Mt. Vernon AE T-stat program issues

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ckiefer

New Member
Jan 2, 2011
4
Northern VA
Hi all,

Just installed my Quadra-fire Mt. Vernon insert last week. Overall the unit runs real well, but I'm having problems getting the the temperature program to run correctly. The unit is programmed using the M-F and S-Su data fields. When looking into the other daily fields (i.e. M, T, W, etc.) the temps and set points have transposed here. The unit is currently set on "Automatic". The problem is the thermostat seems to "forget" when to change the temp at various set points. Here is a specific example:

It's Sunday morning. The S-Su program is currently set to the following:

Wake 6:15am 75
Day 8:45am 75
Evening 6:15pm 75
Night 11:30pm 72

The program calls for the unit to drop to 72 degrees at 11:30pm on Sat night, then rise to 75 at 6:15am on Sunday. Prior to 11:30pm on Saturday it was set to maintain 75 degrees and was doing so before I went to sleep (I did not stay up last night to see what happened at 11:30pm. When I awoke this morning it unit read "set to 72" at 7:15am. So, sometime between 11:30pm and 7:15am it did change to 72 (though I don't know when), but it certainly did not automatically adjust the temp up to 75 when it was programmed to at 6:15am. I fiddled with the t-stat set point times in an attempt to force the next set point to try and see if it jumped up to 75 at that time. Upon exiting the program again, the t-stat then read "set to 75". As I stated above, it is almost as if the unit "forgets" when to change the temp and it somehow "remembers" when I go back into the program and change things.

Similarly, yesterday morning I went down and it was not reading correctly so I detached the t-stat from the back plate and reinstalled it. Upon doing so, the "set to" temp then read correctly.

Also, the issue seems to occur at any of the 4 programmable daily set points. It is not localized to the "wake" condition.

At this point I can only assume that the unit (either T-stat or controller) is defective, but I was hoping to get some advice from fellow owners. I have searched the internet extensively and have not been able to find any documentation of this happening to anyone else. Is it possible that I am doing something incorrectly? This is a new quad unit....stamped manufactured Dec 2010.

Thanks is advance for your input/response.
 
Congrats on the new MT Vernon AE Insert, your going to love it once you get the hang of running it, also welcome to the forum. :coolsmile:
There have been many improvements made to this stove since I got mine in 2006. The Quads MT Vernon AE thermostats are a little fluky. If you mess with the night settings it wackes out the thermostat next start settings. I would shut down the stove and unplug the unit for a couple of minutes to re boot it. Anytime you mess with the temp settings I have found I have to raise or lower the temp manually and then hit the resume button to get it back on track.
See this post for the night time thermostat issues on the AE. :bug:
https://www.hearth.com/econtent/index.php/forums/viewthread/63962/
 
Thanks, the thread you both posted was the pretty much the only thing I could find on t-stat problems when I was researching my issue. The way I understand it though, I think that's the reverse of what's happening with mine. He would change the temp manually and then it would revert back to the program. That would be just great as far as I'm concerned! :lol: Mine won't maintain the program cycle at all and just changes temperature when it feels like it or when I go in and make some random minor adjustment in the program settings.

I've also noticed that if I stare at the t-stat a while :ahhh: , the time will jump rapidly. For example, it will be 8:10am for a long time and then suddenly change to 8:12am. I'm wondering if it jumps like this over the set point - say going from 11:29pm to 11:31pm without actually reading 11:30pm when the temp should change - maybe that's why it's not following the program?

Over the last couple of days I've tried several suggestions I found in the forum, including Ford's suggestion to manually set the temp and then hit resume. That looks like it's working fine until the next time point when it doesn't follow the program changes.

I'm waiting for the shutdown now to test the reboot theory. Anyone else have ideas?
 
I have not noticed those issues but suddenly, I am experiencing a weird issue where the top left of the t-stat sometimes reads -------- in place of ready, startup, manual high, autolcean, etc. When this happens, it basically stops the unit from properly functioning. This happened last night, for example, and when I got up this morning, the temp was 59 instead of the 70 or so it should have been by then. anybody else experience this? I am wondering if I should do a full reboot as well.
 
Sometimes static electricity can cause these _ _ _ _ _ issues. I would make sure the thermostat wire connections are tight at the stove and thermostat. Unplug the stove and remove the face of the thermostat and check the wire connections at the thermostat and stove terminal block. Reinstall thermostat face and plug stove back in. Some of the earlier units had a wire tie that was too tight on the thermostat wire bundle going to the control board from the terminal block on the stove and Quad was recommending to remove this wire tie. I have had the thermostat do this once when cleaning the stove. When I was vacuuming the stoves fire box floor I was getting shocked from the static electricity build up in the vacuums plastic hose. I now unplug the 120 and 12 connections to the stove when cleaning.
What do you have insert or free standing stove?
 
I have the insert and love it. I did have the vac switch and auger motor replaced this season but it has otherwise been very easy and inexpensive to maintain. I made the mistake of buying 5 tons of cleanfire supreme pellets which burn hot but they have a ton of fines so I need to clean the auger and the tube that runs to the vac switch pretty regularly this season. Which type of pellet setting is best for longest burn cycles before autoclean? I generally have mine set on softwood since the pellets are softwood mix and then run the stove on manual high during this time of year.

I will check the connections next time I shut it down. Hopefully that is all it is. I hope I do not have to replace the thermostat.
 
Softwood will give the longest burn time before auto clean, around 3.2 hours in the highest setting. Next would be sunflower seeds and corn at around 2.4 hours then hardwood at around 2.1 hours. After that wheat runs around 1.8 and utility pellet runs around 1.2 hours. All these run times are in the manual 5 setting and will be longer in the lower settings and on auto.
I have been running mine in sunflower seeds and high elevation and just recently have been trying the auto setting with a 2 degree room temp differential. So far is has been holding the temp swings in the house a little better running it this way. Before that I was using the manual 2,3 or 4 depending on outside temps and a 1.5 degree room temp differential. Running it in high elevation has allowed me to get my flame height settings closer to the 0 setting, before this I was always at -5 to keep the flame height down. I will have to see if the auto setting will keep the house warm in the real cold weather, time will tell.
 
Just wanted to give an update on the OP. I called SunFire (our installer in Martinsburg, WV), and they did a service call to check things out. Replaced the thermostat and BINGO everything worked perfectly. Apparently it was just a defective thermostat. Glad I payed attention to all the posts on here about buying from a reputable and reliable dealer - good service made a potential nightmare headache into an easy fix and didn't cost us a penny. :coolsmile:
 
Glad the new stat is working for you!

I made the original post on that programming issue (https://www.hearth.com/econtent/index.php/forums/viewthread/63962/).

May I ask if yours exhibits the same behavior as mine, in other words, if you change your setpoint after 11:30 PM will it maintain it until the "wake" cycle, or will it revert to the previously programmed setpoint within a few minutes? I'd like to know if QF fixed my issue. If they did, I'll buy a new stat.

If you don't want to stay up until 11:30 you can temporarily change the "night" cycle to something earlier, like 8 PM.

Most if not all the "brains" or the Mt. Vernon are in that wall unit. The problem is that I can find no way to completely reset it to factory defaults. Removing it from the wall and replacing it won't erase the program. I even left the thing unplugged for several months during the summer and it remembered everything. The clock was a little off but other than that, all my program settings remained. This is far too long for memory retention using a charged capacitor, besides, there aren't any big enough on the board. It must store its program memory in EEPROM or something like it.

No settings are stored on the "control board" inside the stove because replacing it with a new one didn't change my program either.

As far as I know the clock time "jumping" a couple minutes ahead once in a while is normal. Ambient temperature is updated at least once a second but I don't think updating the clock is considered a high priority. It may update the time of day at intervals greater than one minute. That doesn't seem to affect anything in particular.

Almost no one seems to use the programmable feature of this stove. I'm glad you understand it - you and I may be the only ones. Even QF was clueless (read my original post).
 
We've been running on manual (med-high or high) since it's been so cold here lately, but I ran the test for you and everything seems to be working properly - no reversion to the program after changing the setpoint after 11:30pm for at least an hour. Maybe it's time to try a new tstat. :)
 
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