to flush them out. How often do you flush your heater? It should be done once a month and more if you have a high mineral content in your water.
Regards, Tom