Water pressure volume low. I would like to get inside to see what is happening but see no visable way to take apart .

http://waterheatertimer.org/Low-hot-water-pressure.html
Link above have general troubleshoot steps to determine possible causes of low pressure

Gene

Water Heater Timers Save Money

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

1) If possible, it is Best to solve pressure problem before installing new shower.
http://waterheatertimer.org/Low-hot-water-pressure.html

2) If the cold water has good pressure, then Electric shower could fix problem ... but shower would have to be connected to the cold water line and not the hot.

3) Seems the expense of adding a electric shower would be greater than having plumber fix low hot water pressure.
Assuming you have access to plumbing pipes, and this is not apartment building.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

1) Cheapest and most reliable solution: Install tank-type electric water heater from local box store for $250. Get store coupons, offer 10% off store price. Repairs are made same day with generic off-the-shelf parts.
http://waterheatertimer.org/pdf/How-to-install-electric-water-heater.pdf

2) Install grundfo water pressure boosting pump.
http://www.ronhazelton.com/projects/how_to_increase_water_pressure_in_your_home
http://waterheatertimer.org/How-to-solder-pipes.html

3) Remove areators and low flow shower heads, Maintain unit as shown in product manual: Delime tankless unit yearly, Clean water filter monthly.

4) Call city and report low pressure and report issue as fire hazard, move to different apartment. Call apartment complex and ask why they didn't read flow requirements for tankless before installing tankless.

5) Call Bosch 866-330-2729 and complain that nobody read the flow requirement or tested local water flow before installing tankless.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Detergent tanks will only draw at low pressure. Switching to low-pressure is done is several different ways with different makes/models. Some pressure nozzles are push/pull, some are twist and some just have a quick coupling and you have to keep up with a low pressure tip (usually colored black).

If it will not draw at low presser, it is either stopped up with debres, or the check ball inside the injector is stuck. The injector is the little device that is just before the outlet where the pressure hose hooks up. These always have a small metal ball, held in place with a tiny spring. This ball is there to prevent pressurized water from shooting back into the detergent tank. The ball and seat that it presses against can get stuck together with old detergent residues, calcified deposits from the water or even rust.

Use a small crescent wrench to take it apart -- or if you prefer, find the right size box end/open end (metric) wrench. Be very cautious as it comes apart because that little spring can leap out and they are hard to find.
I hope this is helpful to you. If it is, please take a sec to rate me. Thanks!
Don

You might have clog in water lines.
If shower is only place where low pressure exists, then clog is probably at shower valve.
Disassemble valve and see if clog will flush out.
From there, you have to keep moving back along cold water line looking for pipe filled with sediment or elbow that has obstruction.

If pressure problem is bad at every cold tap, but doesn't affect Hot water, then clog is inside Cold line somewhere after water heater connects to cold line.
Buy a pressure gauge that connects to water hose.
Buy adapter that also fits pipe thread.
For example Brady BTG 100.
Test outdoor spigot for baseline pressure.
Open cold tap inside house and see how much pressure drops.
Close cold line and open hot tap and see how much pressure drops.

Next, move pressure gauge along cold water line.
Take apart pipes and inspect for obstruction at elbow or pipes filled with sediment.
Look for any place galvanized pipe connects to copper pipe, since this will be likely place for obstruction because of bi-metal corrosion.

Add a comment for more free help.
Also take advantage of fixya phone service.
For a price, fixya expert speaks with you over phone while you work on pipes.

When water is heated it expands. To deal with this all boilers are fitted with a small expansion vessel which is like a reservoir which holds the excess water.

This expansion vessel is like a balloon in a metal pot. When the water goes in the metal pot the baloon squashes a bit to make room for the extra volume of water. When it cools the balloon pushes the water back into the heating system.

What has happened is your expansion vessel no longer works. When the water heats up there is nowhere for it to go so the pressure jumps up to 4 bar. The Worcester boiler lets high pressure water escape (most boiler allow this to go through the safety valve at say 3.5 bar).

When the water cools the pressure drops very low as the volume of water contracts.

The problem is your expansion vessel - normally a little red painted metal cylinder inside the boiler.

All the Sevylor tubes have a valve that comes apart in to two pieces, remove the top and you can fill remove the hole thing releases the air. You need a 12 volts high volume low pressure pump with connectors, 20 bucks in Overtons. Fill it till it is stiff, put it in the water let the air cool down inside then hand fill it with the connector and human breath to stiff it up again.

I worked at a tool rental while attending college and had the opportunity to work on a variety of pressure washers, however, they were of the commercial type. Commercial washers are slightly different in that they usually have seperated components for easier service. Attached to the pump by fittings or rubber hose were the pressure regulator (which has the bypass unloader inside), chemical injector, pressure gauge as well as the hot water release safety all external to pump. Your pump has all these components in one case. By far the most troublesome component is the pressure regulator/unloader which when failing will result in low pressure because it will bypass water back into the intake as you suspect is happening to yours. Here are a few things to check. I believe that your pump is 2500 2.4 gpm. Test gpm water capacity by running pump normally with hose and proper tip attached. Spray water into bucket for one minute and verify that you are pumping 2.4 gallons of water (or what ever gpm your machine is rated). Measure the amount of water that your machine delivered. If it delivered proper gpm and pressure is low then problem could be worn or improper tip. The pressure is created at the tip and pressure will drop as the tip wears. As the unloader/bypass wears, water will bypass at a lower pressure. (Try lowering the pressure regulator all the way ) If water measures less than rated delivery than the machine is bypassing water due to worn regulator/bypass, checkvalves pitted, oring in front of checkvalve worn or cut or missing, or body of pump where checkvalve/oring seat is pitted allowing water to leak past valve. The cap that is removed to access checkvalve must presses against checkvalve with enough force to prevent water from leaking thru oring and body of pump. Examine checkvalves and orings with maginfy lens and look for pitting. Valves surface and orings must be very smooth and tight fitting to work properly. Body of pump where checkvalve oring snuggs against must be very smooth. Any surface where oring seats must be smooth. As water bypasses it cuts metal and orings just like a leaking faucet so look for cuts in metal and rubber. This info and my experience is better suited for larger pumps and higher pressure but maybe it will help. Good luck with your repair.

Sounds like pump is not making pressure. Thats why you get flow, but no pressure.
If it sat for awhile, check shaft connection to pump. Sometimes the impeller or shaft will shear partially due to corrosion when stored. Seals on pump valves could be gone too. Get an exploded diagram, usually from owners manual, easily found for this model. Parts list should have "pump repair kit" with everything needed to bring it back to life.
You and a friend put it on the bench to work on it and save your back. The pumps are pretty easy to take apart and put back in working order.

all dishwashers i am aware off have their own heater and are better connected to cold not hot water