# Latching Solenoid Gas Valves



## TPC101 (May 5, 2009)

I've inquired to several different Hearth enthusiasts what the layman's terms definition of a latching solenoid  gas valve system is, but it isn't sinking in. Can anyone out there in Hearthland tell me what the features/benefits of this gas valve system are?? Thanks a ton.


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## R&D Guy (May 6, 2009)

I've worked with latching solenoids for some of the older remote control systems once offered.  Its just another type of regulator and allows you to electronically adjust the flame level (benefit) verses manually (by hand) turning the flame up and down at the valve.  It works by using electricity to charge a magnet which in turn moves a metal pin inside the regulator allowing more gas to flow to the burner.  

The counter force on the pin is typically a spring and by increasing or decreasing the amount of power to the magnet you can create different flame levels.

The drawbacks are many in my experience 

- The solenoids I've worked with default to the lowest setting without power.  So during a power outage a consumers fireplace burns on low when they need the alternative heat most unless a backup power system is designed/purchased.

- Solenoids aren't very accurate/repeatable when you try an vary the settings between full high and full low.

- Solenoids can give off a high pitch hum.  

In general the hearth industry has moved away from latching solenoids and moved to more accurate stepper motor.  A stepper motor is more like the kind you'll find on a printer and some valve mfg's allow you to digitally control the settings/position you want between high and low for a very accurate and repeatable/reliable product.


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