How to remove calcium buildup from pressure washer pump

There is a pressure release valve in the pump. That pressure release valve is frozen shut (probably due to calcium or lime buildup). Other than disassembling the pump and clearing the calcium mechanically the only thing that I can think of is pouring CLR (Calcium, Lime, and Rust remover) into the port where the water hose connects and hope that the CLR will dissolve the calcium or lime. Pour as much CLR in as you can, connect the hose and pull the trigger and immediately release the trigger. You may have to pour CLR into the hose port several times.

Some models have a tiny orifice in the adjustable spray head.(if equipped) Which can become clogged by debris or calcium buildup. Water should flow through even when unit is off and sprayer handle(on/off) is operated if there is no water then you definitely have a clog.

you need to clean the jet and fuel tube in carburetor you have to remove the fuel bowl to do this.

You have a buildup of calcium or other such minerals in the piping, or, your well pump is starting to go, check to see if pumps is operating the way is should.

check for oil in your pump. The water pump may be bad.

Could have a pinched hose or a calcium buildup. If you can't find a kink in the hose then run some vinegar through the system to remove calcium deposits.

Lime/calcium build up in the pump.
Pour a large amount of liquid TSP into the fresh water inlet and let it sit for two or three days, the longer the better.
This is how I fixed my no pressure problem.
Works great now

Chances are that your new pump is generating good pressure. Because of this, the engine is trying to turn over against the pressurized system. Try pulling the handle on your wand when pull starting the engine to see if this eliminates your problem.

It is a diaphram carb. Doe's the primer **** straight gas or does it have air bubbles in it? If it has bubbles in it then it is a leak in the fuel line.
If not then Unhook the intake fuel line and pump the bulb until all of the gas is out of it. Then pour the gas out of the tank and rinse it out with new gas. Pour in new gas and it should be ok.

Leaving the engine running for more than two minutes without releasing pressure trigger causes aluminum pump to overheat and causing damage to the purmp, resulting in sudden low pressure. (see page 9 in manual)