Heater problem....HELP PLEASE

[Jim Andrews]

We have run in to a problem that we have yet to figure out. While washing with cold water everything is great, when we kick in the heat runs it great for 20-30 minutes then starts spewing steamy, brown nasty water. We have cleaned the coil and changed flow switches. A black plastic piece in the flow switch actually is melting and pieces are clogging up the unloader, tips, etc. Our dealer says the coil is restricting the flow which in turn makes the water hotter and creating back pressure when not washing...his solution is a new coil = big bucks. Another repair shop says no way it is the coil, it has to be a switch or something. With the trigger gun constantly pulled it runs great, problems start when you let off we get the above described problems. Any ideas or opinions would be greatly appreciated.

 

[Hotwaterwizard]

Low flow can be caused by many things.
Air getting sucked into the water is the most common cause. Check all of the hose clamps first. Also check the water inlet screen and make sure the soap valve is closed. Make sure the soap check valve is in water if not in use. Check the Vacuum switch if it uses one and check the pop-off valve for leaks. Finally check the valves in the pump and make sure the packings are not bad inside of the pump. Cracked plungers can also cause the same problem. After checking all of these things if the problem still exists call me.