How many gallons of water per minute can I push thru a 1/4 inch valve with 150 psi

see if you can find out from here. https://www.google.co.uk/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=How+many+gallons+of+water+will+flow+thru+a+1/4+inch+valve+per+minute+with+150+psi+pushing+it

Just a little over 53.3 gallons

Typical faucet can be 2 gallons per minute
http://waterheatertimer.org/Low-hot-water-pressure.html#slow
http://waterheatertimer.org/Crossover.html

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) Copy following link to identify gas control valve:
http://waterheatertimer.org/How-to-troubleshoot-gas-water-heater.html#intellivent

2) Add a comment and describe gas control valve, and include if this is on boiler or water heater

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

body { background: #FFFFFF; margin: 0px; padding: 4px; font-family: arial, verdana, sans-serif; font-size: 10pt; } p { margin:0px; padding:0px; } .spwrap { background: transparent url(/wysiwyg_rte/misspell.gif) repeat-x scroll center bottom; } You are talking about length of time to get hot water from water heater.What diameter pipe are you talking about? What type of faucet do you have?
1/2" pipe has inside diameter of .54" and holds 1.2 gallons per 100 feet
10 meters is 32 feet and holds .4 gallons
Average faucet puts out 2 gallons per minute, so 30 seconds you should get 1 gallon of water.
Put a bucket under faucet and check amount of water flow.

Assuming you draw just hot water from the faucet, then 30 seconds is slow for receiving hot water.
If you have single-handle faucet and raise handle straight up in middle, then you are drawing half hot and half cold, so it would take 30 seconds for hot to arrive.

If hot water is slow, the problem might be crossover.
http://waterheatertimer.org/Crossover.html
or low water pressure due to clog in water line
http://waterheatertimer.org/Low-hot-water-pressure.html
Other problems could include clogged water filter, clogged water softener, defective pressure valve, and low water pressure.

Sources:
http://waterheatertimer.org/Troubleshoot-Bosch-Tankless-water-heater.html
http://waterheatertimer.org/Water-heater-recirculation-system.html

Electric water heater typically makes 21 gallons hot water per hour.
Gas heater makes 41 gallons per hour.
If you use a timer on electric heater, it will make enough hot water for shower in about 15 minutes summertimer and 30 minutes wintertime. So incoming water temperature is a factor.

If your water heater is not full of water before turning on electricity, then elements will burn out.
Also the ECO might be tripped out: open top cover and push in red reset button.
How to troubleshoot electric water heater:
http://waterheatertimer.org/How-to-troubleshoot-electric-water-heater.html

The easiest way I know of is to remove cap from air valve on top of tank and check pressure with tire gauge.If you get water out of valve then air bladder is bad and tank will need to be replaced. If you don't get water but no pressure then reinflate to 3-5 PSI. Hope this helps. Thanks

I believe you have a high water pressure going to the
tank. Minimize the water volume going to your tank. This is done by fully closing the inlet valve under the tank. Then open about 1/4 to 1/3 of the inlet valve. To do this, count the number of turns to get it full close from full open position. For 1/4, divide the number of turns by 4 and divide it by 3, for 1/3 open. Hope this will solve your problem.

Hello. let me help you. The water pressure is what it is in the house. In other words, the tankless water heater doesn't increase the pressure of the water, it only heats the water. There is no official minimum pressure but the minimum pressure you would be happy with in any home would be 20 pounds per square inch, PSI.

if the leak is behind the handle take the handle off and tightn the packing nut, do not over tighten, as far as luke warm water is this with just one facucet on, they way these tankless water heaters work they are by gpm, gallons per min, if you have more gallons of water going thru the unit then it is designed for then it won't get hot, if your water pressure is to high going thru it will push it to fast thru the unit and won't get hot, your house pressure should be no higher then 75lbs no lower then 65lbs