Plumbing – Replaced the water heater and now I have very low water pressure both hot and cold

I assume when you drained the tank, you turned off the main cold water supply. I suspect that the cold water valve is not opened all the way now. Check to see if in fact it is open full. If it is, and the pressure is still low, you may have a jammed or damaged valve. This is very common on old valves that are not used very often. The seats and washers inside the valve can degrade over time and now are not allowing water to pass freely.

The pipes are not likely to be blocked. The problem will most probalby be in the tap. Most taps usually have a aerator before the exit and that could be blocked up from dirt.

To clean the tap there is a tool to remove the aerator but it is not necessary. You can use pliers or a the correct size key.

There is also a helpful video here

And this is what the part looks like when its a bit clogged.

With the clog that you mentioned it must be pretty bad- So when you remove the aerator you will most likely see allot of dirt follow it. Open the taps for a minute to get it out of the system.

This dirt usaully comes from the main water supply so installing a filter for your main supply for the house if a good option to stop this nuisance. There also options to improve the drinking qualities. Ask you local plumber depot for advice.

DIY TIPS

• To avoid damaging the aerator body it is a good idea to wrap it with some cloth and gently try to unscrew it. It could be a bit stuck but wiggle it back and forth and should let go easily.
• Many aerators go into several pieces. The can help in cleaning them. Try to remember the order.
• The aerator is not mandatory. It helps make the water come out silky and uniform which helps to prevent splashing. You can use the tap without it if it clogs up frequently.