All lamps neons:
Blue lamp tells the water heater is energized. Parallel to mains.
Green lamp tells temperature is reached and element is fine. Parallel to thermostat.
Red lamp tells that heating element is heating now. Parallel to heater element.
A high resistance open in a heater will still light the neon indicator! Water itself can conduct adequate current to light the neon.
Elements can be tricky. They often look like 'swiss cheeze' with a deteriorated sheath. The element is actually open, but it still has leakage resistance that's way too high to do any heating. This would give a false 'element OK' indication.
Ahem.... Current again I say!
Len
“To invent, you need a good imagination and a big pile of junk.” (T. Edison)
"I must be on the way to success since I already have the junk". (Me)
Externet >> i'll look at them more, find specs on them... i'll also look in my junk box of PS's
i got an idea also for bench testing before i try to test them in my heater..
i have a Weller soldiering gun , 180W i can use a old coat hanger to pass current, i can use my clamp on meter to see how many amps that makes, i am sure it is very high. if it generates the current i want, then i can test it in my heater..
i'll keep ya posted..
BTW does anyone know the current draw on the gun tips ? mine is a old 180W gun.
burns up tips about every 1-2 months..
Current on a 180W soldering pistol... Would be interesting to know the voltage without the tip... perhaps a couple of volts AC ? That will drop to less than a Volt AC with the tip in place ?
Lets say 1 Volt AC with the tip in place... 180W divided by 1 Volt ----> ~180 Amperes...
By the way, any 12 gauge copper wire works perfect instead of a branded replacement tip.
Miguel
The tip is like a dead short. I once put a clamp on meter on a tip and I think it was over 100A. The gun was a Weller dual heat and I don't recall the rated wattage.
If the gun was 100 watts, and tip was .5 ohm, that's 200A neglecting any quibble factor!
I'll bet with some creative machining you could make a battery tab spot welder
Len
“To invent, you need a good imagination and a big pile of junk.” (T. Edison)
"I must be on the way to success since I already have the junk". (Me)
I stand corrected . I must have been thinking of limiting voltage "in the water" with 115V elements. But then you'd have trouble getting enough energy into the water. When I get on the wrong track, I can take it a long way! Got me to wondering; is there another hole in the tank below the element for the thermostat?
I must be the "others" we're told to learn from their mistakes .
Typically in domestic water heaters the thermostats are surface mounted to the tank. There are no penetrations.
Commercial heaters often have thermostat wells for more accurate control.
Side note:
In large buildings often there is a domestic hot water recirculating loop and all the appliances are tapped into it. That way gallons of water are saved while someone waits for the hot water. A thermostat monitors the return loop temperature and a valve controls the water coming from the water heater to keep the loop at a set temperature. The pipes are well insulated so the heat loss is tolerable.
Usually that's not a practical system for a home unless cost is no concern!
Len
“To invent, you need a good imagination and a big pile of junk.” (T. Edison)
"I must be on the way to success since I already have the junk". (Me)