What's the difference in programmable thermostats?

[krattigan]

Curious what is the difference in a cheap $25 dollar honeywell as compared to a $100 Sky tech etc.. I have hooked up a honeywell to my nps 45 and still running some tests on it. It seems to be turning on when programmed then it looks as if the low limit switch trips (#3 flashing light) Have already changed the low limit and just replaced the circuit board. Did I mention this stove is brand new . Any suggestions are greatly appreciated!

 

[briansol]

my 22 dollar thermo runs my stove fine. Mostly you pay more for a pretty interface, more prgrams, or wireless functions.

Sounds like you have a bigger issue....

I would suggest returning the thermo and try a 2nd one just to be sure, and also make sure it's been wired up correctly.

 

[tjnamtiw]

The thermostat, any thermostat for our stoves should be nothing but a switch to tell the stove to burn pellets or not. Like briansol said, you have something else going on. I use a $25 Ritetemp on one stove and a wireless SkyTech on the other only because of the install locations. When getting a thermostat, the only thing you want to watch out for is to make sure it has an adjustable 'swing' capability. Many don't. This allows you to adjust how many degrees from the setpoint the temperature will fall or rise before starting or stopping the stove. The RiteTemp 6022 has that capability.
http://www.ritetemp-thermostats.com/60XX/images/6022_operation_guide.pdf

There have been quite a few posts on here from people with Honeywell thermostats who found that their functions did not suit a simple on/off system. Maybe someone with that experience can chime in or can suggest other alternatives than my RiteTemp.

 

[jtakeman]

Are you running the stove on feed setting 1(low)? And what brand of fuel are you using?

 

[whit]

A cheap Honeywell works fine on my stove. Just on an off, with temp settable for 4 defined periods of the day. Are there standard thermostats that put out more than either the set current to signal on, and no current to signal off?

Thermostat placement might be a problem more for some brands than others though, depending on how quickly they shut on/off when the set temperature is reached. Think some intentionally overshoot to avoid having the cycles be too short. If you have one that doesn't overshoot, or overshoots less, and it's too close to the stove, that could cycle the stove too fast to be practical. Maybe some Honeywells, when too close to the stove, do that. Mine's clear across the room, and there's no problem.

 

[tjnamtiw]

A cheap Honeywell works fine on my stove. Just on an off, with temp settable for 4 defined periods of the day. Are there standard thermostats that put out more than either the set current to signal on, and no current to signal off?

Thermostat placement might be a problem more for some brands than others though, depending on how quickly they shut on/off when the set temperature is reached. Think some intentionally overshoot to avoid having the cycles be too short. If you have one that doesn't overshoot, or overshoots less, and it's too close to the stove, that could cycle the stove too fast to be practical. Maybe some Honeywells, when too close to the stove, do that. Mine's clear across the room, and there's no problem.

Thermostats don't put out any current. It is simply a switch closure. If the batteries are weak, the relay, be it mechanical or electronic, won't close. If you use rechargeable batteries, that's only 2.5 V for two instead of 3.0. That might also be a problem for some thermostats.

The second paragraph is where the 'swing' adjustment that is available on some models comes into play, allowing the temps to go higher before shutting off and lower before turning on. Many here like that option.

 

[Don2222]

Curious what is the difference in a cheap $25 dollar honeywell as compared to a $100 Sky tech etc.. I have hooked up a honeywell to my nps 45 and still running some tests on it. It seems to be turning on when programmed then it looks as if the low limit switch trips (#3 flashing light) Have already changed the low limit and just replaced the circuit board. Did I mention this stove is brand new . Any suggestions are greatly appreciated!

Thermostats with a "Swing Temperature" Setting are recommended for pellet stoves since they allow the wood pellet stove to cycle down and then cycle back up. A regular thermostat may work ok on some stoves but may be trouble on other stoves!

The LUX 9000TS at Lowes is not very expansive and has the "swing temp" setting!

See this thread for lots of T-Stat info.
https://www.hearth.com/talk/threads/80457/

 

[whit]

Thermostats don't put out any current. It is simply a switch closure.

Yes. When the switch closes they pass through the current, which is taken in on one side, and put out on the other. At least that's all simple ones do. I know some do more complex signaling, but not their methods for that. Do they modulate the current going through, to add other signaling besides on/off? Or do they have separate circuits for the other signals?

For most pellet stoves, the on/off switching is all they understand. The Quad AE's for instance do more than that from the thermostat. My Santa Fe doesn't.

 

[krattigan]

Thanks for all the input,... I am burning Comfort/Cubex Pellets and have had it running on a heat3 fan 2 or heat 3 and fan 3 setting. When in Manual the stove runs fine so something is up with the thermo i have or the control board receiving the info, although i just replaced the control board 4 days ago.
* I have also noticed that when I switch the stove from manual to Thermo or auto mode the green power light begins blinking. I also noticed this blinking green light after the stove had been in thermo setting for a while. I am curious as to what is prompting this light. Thanks

Also I set my thermostat temps in extremes for example Wake at 80 Leave 40 Return 80 Sleep 40 So that running in auto mode the stove should shut off after not being called for heat after an hour.
The termo setting is supposed to get the stove up to the desired temp then kick back down to lowest burn settings, This is also not communicating with the thermo as it stay burning at the same setting it was previously burning in/started up at. Thanks for any input. I have had this stove for about a month now and have had nothing but problem after problem with lots of unsuccessful troubleshooting.

 

[SmokeyTheBear]

A more important question is exactly what make and model of stove are you talking about?

 

[krattigan]

Napoleon NPS 45 freestanding

 

[SmokeyTheBear]

That green light that flashes is indicating the stove is either in start up or shut down mode. This is in response to the t-stat calling for heat (until the stove satisfies proof of fire) or the stove is shutting down because the t-stat is saying I'm hot enough.

 

[SmokeyTheBear]

About running on a t-stat, some controllers can only change modes when the are powered off the mode switch changed and power reapplied (I haven't gotten to that part of your stoves manual yet).

That t-stat is only a switch, if there is short in the t-stat wires it will act as a continuous call for heat, if there is a break it will act as being continuously at temperature.

When the board was replaced was the jumper removed and the t-stat wires reconnected.

 

[krattigan]

Thanks for clearing that one up! On to why it is still shutting down sometimes..

 

[SmokeyTheBear]

About attempting a 40 degree recovery, you had best have a very tight extremely well insulated house that isn't large or a very large dose of patience. Pellet stoves do not approach the heat recovery capabilities of a central heating system.

What code is being shown when it shuts down?

 

[krattigan]

I am getting # 3 flashing, I have already replaced the low limit switch.... Just ran a test 10 am set for 90 10:15 set for 40. Stove was off before 10 am...turned on as it was programmed at 10 am, after 10:15 had temp set for 40, stove began to go onto shutdown mode (no longer calling for heat) stove shutting down, went outside came back in and stove just has the fan going a few unburned pellets in the bottom and #3 light flashing. Why do you think it ended up doing this? Thanks !

 

[SmokeyTheBear]

I would suggest you contact Napoleon and ask them how long the start up cycle clock is and give them exactly what you just told us.

ETA: That code should self clear and not knowing the actual programming used, may not even be a problem.

 

[jtakeman]

PM member geek, He has the same stove. Should be able to assist you as he has his NPS 45 on the Skytech remote stat.

As for the start up timer its 5 minutes. But it really sounds like your stat wire isnt connected properly or it has a broken wire in the circuit.

 

[fidiro]

How far from stove is the thermostat installed? Is it to close to a heat source of any kind that makes it reach the shut off heat setting too soon? Don't know if that would make a diffence for your stove but my thermo is right behind my stove on wall and if I don't set it to the max temp for morning program it may shut down only to re-ignite a few minutes later and if yours does the same thing it may not be getting hot enough for the low switch to pick up enough heat to stay on, IDK.

I'm using the cheaper digital Honeywel(I believe it was $20 @ HD) but again mine is a dinosaur and really can't comment much.

 

[krattigan]

it's about 6/7 feet from stove, it's running on a 100 ft wire (new) not sure if that makes a difference. I do have my temps set to extremes...test 10 am set for 90 10:15 set for 40. Stove was off before 10 am…turned on as it was programmed at 10 am, after 10:15 had temp set for 40, stove began to go onto shutdown mode (no longer calling for heat) stove shutting down, went outside came back in and stove just has the fan going a few unburned pellets in the bottom and #3 light flashing.
****Had stove programmed to come back on at 11:15, set temp to 90, didn't come back on at 11:15 #3 light still flashing...then at 11:30 just came back on?

 

[fidiro]

It sounds like it only have it set to run 15 minutes and that is probably not enough time to heat things up enough for the limit switch to pick up heat. You should run it for at least 45 minutes to see what happens. Good luck

 

[imacman]

It sounds like it only have it set to run 15 minutes and that is probably not enough time to heat things up enough for the limit switch to pick up heat. You should run it for at least 45 minutes to see what happens. Good luck

Agreed....15 minutes is going to "confuse" the stove....run at least 1 hour before trying shutdown time, and then another 30-45 minutes to try restarting.