Question about Amtrol ST-12-C THERM-X-TROL ASME Expansion Tank, 5 Gallon
Since you mentioned 'both temperatures' it seems your unit is like most all of them, a lower and upper coil.
If your hot water supply runs out quickly, this normally means that the lower coil has failed. Since heat rises, the upper coil will never supply a tankful of hot water, just hot to start, and then as the flow continues, it doesn't have time to do more than warm the water flowing into the tank.
Every home should now own a simple digital multimeter; they cost less than $20 US everywhere and one can find them in auto parts stores, electronic supply companies and tool companies.
If you have a Harbor Freight tool store in your area, you can get them for under $10 US any time and sometimes even less:
You need to be absolutely certain that the voltage to the water heater is shut down. Before you measure anything else, set the meter to its highest AC setting and check across the coils and then from either contact to the metal housing. If it is dead everywhere, then set the meter to the lowest Ohms scale (normally 200). The resistance of the coil should be nearly the same reading as when you simply short the meter's probe tips together. If it measures 'OL' then the coil is open and must be replaced.
Posted on Feb 26, 2009
SOURCE: Amtrol Boiler Mate WH-7P (oil).
If you check for power at the tank, (the black and white wires) you should read voltage, either 24 vac, or 120 vac, depending on how it is wired. If there is no power there, then you will have to chase power back to where you do have it. There is no fuse or reset button on this model.
Posted on Jan 19, 2010
Hello 23+yrs is execptional service! Yes it is leaking into the boiler.Time to shop for a new indirect hot water heater.Forget a coil.Thanks
Posted on Apr 01, 2010
Testimonial: "Thanks for advice, my hard, low ph well water finally caused a pinhole in the coil. Thanks for supporting my theory."
SOURCE: HELP... my flush line from
I can understand your wanting to not waste money but in thirty years in business I always said If a piece of equipment had been flooded then be safe and replace it. I know it's easy for me to spend other peoples money but that is what I would do. Best of luck and thank you.
Posted on Mar 07, 2011
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