I want to be able to turn on my gas logs automatically whenever an indoor
thermostat is calling for heat AND an outdoor thermostat says the
temperature is below a temperature selected from a range of 25 to 40
degrees F.

I am trying to find a low cost termostat for the outdoor portion of this
system. It can a simple mechanical thermostat with a SPST switch closed
when below set point or a SPDT switch.

Any pointers would be very much appreciated. I have not been able to find
anything on the web.

Thanks!

On 12/13/2010 13:02, wrote:
I want to be able to turn on my gas logs automatically whenever an indoor
thermostat is calling for heat AND an outdoor thermostat says the
temperature is below a temperature selected from a range of 25 to 40
degrees F.

I am trying to find a low cost termostat for the outdoor portion of this
system.

For a cheap way of doing this, consider cannibalizing an old
refrigerator for a thermostat. This may require some additional control
circuitry as a typical refrigerator thermostat contact OPENS when the
temperature falls below the set point.

A few other words of caution: Are the gas logs designed for room
heating? Typically they're just for show. Are they designed for
automatic unattended operation with a pilot safety relay or automatic
ignition with no-flame cutoff? Is there a high limit switch as exists
on heating appliances? These potential dangers, as well as
self-interest protection measures from the HVAC industry, limit the
availability of these devices to the DIY hobbyist market.
--

wrote in message
...
I want to be able to turn on my gas logs automatically whenever an indoor
thermostat is calling for heat AND an outdoor thermostat says the
temperature is below a temperature selected from a range of 25 to 40
degrees F.

I am trying to find a low cost termostat for the outdoor portion of this
system. It can a simple mechanical thermostat with a SPST switch closed
when below set point or a SPDT switch.

Any pointers would be very much appreciated. I have not been able to find
anything on the web.

Thanks!

Look in beer brewing equipment.

Steve

All good points. Thanks.

I did not mention that, in addition to the thermostats, there would be a
switch to select between
unconditionally on
auto (use the thermostats)
unconditionally off (used when unattended)
Yes the gas logs are intended for (and do a great job of) heating
There is low oxyget and CO protection.

Using a refrig thermostat would require a relay and I wonder if I could get
the necessary temp range since it crosses freezing. A refrig shouldn't go
lower than freezing and a freezer shouldn't go higher so they MAY not be
made for the desired range???

On Mon, 13 Dec 2010 15:01:46 -0800, Bob wrote:

On 12/13/2010 13:02, wrote:
I want to be able to turn on my gas logs automatically whenever an indoor
thermostat is calling for heat AND an outdoor thermostat says the
temperature is below a temperature selected from a range of 25 to 40
degrees F.

I am trying to find a low cost termostat for the outdoor portion of this
system.

For a cheap way of doing this, consider cannibalizing an old
refrigerator for a thermostat. This may require some additional control
circuitry as a typical refrigerator thermostat contact OPENS when the
temperature falls below the set point.

A few other words of caution: Are the gas logs designed for room
heating? Typically they're just for show. Are they designed for
automatic unattended operation with a pilot safety relay or automatic
ignition with no-flame cutoff? Is there a high limit switch as exists
on heating appliances? These potential dangers, as well as
self-interest protection measures from the HVAC industry, limit the
availability of these devices to the DIY hobbyist market.

In article ,
wrote:

Omega will sell you a thermostat that can do just about anything you
want but they ain't cheap.

Most of the money goes to pay for production of their slick catalogs.
Omega is a graphic arts company. They buy stuff from real manufacturers,
have it private labeled, and shoot pretty pictures of it. I use Love
Controls for temperature, but there are other good companies out there.
The cost of the things has plummeted in the last 20 years.

On Dec 13, 7:02*pm, wrote:
All good points. *Thanks.

I did not mention that, in addition to the thermostats, there would be a
switch to select between
* * * * unconditionally on
* * * * auto (use the thermostats)
* * * * unconditionally off *(used when unattended)
Yes the gas logs are intended for (and do a great job of) heating
There is low oxyget and CO protection.

Using a refrig thermostat would require a relay and I wonder if I could get
the necessary temp range since it crosses freezing. *A refrig shouldn't go
lower than freezing and a freezer shouldn't go higher so they MAY not be
made for the desired range???



On Mon, 13 Dec 2010 15:01:46 -0800, Bob wrote:
On 12/13/2010 13:02, wrote:
I want to be able to turn on my gas logs automatically whenever an indoor
thermostat is calling for heat AND an outdoor thermostat says the
temperature is below a temperature selected from a range of 25 to 40
degrees F.

I am trying to find a low cost termostat for the outdoor portion of this
system.

For a cheap way of doing this, consider cannibalizing an old
refrigerator for a thermostat. *This may require some additional control
circuitry as a typical refrigerator thermostat contact OPENS when the
temperature falls below the set point.

A few other words of caution: *Are the gas logs designed for room
heating? *Typically they're just for show. Are they designed for
automatic unattended operation with a pilot safety relay or automatic
ignition with no-flame cutoff? *Is there a high limit switch as exists
on heating appliances? *These potential dangers, as well as
self-interest protection measures from the HVAC industry, limit the
availability of these devices to the DIY hobbyist market.- Hide quoted text -

- Show quoted text -

How about an old mechanical thermostat, perhaps you can change it's
orientation to cover your desired range. Or remove the insides and
play around with another mount. The bimetal spring should continue to
contract and expand across the freezing mark.

Vented gas logs are not particularly efficient but if you have a fan
in them they do make some heat. Unvented, well I wouldn't use those
myself.

I don't have any problems buying anything other than complete furnaces
or acs from the local hvac supply houses. Just know what you want
before you walk in.

On 12/13/2010 3:02 PM, wrote:
I want to be able to turn on my gas logs automatically whenever an indoor
thermostat is calling for heat AND an outdoor thermostat says the
temperature is below a temperature selected from a range of 25 to 40
degrees F.

I am trying to find a low cost termostat for the outdoor portion of this
system. It can a simple mechanical thermostat with a SPST switch closed
when below set point or a SPDT switch.

Any pointers would be very much appreciated. I have not been able to find
anything on the web.

Thanks!

Google differential thermostat. Good luck with low cost.

LdB

On Mon, 13 Dec 2010 15:01:46 -0800, Bob wrote:

I want to be able to turn on my gas logs automatically whenever an indoor
thermostat is calling for heat AND an outdoor thermostat says the
temperature is below a temperature selected from a range of 25 to 40
degrees F.

I am trying to find a low cost termostat for the outdoor portion of this
system.

On Dec 13, 7:02*pm, wrote:
All good points. *Thanks.

I did not mention that, in addition to the thermostats, there would be a
switch to select between
* * * * unconditionally on
* * * * auto (use the thermostats)
* * * * unconditionally off *(used when unattended)
Yes the gas logs are intended for (and do a great job of) heating
There is low oxyget and CO protection.

Using a refrig thermostat would require a relay and I wonder if I could get
the necessary temp range since it crosses freezing. *A refrig shouldn't go
lower than freezing and a freezer shouldn't go higher so they MAY not be
made for the desired range???

So is this indoor thermostat dedicated to just the gas logs, or is it
controlling
your primary heating system and you wish to use it to control this
additional
heating source as well?

Typically the low voltage thermostats require using some sort of relay
to
control line voltage motors and starters in furnaces, you are just not
seeing
them because they are on the control board...

Your description of the "control switch" is a standard HOA (Hand/Off/
Auto)
contactor controller which will involve the use of a relay and a
contactor to
control said devices with a standard low voltage wall thermostat...

How to do this using a "low cost" outdoor thermostat? Good luck...
Weather responsive heating controls are not known for being cheap...

~~ Evan

The gas logs provide a pair of contacts. Shorting the contacts together
will turn on the logs. This is powered by a thermocouple having one end in
the flame. Therefore, the circuit is very low voltage & very low current.
The contacts of any thermostat could be used in this circuit with no
problem.

The overall idea is to keep the heat pump from running when the outside
temp is low enough to make using the heatpump more expensive than using the
propane logs.

I would have a separate indoor thermostat for the logs set a degree or two
higher that the thermostat for the heatpump. As the house temperature
falls, the gas log thermostat whoud start calling for heat. If the outside
thermostat says it is cold enough out there, the gas logs would come on
raising the temperature in the house & thus preventing the heatpump from
coning on (unless the logs couldn't produce enough heat - but that hasn't
been a problem).

If iw was too warm outside for the outdoor thermostat to close, then the
house temperature would continue to fall another degree or two and turn on
the heat pump.

Really a simple arrangement. Any thermostat with the proper temperature
range should work fine. I could enclose it in a waterproof plastic bag if
I had to.

On Tue, 14 Dec 2010 22:30:15 -0800 (PST), Evan
wrote:


So is this indoor thermostat dedicated to just the gas logs, or is it
controlling
your primary heating system and you wish to use it to control this
additional
heating source as well?

Typically the low voltage thermostats require using some sort of relay
to
control line voltage motors and starters in furnaces, you are just not
seeing
them because they are on the control board...

Your description of the "control switch" is a standard HOA (Hand/Off/
Auto)
contactor controller which will involve the use of a relay and a
contactor to
control said devices with a standard low voltage wall thermostat...

How to do this using a "low cost" outdoor thermostat? Good luck...
Weather responsive heating controls are not known for being cheap...

~~ Evan

Thanks! I didn't see anything like this on Love Controls' web site, but I
sent them an email asking if they could provide one or suggest another
source. I noted that they sell thermocouples and my gas log circuit is
powered by an alreadt existing thermostat, so perhaps they can help.

On Tue, 14 Dec 2010 03:11:17 -0800, Smitty Two
wrote:

In article ,
wrote:

Omega will sell you a thermostat that can do just about anything you
want but they ain't cheap.

Most of the money goes to pay for production of their slick catalogs.
Omega is a graphic arts company. They buy stuff from real manufacturers,
have it private labeled, and shoot pretty pictures of it. I use Love
Controls for temperature, but there are other good companies out there.
The cost of the things has plummeted in the last 20 years.

I thought about that and may still go that route. I do not have access to
an old thermostat, so I would have to buy one. I kind of hate to do that
since I am not sure I could make it work.

For a cheap way of doing this, consider cannibalizing an old
refrigerator for a thermostat. *This may require some additional control
circuitry as a typical refrigerator thermostat contact OPENS when the
temperature falls below the set point

On Dec 13, 5:02*pm, wrote:
I want to be able to turn on my gas logs automatically whenever an indoor
thermostat is calling for heat AND an outdoor thermostat says the
temperature is below a temperature selected from a range of 25 to 40
degrees F.

I am trying to find a low cost termostat for the outdoor portion of this
system. *It can a simple mechanical thermostat with a SPST switch closed
when below set point or a SPDT switch.

Any pointers would be very much appreciated. *I have not been able to find
anything on the web.

Thanks!

Your thermostat may already have what you need. Mine did. My heat pump
had a second set of contacts that could control an alternate heat
source when the outside temp got down to about 40F. For me this also
limits heating to the core of the house which saves me money and I
like sleeping in a cold bedroom with lots of quilts on the bed.

Jimmie