We just bought a 2200 sqft single level home in Florida with PVC pipes laid under the floor. We knew when we bought the house that the lower element was burnt out on the hot water heater and that it was most likely filled with sediment due to water pressure issues when more than 1 faucet was turned on at the same time. We replaced the water heater with a 65 gallon electric heater and that solved our pressure issues but now we have a problem getting hot water to the faucets, and it doesn't matter if the faucet is 30 feet from the tank or the furthest from the hot water tank, the issue is the same- you turn on the hot water tap and wait anywhere from 55 seconds to 2 minutes for the water to get warm. If you turn off the hot water and turn it back on again it starts cold and you have to wait another 55 seconds-2 minutes again for hot water. When my husband showers and gets out and I get in the water has only been off for less than 2 minutes, tops. I get a blast of warm water that lasts for a second or two and then it goes cold and eventually turns hot.
This is totally maddening. The plumber that installed the hot water heater suggested a circ pump but I'm on city water and am getting 60 psi for pressure and the neighbors do not have a circ pump and don't have these issues and their house is larger than ours. Any help would be greatly appreciated!

Are you on concrete slab or raised foundation ?

It is design problem. Yes, hot water circulation pump is your solution. Also, install insulation on hot water pipes.

Hope that helps. Milo

Can you test the temp of the water when you run just HOT only, should be about 120. Seems odd to me that a 30' run also takes the same time to heat up as the longest run. I'd love to see a psi test on the cold only and then hot only but that is not all that easy to set up, I think you have a hot volume issue. If you open the drain spigot on the heater and install a temporary pressure gauge you should see the same psi as you will find on your outside garden spigot.