Will a programmable T-stat alleviate this situation?

OK, possibly a stupid question...

Now that some colder weather is here, my P68 is cranking up quite a bit more to suit my heating requirements, particularly at night. Being the space heater that it is, by the time it starts calling for heat, it ends up running for a while as the cooler air upstairs gets displaced. It'll be 72/70 during the day and after a night of the stove cranking a bit, I'll wake up to 75-69. The colder the nights are, the greater the differential. I have a fan at the base of my stairs blowing a decent amount of air towards the stove, which has always helped immensely with the differential. I didn't have this issue nearly as bad with my P38, but the 68, at this point in the heating season, is relatively oversized for my application.

I'd rather not mess around with more fans, so I'm thinking a programmable thermostat is a good way to compensate for the temp swings. By setting it to ramp up from 72 to say 73-74 from 7-9PM, would I be smoothing out the temps, or just delaying the inevitable by "moving" the time at which the greatest differential occurs?

The house is a 2400' colonial.

Any advice?

daffonce said:

are you running room temp or stove mode? I find my stove does the best if i leave it in room temp, no figiting with it to compensate for more heat at night. i also feel that it evens out more if i then switch it to manual once it gets a bit colder out.

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I always have my stove in "room temp" mode.

hyfire said:

Maybe not you need a t stat that you can adjust the temperature swing or differential, my wifi is adjustable to .5 to 2.5 degrees.

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Yes, I would get one with an adjustable differential. I think the Harman probe/board is setup with a 1 degree differential, but that's not cutting it.

It's a fairly large space I'm heating and I'm not expecting miracles from installing a programmable one, just hoping to "trick" the stove a bit.

Micmann said:

I might be wrong, but i think harman's temp sensor is just a sensor. Not a switch. It gives the temp reading to the board and the board makes the adjustment. If you jump the sensor temrminals I don't believe it ramps up the stove like it would on a furnace. If this is where you are thinking of wiring in the thermostat and it is only a sensor than a thermostat will not work to turn up the stove. Then again I may not be picturing your installation correctly.

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I believe the tstat is connected through 1 wire of the probes pair. The stove is set WAY
above the stats max desired setting and left on "room temp" mode. At least that's what I understand so far. Haven't got to that point yet.

daffonce said:

I would think moving the sensor a bit might help. maybe it is getting heat soaked from the stove and turning off the stove before it kicks out enough heat to heat the upstairs.

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That's possible. It does a very good job during the day, but with the typical NE weather this time of year, the outside temp swings exacerbate the issue. Never seen more than 1 degree of temp drop on the first floor dino juice stat, so the probe is effective and working properly. Like I said earlier, I think when the stove does ramp up, it displaces all the colder air from upstairs. In the process of playing catch-up, the stove overheats the first floor.

I know I'm fighting the inherent limitations of using a space heater to heat the entire house, but instead of allowing the stoves limited thermostat capabilities to run the show, I'm hoping to integrate a bit more intelligence into things.

ETA- My stove is in manual ignition mode. If I left it in auto, it would most definitely shut down and make matters worse.

ETA- IMO, moving the probe further from the stove more will only cause me to have to change the temp setting on the stove. I wouldn't think it would do anything to eliminate the temp swings as the stove will still be heating the same amount of air and the probe would still see the same dynamics of the air currents in the house. No?

But the question remains, would installing a programmable t-stat mitigate the "space heater" effect of my stove, or am I wasting my money?

I see lots of peeps adding thermostats to their stoves, but it seems like it's for a different reason than what I intend to accomplish. Seems like most people are installing programmable versions so they can lower the heat when they're not at home, and likely aren't encountering the problem I'm trying to eliminate.

I can't be the only one in a 2 story house with this issue.

SmokeyTheBear said:

Move more air in your convection loop.

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Trying to avoid that, but it certainly seems like the only solution. I recently swapped out one of those small square black stove fans for a desktop fan. Helped greatly while on low. Maybe I'll just have to get used to putting it on high on the way up to bed.

May try reinstalling the small one on the stairway overhang area, blowing upwards.

hockeyfan said:

I installed a tstat for 2 reasons: the one you've mentioned, and also to stop from running up and down the stairs every so often to adjust the stove because it was either too hot or too cold upstairs. Having the temp sensor upstairs and controlling the call for heat from there eliminated the problem of having to adjust the dial on the stove all of the time. In this way, I don't see a temperature differential between the adjacent rooms upstairs and downstairs of more than a degree (although the more remote rooms certainly see a little more temp differential).

The key is to have the temp sensor upstairs (but not too far away from the stove either). I think that would lessen the temperature differential when the call for heat is from the upper floor.

However, I'll caution that this is what I've experienced with my particular floor plan (with open staircase), and it works for me. Another floor plan might produce a different result.

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My stairway is only open on the bottom 1/3 on one side. Almost certain if I put the stat upstairs, I'll still have the same issue. Its not a lack of stove output, its a lack of airflow.

Might look into finding a long squirrel cage style fan, like what's used as a convection blower in DV fireplaces, to install in the stairway overhang area. A decent amount of internet searching has only turned up the "bare" blower. Nothing inside any sort of a decent looking enclosure. I suppose I could make something.

I was leaning that way for 2 reasons. First, I think it could be easier to make it look decent. The right enclosure could make it look factory-ish, almost like a small split AC unit. The second, and far more important reason, IMO, is the width of the squirrel style unit. I think it will make a much smoother, and wider, air current and cause minimal disruption to the natural flow of air up into that area of the stairwell. I tried a small Honeywell "turbo" style fan last year and it actually DECREASED the temp upstairs. I think laminar air flow is key.