30 sec of hot water - Bosch AquaStar Indoor Natural Gas Tankless Water Heater with Vent Hood #125

turn off gas
turn off cold water to heater
connect hose to spickot
place hose end outside
turn on spickot
open hot water faucets in house
wait.
when water stops, turn on cold water for 30-60 sec or so to try to stir up any sentiment in tank
turn off cold water and let drain.
close spickot
turn on cold water
let fill till water start coming out hot water faucets then turn off hot water faucets.
turn on gas and relight pilot.
finish bleeding air from hot water faucets.
set water heater thermostat

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

Here is website for brochure and support center. http://www.atwoodmobile.com/water-heaters/atwood-water-heaters-brochure.asp

If it's electric it sounds like the elements.

Remove access panels on water heater's side the top thermostat has a red reset button on it.
Press reset button and it will take about 30 mins or more to get hot water. If you have a meter or test light check wires to elements for power.

This would be the first thing to check on the water heater.

I am afraid that you have burned the heating element out or an inline fuse is burned out

try to remove pipe you could have a clog water,ice,nest. also you may have a bad pressure swith hose find the hose and **** to see if it will fire
also if you take your pipe of you make turn on to see if you get fire you can not run for more then 30 sec with this off co. will fill the house.

The thermocouple is a screw in type or 2 wire. You can check the dc MILI volt output with a multimeter. It should probably make 500-750miliVDC when heated. Be sure no plastic from the thermocouple wrapper was on the threads, will not work like that. To light did you push and hold the valve for 30 sec after lighting the pilot then turn to run after the pilot was burning? There is a slight chance the gas valve is bad but not likely. Check the wireing on the thermocouple to the gas valve.

faulty fan

lucky for you I jst did one of these the other day same problem,, check the wires on the ignitor, some of them are thinly coated and causes them to short out, wrap electrci tape around them individuly turn off the unit , wait 30 sec, turn it back on at it;s lowest tem hold both temp buttons at the same time till lights come on the after it lights set the temp