Question about Amtrol ST-12-C THERM-X-TROL ASME Expansion Tank, 5 Gallon

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Amtrol wh7p My basement flooded and I am trying to reset my amtrol wh7p oil hot water heater. please help . the furnace works but the hot water heater will not . i cant figure out how to reset it? When i turn furnace off and on the hot water heater comes on for a few seconds then goes off. do i just need to reset it? could therebe another issue? i am not even certain the water reached it as it was very low and i have seen it flood more and not impact hot water heater.

Posted by bdjc2001 on


5 Related Answers


Steve Allison

  • 5569 Answers

SOURCE: not enough hot water. I have an Amtrol Extrol coil water heater

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:
Digital meter   
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


Keith Fournier

  • 308 Answers

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


SOURCE: I have a 23 yr. old Amtrol WH7P that has sent

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."


  • 1 Answer

SOURCE: ER3 no hot water

Er3 means that the water is being heated for more than 1 hour without reaching the set temperature.
Need new aquastat.

Posted on Dec 28, 2010

Jack Spooner

  • 1015 Answers

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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