Hi
Drained out the hot water heater yesterday and now I get low water pressure out of 3 of the faucets just 3 out of the whole house. I did pull the pressure release value while it drained which I now know I should not have done

In draining the tank you may have stirred up some trash that worked it's way into the three faucets that you are having low pressure on. I would take them apart and see if that is the problem.

Hi
Drained out the hot water heater yesterday and now I get low water pressure out of 3 of the faucets just 3 out of the whole house. I did pull the pressure release value while it drained which I now know I should not have done
Letmetellu is right on with his answer. Shut the water off, open up the valves and check for trash in the inlet ports of the cartridge. Before you reassemble turn the water back on for a moment to flush out the supplies and valve body. Opening up the P&T relief valve while draining is important to relieve air lock when draining a water heater, however you don't need to completely drain the heater. You flush it, not drain it. Let me show you how. For long life and fewer troubles you should keep your heater clear of mineral build-up by flushing on a regular schedule. Attach a hose to the boiler drain at the bottom of the tank. With the pressure on, open the boiler drain and let it run until the water runs clear. You will see a spurt of red,(rust) followed by white or yellow grains,(lime or calcium carbonate). This shouldn't take more then a few minutes. Do this monthly to keep it clear. Now flush out your hot water lines on ALL fixtures that are affected . Now pull each aerator and clean the screens. Be sure you put them back togather the same way you took them out. Don't forget to flush it out every month. Your heater will thank you for it. Hope this helps, Tom