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Your cart is empty.Reliance 300 series, electronic gas thermostat control valve, thermostat powered by 750 millivolt generator, noticeable L.E.D. indicator light blinks 1 time at 3 second intervals during normal operation, increased temperature control and accuracy, integral spark igniter, only for Reliance standard natural gas water heaters with electronic thermostat control.
Divo Maddie
August 4, 2025
This control unit is exactly what was needed to get the hot water flowing again. Status light is white and brighter than the original. Followed Honeywell directions that said no pipe tape sealant on supply side. Compression fittings don’t need tape either. Leak checked and no problems. A small length of pipe screwed into the supply side makes for a convenient handle to remove the old unit and screw in the new one without damaging it. Quick and easy. Good deal. The failed unit was only 4 years old but I suspect the wild ambient temperature swings where it is installed caused the unit to fail. This time I will insulate it to make it last longer.
jasmine
June 27, 2025
But had to return
Kindle Customer
June 9, 2025
This replacement valve was exactly as expected. It arrived on time and as described. If you have some knowledge of water heaters and plumbing, it is fairly simple to install. There are multiple videos explaining installation. I would recommend replacing any plastic drain valves with a ball valve on the tank and replacing the pressure relief valve also while you have it drained. Both are pretty simple to do and will save you some potential trouble in the future. I would recommend purchase from this seller and the product is perfect. Cannot attest to the reliability of the valve as it has only been installed for a week or so. But, it is functioning perfectly now and at $129 and the time it took to put it in, it sure beats $600 for a new tank and the time it takes to put one of those in!
John Y.
March 14, 2025
Saved a lot of money by replacing the control valve instead of the entire water heater. This price was good for an OEM replacement part.
Ashley M
December 8, 2024
It was a direct cross for our failed unit WV8840B1109 to this new WT8840B1000.New unit comes with a new compression nut and compression ferrule for the pilot light tube. I would suggest you use it. Remember the burner and pilot nut are left hand threadsTools needed: wrenches 7/8", 3/4", 7/16" and I used one adjustable wrench small tubing cutter and tread sealer.Total time took a little over an 1.5 hour mostly due to the location of the water heater. It lit the pilot light almost immediately and the burner kicked in. No gas or water leaks, will check again in the morning.
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