AprilAire ViewStats

vining

Has anyone ever a noticed a particulartly odd occurrence where the Stats will change their mode to OFF 3-5 seconds after changing them to either Heating, Cooling or Auto mode? I know there's a feature built into the Stats that will basically allow a user to change temperature for a deifine period of time and then after that time passes it reverts to the previous setting but I checked every option and nothing is set and there's nothing for reverting or changing the mode..

The only thing these 3 Stats have in common is that they are all in the bioler room and use remote temp sensors for room sensing. The rest of the Stats are through out the house and some have remote sensor while others do not.

Since the 3 problematic Stats are in th eboiler room which is pretty hot is possible these guys are sensing the excessive boiler temp and running a safety system off shutdown based on the temperature sensed with the on Stat thermister. They still read and display the remote sensor as they should but only these 3 want to shut off all the time. The room probably runs around 105+ degrees.


Oh and of course I checked notifications to verify that the system isn't sendng and mode changing and even with the set back programming module I'm running it doesn't change mode only set points. I'll push the button to set it to COOL and I'll get the response saying set to cool and then with out anything else being set to it 3-5 seconds later I'll get a string telling me it's now set to off. Very odd.

John Gonzales

I've never seen that happen on any of our installations before. Have you tried taking the communications off of the thermostat and just running it in standalone mode? If it's still happening without the control system attached then it's probably an issue with the thermostat. The operating range of the thermostat is listed at 32-99 degrees Fahrenheit. I've never seen them switch off, but I would hit one of the other ones with a blowdryer to see if it will turn off if the temp hits over 99.

--John

ericmedley

We've put in a ton of them. I classify them as being gear that is, "very good when it's good but awful when they're not." Most of them are rock solid and work fine. But occasionally there will be a unit that is just flaky and unpredictible. It's nothing that is a show stopper but is mildly annoying and hard to pinpoint.

We've just gotten in the habit of keeping a few around and just replacing flaky units rather than do a ton of trouble-shooting that usually yields no definitive answers.

dcpere

I have integrated a lot of these units in various locations, configurations and environments.
One thing I found is if the temperature is too high (usually above ~95' F) these will behave very odd.

Of course they do not all react at the same temperature, and some do not even get affected until a much higher level.

Once the troublesome units were moved to a cooler location, they worked exactly as intended.
I would only recommend locating these in environments well inside the stated operating range.

vining

John Gonzales

Have you tried taking the communications off of the thermostat and just running it in standalone mode?

Not yet. I have to wait until I'm back onsite since I won't be able to see what they're doing then. I doubt it would make a difference since notifcations doesn't show anything going out and I have nothing in my code that changes the mode other than a push of the mode button. The button push toggles through all the modes so if it were somehow doing a push, 1st I would see it but it would also step through all the modes and it always goes straight to OFF.

dcpere wrote:

I have integrated a lot of these units in various locations, configurations and environments.
One thing I found is if the temperature is too high (usually above ~95' F) these will behave very odd.

That's the kind of odd behaviour I'm thinking since it's really the only common denominator.

I wonder if snipping the onboard thermistor would be worth a shot. Actually calling AprilAire should be my first course of action to see if there's a known documented condition.

DHawthorne

It's probably not so much that the temperature it is sensing is causing the issue as the components are just getting flaky from running past their operating parameters. So I don't think snipping the thermistor will help.

vining

Email response from AprilAire TS:

Thank you for contacting us regarding your Model 8870 Communicating Thermostats. The 8870 has a high temperature cut out, if the on-board sensor detects a temperature above 90 F it goes into OFF mode. Since the thermostats are located in the boiler room this likely to occur quite often. The fix is to cut ONE of the legs of the on board thermistor. The attached .pdf shows which leg to cut. Make sure you understand which leg to clip before doing this. Please call or e-mail with any questions

So anybody with TStat's in a boiler room or any other hot room and experiencing similiar problems this should be the solution.

Image attached:

Joe Hebert

vining wrote: »

So anybody with TStat's in a boiler room or any other hot room and experiencing similiar problems this should be the solution.

Good to know. Thanks vining.