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[Shrek1112]

My new OWF was installed with a digital Honeywell. The existing gas furnace has a programmable honeywell also. Is it possible to use a programmable one for the OWF? I don't need to keep the house at 70+ when we are not home for 10-12 hours a day during work and after school sporting events with the children. Also any recommendations on a good one if I can do the switch?

[AirForcePOL]

You can pretty much use whatever thermostat you want.  I have a programmable one but I have never set it up.  I just leave it at 70 all the time. 

[Jwood]

Saving gas is one thing saving a few logs is another I'd leave it set at what you have it and dont worry about it.

[LittleJohn]

A set back thermostatic, would only really work if you have a low-mass (dry) system or air exchanger type system.  Otherwise the reaction time of your system woudl be working against you.

[Shrek1112]

Little john can you expound on this as to the how/why it would work against itself?  Just curious now...

[LittleJohn]

Little john can you expound on this as to the how/why it would work against itself?  Just curious now...

In general it can take easily an hour or more for a radiant slab to have a noticable reaction to a change of the thermostat. 

Lets say you have an inslab application, & assume that the slab is up to temp or near up to temperature before the offset hits.  The next call for heat may not be for hours and by then the slab has cooled off and will; a) take a long time to get back up to comfortable temperature or b) nothing, as there will be enough stored energy in the slab that the house stays at the same temperature.

I typically tell people to wait a day in between messing with the thermostat on the wall; because with an in-slab application it can take that long for the slab to get up to temp and even out.

[Shrek1112]

Okay that makes sense,  I currently only have DHW and forced air application in the house  so would I be okay with a programmable?

[RSI]

If you use a programmable thermostat you need to make sure the backup heat is set lower than the lowest temperature on the OWB thermostat.

If you already had an existing programmable that you liked, just swap the wires so the G from the furnace goes to W in the programmable thermostat and the W goes to the W in the 2nd thermostat. This will make the new thermostat run the gas and needs to be the one with the low setting.

[Jwood]

When I hooked mine up I used one two stage thermostat swapped two wires and that was it. Put my green to w and white to w2 and now the blower kicks on if I get 3 degrees below my set point on my thermostat the inducer fan and gas kick on.

[Shrek1112]

 
Thank you Jwood and RSI, I will give that a try after our 45+ degree weather departs central Michigan and winter decides to arrive.

[RSI]

When I hooked mine up I used one two stage thermostat swapped two wires and that was it. Put my green to w and white to w2 and now the blower kicks on if I get 3 degrees below my set point on my thermostat the inducer fan and gas kick on.

So, if you decide you want the house warmer and turn the temp up 4 degrees the gas kicks on?

[Jwood]

When I hooked mine up I used one two stage thermostat swapped two wires and that was it. Put my green to w and white to w2 and now the blower kicks on if I get 3 degrees below my set point on my thermostat the inducer fan and gas kick on.

So, if you decide you want the house warmer and turn the temp up 4 degrees the gas kicks on?

Glad you thought of that RSI and pointed it out, and yes I believe it would but I have never used the setback function I just don't see the benefit of it when I'm burning wood but that's just me. There are multiple ways to get the furnace running this was my 1 minute hookup later I will get a much better thermostat and re run a 5wire instead of the 4 wire I have.

[Shrek1112]

So if I run it the way JWood described my gas furnace would kick on and burn the propane vs just turning the fan on to blow over the hot water coils?  Am I trying to be to thrifty by saving a log or two by having the programable control the OWF?  If I am off my rocker just let me know, I can take it    . Plus it will save time and energy in my part. 

[RSI]

It depends on the thermostat. I think there are some out there that have adjustable differentials between primary and backup heat. Unless you don't like the looks of two thermostats, it is the simplest to operate and cheapest. Just set the backup lower than the lowest setting on the programmable.

And as I mentioned above, you don't have to have the OWB operate off the 2nd thermostat, you can use the original that ran the gas. You just connect the opposite wires to the 2nd thermostat is the backup gas heat.

[oaky]

I've been running a dedicated programmable thermostat for the owb for years, works great for my wife & myself, program it to turn on the forced air blower an hour or two before getting out of bed. A nice warm morning to wake up to at 76 degrees.