My new wall heater has a gas valve that is thermostatically
compatible. The most common thermostat for this heater is
called a "microvolt" thermostat. It apparently get its
microvolts from something heated by the pilot light.

What I can't seem to get my head around, is how can such a
small amount of power manage to horse-open the rather high
flow gas valve?

--
croy

croy wrote:
My new wall heater has a gas valve that is thermostatically
compatible. The most common thermostat for this heater is
called a "microvolt" thermostat. It apparently get its
microvolts from something heated by the pilot light.

What I can't seem to get my head around, is how can such a
small amount of power manage to horse-open the rather high
flow gas valve?

Him
No manual to read? My guess is the micro current triggers power to the
valve coil. Definitely it can't directly control the valve.

http://wiki.answers.com/Q/How_do_mil...as_valves_work

"croy" wrote in message
...
My new wall heater has a gas valve that is thermostatically
compatible. The most common thermostat for this heater is
called a "microvolt" thermostat. It apparently get its
microvolts from something heated by the pilot light.

What I can't seem to get my head around, is how can such a
small amount of power manage to horse-open the rather high
flow gas valve?

--
croy

On 12/10/2011 10:34 PM, croy wrote:
My new wall heater has a gas valve that is thermostatically
compatible. The most common thermostat for this heater is
called a "microvolt" thermostat. It apparently get its
microvolts from something heated by the pilot light.

The something is a thermocouple. It is actually millivolts not
microvolts. The common name for that system is "powerpile" which might
be a Honeywell trademark. We used to have that system on an old steam
boiler. It worked well and as long as the natural gas flowed there were
no worries about power outages.


What I can't seem to get my head around, is how can such a
small amount of power manage to horse-open the rather high
flow gas valve?

The valve is designed so that only a small amount of energy is required
to open it.

On 12/10/2011 10:34 PM, croy wrote:
My new wall heater has a gas valve that is thermostatically
compatible. The most common thermostat for this heater is
called a "microvolt" thermostat. It apparently get its
microvolts from something heated by the pilot light.

What I can't seem to get my head around, is how can such a
small amount of power manage to horse-open the rather high
flow gas valve?

It uses a pilot generator to make electricity which powers the coil on
the valve. The down side is that it generally takes a while to operate,
unlike a 24 or 120 volt coil valve

On Dec 11, 9:00*am, RBM wrote:
On 12/10/2011 10:34 PM, croy wrote: My new wall heater has a gas valve that is thermostatically
compatible. *The most common thermostat for this heater is
called a "microvolt" thermostat. *It apparently get its
microvolts from something heated by the pilot light.

What I can't seem to get my head around, is how can such a
small amount of power manage to horse-open the rather high
flow gas valve?

It uses a pilot generator to make electricity which powers the coil on
the valve. The down side is that it generally takes a while to operate,
unlike a 24 or 120 volt coil valve

Sounds like it's the same type of system used on most
water heaters that also don't have any external power
source to open the gas valve.

On Sat, 10 Dec 2011 22:26:53 -0700, Tony Hwang
wrote:



croy wrote:
My new wall heater has a gas valve that is thermostatically
compatible. The most common thermostat for this heater is
called a "microvolt" thermostat. It apparently get its
microvolts from something heated by the pilot light.

What I can't seem to get my head around, is how can such a
small amount of power manage to horse-open the rather high
flow gas valve?

Him
No manual to read? My guess is the micro current triggers power to the
valve coil. Definitely it can't directly control the valve.
Wrong - it most definitely DOES directly control the valve as
microvolr controlled gas appliances are the only ones that will work
with the power out and no batteries required.

On 12/11/2011 9:05 AM, wrote:
On Dec 11, 9:00 am, wrote:
On 12/10/2011 10:34 PM, croy wrote: My new wall heater has a gas valve that is thermostatically
compatible. The most common thermostat for this heater is
called a "microvolt" thermostat. It apparently get its
microvolts from something heated by the pilot light.

What I can't seem to get my head around, is how can such a
small amount of power manage to horse-open the rather high
flow gas valve?

It uses a pilot generator to make electricity which powers the coil on
the valve. The down side is that it generally takes a while to operate,
unlike a 24 or 120 volt coil valve

Sounds like it's the same type of system used on most
water heaters that also don't have any external power
source to open the gas valve.

It is. I don't see them on conventional heating systems anymore. They
were great when the power went out. Once the thermostat called for heat,
it took a minute or so for the valve to open