Furnace has me perplexed

[Gordon Eyre]

My forced air furnace has me perplexed. I have my programmable thermostat set to maintain 72 degrees during the day time and to drop to 65 degrees at bed time. Every thing works fine except when the morning comes and the furnace should kick on at 7:00 am. It does not come on and nothing I do seems to make it come on until an hour or two later. I thought that my thermostat was faulty and so I bought a new one. The new thermostat is an expensive Nest brand and the same thing happens. Turning up the control to a higher level does not make the furnace come on. It is like the furnace has a mind of its own. Sure enough, about an hour later the furnace came on.

My wife likes to shower in the morning and the room is cold (65 degrees) and she is getting ticked. Any thoughts or ideas before I bite the bullet and call a repairman?

[Myk Rian]

I can only think of the time being off an hour, (probably been checked) or another programmable thermostat in line someplace.

[Gordon Eyre]

I can only think of the time being off an hour, (probably been checked) or another programmable thermostat in line someplace.

I do have two separate furnaces and two thermostats but they are totally separate from each other. Also, the one hour is not sacred as the start delay varies by 1 to 3 hours. It will eventually come on but making manual changes to the thermostat will not force it to come on. I have ensured that the thermostat is on Mountain Standard time which is where I live.

[Ken Fitzgerald]

Gordon.....can you hear the igniter trying to light the gas when it is supposed to come on?

We had a problem over a year ago with our gas furnace. The igniter would try to light the flame but couldn't. You would hear a repeating clicking noise as the piezoelectric igniter attempted to light the flame. We had to have a control board replaced.

[Wade Lippman]

Does it hold at 65, or drop lower? It it can hold at 65, then nothing in the furnace would stop it from going to 71; the furnace doesn't know what the thermostat is set at.

[Prashun Patel]

is it exactly an hour or two or three, or is it just some random time later?

What temperature is the thermostat reading at 7:00am and then when it finally turns on? I cannot tell if your thermostat is in your bathroom where you are measuring 65 degrees.

What happens when you set the thermostat to turn on at 6:00am?

What happens when you set the DAY temp super high like to 76-78 degrees?

[George Bokros]

Gordon Pm sent

[Gordon Eyre]

Gordon.....can you hear the igniter trying to light the gas when it is supposed to come on?

We had a problem over a year ago with our gas furnace. The igniter would try to light the flame but couldn't. You would hear a repeating clicking noise as the piezoelectric igniter attempted to light the flame. We had to have a control board replaced.
Thanks Ken, that is a good suggestion. I can not hear the igniter but will suggest that to the repairman if I decide to call him.

[Gordon Eyre]

Does it hold at 65, or drop lower? It it can hold at 65, then nothing in the furnace would stop it from going to 71; the furnace doesn't know what the thermostat is set at.

It will hold at 65

[Alan Rutherford]

If 2 different thermostats got the same (non) result the problem must be elsewhere but I'll pass on some comments relative to the Nest anyway. It's a marvelous of piece of technology but the only reason we have it is that the local electric coop gave it to us. Never found out why.

Tip #1: It's far easier to program and manipulate from a computer, once you have that set up. In your case, that would be the easiest way to see what many of the program settings are or to change them. After you have it programmed, consider disconnecting it from the internet unless you like the idea of Google knowing even more about you than they already do.

Tip #2: The Auto-Schedule feature means it updates its programming every time you make a manual change. Drove me nuts until I realized what it was doing and turned that feature off.

[Gordon Eyre]

is it exactly an hour or two or three, or is it just some random time later?

What temperature is the thermostat reading at 7:00am and then when it finally turns on? I cannot tell if your thermostat is in your bathroom where you are measuring 65 degrees.

What happens when you set the thermostat to turn on at 6:00am?

What happens when you set the DAY temp super high like to 76-78 degrees?

1. Random
2. 65 degrees (set), Varies (actual)
3. Nothing, it does not start the furnace
4. Nothing (if done in the early morning), later in the day it works fine.

[Gordon Eyre]

If 2 different thermostats got the same (non) result the problem must be elsewhere but I'll pass on some comments relative to the Nest anyway. It's a marvelous of piece of technology but the only reason we have it is that the local electric coop gave it to us. Never found out why.

Tip #1: It's far easier to program and manipulate from a computer, once you have that set up. In your case, that would be the easiest way to see what many of the program settings are or to change them. After you have it programmed, consider disconnecting it from the internet unless you like the idea of Google knowing even more about you than they already do.

Tip #2: The Auto-Schedule feature means it updates its programming every time you make a manual change. Drove me nuts until I realized what it was doing and turned that feature off.

Tip #1: I use my iPad, works great.
Tip #2: Yes, I am aware of that but haven't decided what to do as yet.

[George Farra]

Gordon,

Does that furnace only get instructions from 1 thermostat? If it is connected to 2 thermostats (2 zones), are you sure that its not the second thermostat that is kicking on the furnace? Does anything reside between the thermostat and the furnace that could be blocking the signal to the furnace?

I have hot water baseboard with 4 zones and have had situations where 1 thermostat called for heat, the zone valve opened but the furnace didn't fire until a second zone called for heat. The culprit in my case was a faulty zone valve. So if your furnace is serving more than 1 zone, check the zone controllers.

Hope you get things running

George

[Jim Huelskoetter]

If a new tstat has the same problem, the furnace is suspect.. I'm not a furnace guy but they have logic that can delay start for a few minutes in some situations. Maybe a component in that control system has failed and causing an extended delay. I'd call a tech because tomorrow it might fail completely.

[John Goodin]

Before a repairman I would clear out all the programming and manually set it for 65. Then in the morning before your wife takes a shower manually adjust it to 72. If you get the same result I'd call the repairman. Then again maybe set it for 69 or 70 tonight so the wife is only a little unhappy.

[Randy Rose]

Gordon.....can you hear the igniter trying to light the gas when it is supposed to come on?

We had a problem over a year ago with our gas furnace. The igniter would try to light the flame but couldn't. You would hear a repeating clicking noise as the piezoelectric igniter attempted to light the flame. We had to have a control board replaced.


I must agree with Mr. Lippman.

I would submit that it`s not a question of IF the furnace will light, but a question of WHEN. After the faulty delay the furnace evidently functions correctly.
If the O.P. had a faulty igniter , the house would not maintain either the 65 degree night setting nor the higher day setting. ( Then again, I fix toilets, not HVAC. )

[Gordon Eyre]

Gordon,

Does that furnace only get instructions from 1 thermostat? If it is connected to 2 thermostats (2 zones), are you sure that its not the second thermostat that is kicking on the furnace? Does anything reside between the thermostat and the furnace that could be blocking the signal to the furnace?

I have hot water baseboard with 4 zones and have had situations where 1 thermostat called for heat, the zone valve opened but the furnace didn't fire until a second zone called for heat. The culprit in my case was a faulty zone valve. So if your furnace is serving more than 1 zone, check the zone controllers.

Hope you get things running

George

Only one thermostat for this furnace.


If a new tstat has the same problem, the furnace is suspect.. I'm not a furnace guy but they have logic that can delay start for a few minutes in some situations. Maybe a component in that control system has failed and causing an extended delay. I'd call a tech because tomorrow it might fail completely.


Before a repairman I would clear out all the programming and manually set it for 65. Then in the morning before your wife takes a shower manually adjust it to 72. If you get the same result I'd call the repairman. Then again maybe set it for 69 or 70 tonight so the wife is only a little unhappy.

I agree; however, some type of erroneous programming could interfere but I have eliminated any problem of this type.


I must agree with Mr. Lippman.

I would submit that it`s not a question of IF the furnace will light, but a question of WHEN. After the faulty delay the furnace evidently functions correctly.
If the O.P. had a faulty igniter , the house would not maintain either the 65 degree night setting nor the higher day setting. ( Then again, I fix toilets, not HVAC. )

Your logic is sound and that is the same conclusion that I came to. A sensor of some type that is affected by temperature is the only conclusion that I have come up with so far.

[Ken Fitzgerald]

Randy...when we had the problem I described earlier, the furnace would light.....you just didn't know when it was going to light. You would hear the igniter try to light for minutes....it would eventually stop......and then later try to start the cycle over again. Eventually it would light the furnace. According to Gordon's post, the delay he's experiencing is random too.

[Randy Rose]

Randy...when we had the problem I described earlier, the furnace would light.....you just didn't know when it was going to light. You would hear the igniter try to light for minutes....it would eventually stop......and then later try to start the cycle over again. Eventually it would light the furnace. According to Gordon's post, the delay he's experiencing is random too.


Can`t argue with that ^
My limited experience has been that if a fault of any type prevents ignition, the board will attempt a set number of "re-starts" before completely locking down for the inevitable "safety factor".
Again, I`m a nut & bolt guy, can`t understand nor diagnose the voodoo of circuit boards. :)

[Pat Barry]

First, I am scratching my head trying to figure out why you have two furnaces. Be that as it may, you should be able to run the thermostat and therefore your furnace manually. Yes? When you run it manually does the furnace work as expected? If yes then you simply are not programming this thing correctly. It has to be that simple

[Randy Rose]

First, I am scratching my head trying to figure out why you have two furnaces.

Can`t speak for the O.P. however the 3 people I know with 2 units have them because they have a large house.
Size or additions makes it more logical to have dual furnaces rather than extremely long ( non efficient) heat runs.

[Tom Stenzel]

Hi Gordon,

Has the furnace worked correctly in the past and the problem recently started? Or is this a new furnace, or a new to you house, and you've never seen the furnace work correctly? Is it possible the first thermostat was miswired, and when you installed the replacement you duplicated the mistake? Although I'm mystified, I can't think of any possible miswiring that would act as you describe.

Since you installed the new thermostat, you know what wires are the ones that tell the furnace to produce. If you jump those two wires together the furnace better start. Or make the 'heat on' connection at the furnace control board. The problem can be sorted out pretty quickly. Check all electrical connections including the ones for the furnace power.

Although there was one time where I found a furnace out because someone managed spike a nail into a wall and into the wire from the thermostat to the furnace...

Wish you luck. It's 12F outside here right now, wouldn't be happy if the furnace decided to have a poltergeist in it.

Edit: Of course immediately after posting here I went to read The Register, and what do I find:

http://www.theregister.co.uk/2016/01/14/nest_foul_up/

Under the headline:

"Owners of Nest's space-age thermostats are boiling with rage after a software update left them frigid – and facing a long process to get the devices back up and running"

Dang.

-Tom

[Gordon Eyre]

If a new tstat has the same problem, the furnace is suspect.. I'm not a furnace guy but they have logic that can delay start for a few minutes in some situations. Maybe a component in that control system has failed and causing an extended delay. I'd call a tech because tomorrow it might fail completely.

Agree.


Before a repairman I would clear out all the programming and manually set it for 65. Then in the morning before your wife takes a shower manually adjust it to 72. If you get the same result I'd call the repairman. Then again maybe set it for 69 or 70 tonight so the wife is only a little unhappy.

Did that and it did not come on.


Gordon,

Does that furnace only get instructions from 1 thermostat? If it is connected to 2 thermostats (2 zones), are you sure that its not the second thermostat that is kicking on the furnace? Does anything reside between the thermostat and the furnace that could be blocking the signal to the furnace?

I have hot water baseboard with 4 zones and have had situations where 1 thermostat called for heat, the zone valve opened but the furnace didn't fire until a second zone called for heat. The culprit in my case was a faulty zone valve. So if your furnace is serving more than 1 zone, check the zone controllers.

Hope you get things running

George

No zones. Will probably call a repairman tomorrow.

[Dan Hintz]

First, I am scratching my head trying to figure out why you have two furnaces.

We have three (four?) zones... two heat pumps (one for the conservatory, one for the upper level), a propane furnace (for the main level), and a pellet stove (for the basement).

A somewhat related story from just yesterday:
Came home to an obvious power outage from earlier in the day... clocks blinking, etc. Did my normal routine, but I noticed the rooms on the upper level were pretty darn warm (warmer than I had felt them before). I figured SWMBO left the doors open and all of the heat from the various heating appliances mentioned above had simply risen. When it came time for bed, the upper-level thermostat said 81 degrees. I keep it at 72 during the night, so this simply wouldn't do. The fastest way to cool the master bedroom down was to open a couple of windows to the 20 degree air outside. Dropped it a few degrees, then went to bed under the assumption it would continue to drop over the next hour or two. Woke up at 2:30 this morning and it was 84 degrees :(

The heater never turned off. Even turning it to cool still had hot (not just lukewarm) air blowing out of the vents. No matter what I did, the fan continued to run and heat continued to flow. I killed the breaker and opened the windows again just to get some rest. I turned the breakers back on this morning and the cool setting seemed to work again... but we'll see when I get home if the upstairs is sweltering hot again. My guess is the power outage (which was probably a flicker) put the system in an odd state, causing the non-stop heating.

The point being, maybe you just need to the kill the breaker for an hour or two to reset the system (take the batteries out of the controller if it runs on them, too).

[Gordon Eyre]

Interesting you should mention that Dan because I did that yesterday and the furnace came on this morning and warmed to 70 degrees before my wife got up. We will see what happens tomorrow. At least I was a hero for today. 😄

[Bob Turkovich]

So...when all else fails, reboot!!???:p

[Prashun Patel]

25% of all IT problems are solved by rebooting. The remaining 75% are solved by either turning on the monitor or hitting num-lock.

[Marty Gulseth]

I'm no expert anymore but offhand, it sounds to me like the furnace. IS the Nest calling for heat? If I recall correctly, the display on the t'stat turns orange when it's calling for heat. I'm not in front of mine to check right at the minute. I too installed a Nest recently after my old programmable croaked. And like Alan mentioned above - I like our Nest a lot better now that I disabled the auto-program feature...

Best wishes! Cold ain't fun...

Regards, Marty

[Myk Rian]

So...when all else fails, reboot!!???:p
Like the OXO toaster I bought Wifey. It boots up when you plug it in. Strange.

[Jim Koepke]

Like the OXO toaster I bought Wifey. It boots up when you plug it in. Strange.

OMG! Just what I need in life, a toaster that knows more than me. Does it have Wi-Fi?

jtk

[Bob Turkovich]

Wait. I was checking this thread on my Ipad and Gordon's reply @ 10:26AM yesterday was blank! I went back to my laptop and there it was!

What do I need to do to my Ipad? Reboot????


PS: When I see stuff like this it makes me cringe about rushing into self-driving vehicles...

[Pat Barry]

Interesting you should mention that Dan because I did that yesterday and the furnace came on this morning and warmed to 70 degrees before my wife got up. We will see what happens tomorrow. At least I was a hero for today. 
So Gordon, are you still a hero today? Was the re-boot the ultimate solution?

[Wade Lippman]

25% of all IT problems are solved by rebooting. The remaining 75% are solved by either turning on the monitor or hitting num-lock.


I spent a half hour trying to log into Etrade today, only to discover my num-lock was off. I wish I had read your post earlier!
Weird thing is that I have done the same thing for 5 years and never had a problem, which is why I didn't think of it.

[Gordon Eyre]

Well Pat, this is now two days in a row where the furnace has come on in the morning. My wife says that two days in a row does not a hero make but maybe next week sometime. :)

[Ken Fitzgerald]

Gordon....maybe you can wear a merit badge today and get your cape next week?;)

[Gordon Eyre]

Ken, I am wearing my merit badge with pride. Three days and counting.

[Ken Fitzgerald]

I am sincerely glad things are going well!