Water pressure will always be less for the hot water line than the cold water line because of the increased fluid friction caused by the longer path the water takes through a series of valves, fittings, the water heater itself, etc. as it travels to it's outlet. If the pressure on the hot water line is greatly reduced, it's usually caused by lime build-up in the hot water tank (dip tube) and the related fittings near the heat. Sometimes a washer in a tank shut off valve will wear, come lose and partially block the hot water line inlet or outlet line. If the system uses a tankless coil, it's usually lime build-up. This can be easily remedied using an acid wash. This is not difficult, but requires a little know-how.
How can anyone state hot water pressure will be less then cold?There is something called pressure temperature relationship THUS heated water WILL INCREASE PRESSURE even in domestic supply as the T&P on a water heater is set to relief PRESSURE @150 PSI which is well above the normal incoming presure of a street main
Check the water valve on top of the water heater. If it is off, you may have an easy problem to solve. You also may have mineral buildup in the hot water pipes. How old is the house?
Because hot water and cold water have different circuits.
The hot water side of your tub and shower diverter is plugging up. Replace the cartridge to fix the problem.
Pressure is the same whether hot or cold.
This is probably a pressure imbalance problem or you have air in the lines. see the related video link provided.
There are several possibilities. The 2 most common would be the water heater needs replacing, or you need a repipe.
Possibly a frozen line huh?
Lots of stuf can cause it including sediment or a blocked supply line
Hot or cold?
water pressure
Install on cold water line.
Ones hot and ones cold.
More than likely it is restiction in your water heater.
My guess is that the hot water heater is installed downstream from a pressure reducer to limit the maximum water pressure that the water heater is exposed to.
Sounds like your main line coming in is small if it's 1/2 inch stepping it up to 3/4 coming in then down to 1/2 inch would increase your pressure