I recently moved, and when I got situated, I simply added water to the tank, plugged it in, and turned it on. While warming up, the ususal hissing noise before the pressure and temperature starts building, kept hissing for about 4-5 times the usual length of time, the pressure was at zero, but the temperature almost pegged the needle. I shut it off, as the machine had lost it's prime and would not pump any water. Later after it cooled down, I primed the pump, which is fine now, but the machine no longer heats the water or builds pressure. what do you think?

wait for the new washer/ valve to settle in
or turn down the inlet water tap a bit

what does this really mean
tank topping up with water and re filling occasionally

in the wrong way or too tight or the wrong part ?

Bad relief valve or too much pressure in the tank. Does water heater system have a pressure blotter tank that allows for expansion(an expansion tank)

Sounds like one hose is turned off or plugged. The buzzing is ususally the inlet valve without water going to it.The machine will wait forever. Verify that both hoses have water on and actually flowing.

The typical situation is the hoses get hooked up backwards, but both are turned on, no one notices.....Dad gets big hot water bill, and turns off hot water (routed to cold inlet valve) Washer uses hot or warm until rinse cycles (which need cold water, which dad turned off).... Machine gets halted waiting for water....

either the hose in the tank is plugged or the valve is not turned on all the way

If you have lost a substantial amount of coolant, filling the reservoir doesn't fill the system.
If you don't have a radiator cap (many cars don't any more) it is necessary to pass through several cycles of warm-up and cool-off before all of the air in the system is displaced by coolant.
A pain in the **** when no fill is available on the radiator since it was simple to correct with that arrangement; you simply removed the cap, started the engine, watched the water/coolant level while the engine warmed up and once the coolant showed movement (circulation) you simply added coolant/mix a few times until it was full again. The movement of the visible water/coolant meant that the thermostat had opened and coolant was starting to circulate throughout the engine and radiator.

Sounds like you got a leak all right Check compressor clutch as well Motor revs should fluctuate when compressor cuts in and out Could be the seals in the compressor as well You need to find where the hissing noise is coming from

1. Start with a stone cold engine
   
   
2. Open the radiator cap
   
   
3. Open the radiator drain plug and let out as much coolant as will drain';
   
   
4. Replace drain plug and refill the sytem with distilled water
   
   
5. Run the engine for for few minutes until it is warm (not hot);
   
   
6. Repeat steps #3, #4 and #5 until you've effectively replace all of the coolant with distilled water. You'll know your finished draining the system when only clear water drains out.
   
   
7. Drain the system one last time (now only residual distilled water should be in your cooling system);
   
   
8. **** out all the coolant in the overflow tank (I use a Turkey baster or a huge syringe with a short length of rubber tubing.)
   
   
9. Replace the radiator drain plug.
   
   
10. Add undiluted anti-freeze to the system;
    
    
11. Run the engine to mix the distilled water already in the cooling system with the newly added antifreeze.
    
    
12. Check the antifreeze/water concentration with a tester.
    
    
13. Over the next few days, adjust to the desired antifreeze/water mixture over the next several days. You'll likely have to **** out a little coolant mixture from the fill cap to create room for either the distilled water or the anit-freeze you'll be adding to adjust to the desired concentration. Sometimes I adjust by adding either water or antifreeze to the coolant- overflow tank which utimately mixes with the engine coolant;
    
    
14. Don't forget to add collant and/or water to the coolant overflow tank.

its your flaot in your little carb

Clean the unti - and do not add salt. I live in a major hard water city...and was amazed at how much dirt the tank collected. I tried adding salt to to stop the spitting, which did make a lot more steam, but did NOT stop teh water spit. I also noticed, with salt added, water in tank would only last 4-6 hours, not the 18-24 hours it should. I just figured it out, and now mine works great again, and does not spit. I cleaned the water tank throughly, several rinses, then wiped out entire inside. If you want it to work like new, you have to keep your tank as clean as new. I am going to start filtering my water that I put in with a double pantyhose I made simply so there no more dirt ~ a clean tank will fix the problem, it did mine :)

I got my machine for Christmas and I have had the same problem almost everyday. Usually wiping down the water supply area worked but not today.. I have spent the past hour and a half trying everything I read online. Finally after reading the gray thing that floats in the water tank was a magnet I decided to maybe try to "reactivate" the magnent/sensor?.? I dumped all the water out and rubbed the magnet up and down the outside of the water tank making the gray block move up and down.. I even rubbed the magnent on the black surface where the water tank goes and the gray thing-e touches when attached.. To my surprise It worked!! It may have been pure coincidence..I dont know..but I figured I'd share anyway..It's worth a try!