New Rheem Furnace/AC SMOKING

[johnboy77]

Got a New Rheem 95% Dual Stage Furnace and 14.5 Seer R-410A A/C installed with a Honeywell Vision Pro 8000 touchscreen Thermostat.
The Furnace fired up ok and ran for 10 mins. When they turned on the breaker for the A/C lots of smoke billowed out of the vents! Real nasty smelly stuff. Every smoke alarm and detector in the house went off! After working on the problem for 45 mins ... the guys said the Thermostat WHITE Wire was shorting and caused both the Furnance and A/C to run at the same time!
And the smoke was only dust in the vents! They used a spare wire as the white wire and refused to change out the 30+ year old thermostat wire. Since it was after midnight I let them go and called their boss the next day ... they came back and replaced the wire.

So are these guys full of crap or what?
What really caused the nasty smelling smoke?
Any ideas?

[karsthuntr]

oil on the HX that protects it from rusting while in storage. Nothing to worry about.

[amd]

the guys said the Thermostat WHITE Wire was shorting and caused both the Furnance and A/C to run at the same time!
And the smoke was only dust in the vents!

Modern furnaces move much more air than their natural draft counterparts; it probably stirred up a lot of dust.

You got a nice setup - make sure they set the t-stat up to control second stage heat properly. (Many installers just use one wire for heat and jump both terminals at the control board - it will work, but switch to high after a predetermined time whether required or not)

[johnboy77]

It just seemed strange that there was NO smoke when they fired up the furnace and it ran for a GOOD 10 mins ... I only noticed the normal dusty smell you get when first time startup of the furnace after several months not being used. Less than 1 min after putting the A/C breaker on we got lots of smoke.

If truely both Furnace and A/C came on at the same time would this cause any damage? They kept the Furnace going for several minutes while the house filled up with smoke!

[johnboy77]

AMD ...

I'll go check to see if they are using only one wire for heat ... even when I pushed them to go 2 stage. They said it can only be setup that way and the furnace automatically starts at low and then goes high. I checked manual and the default setup has a 12 min delay. They acted like they didn't know very much about the Rheem ... but I suspect they were just lazy and wanted to take the easy way & quickest way on the entire
install. We paid good money and were sold on how great their installers were. I had to be on a constant watch that they followed thru and did a clean neat and safe install.
When I stepped away the guy ran the A/C coolent line under the hot air return duct and hung it from the duct. What an ugly mess ... even when I complained he said it was ok and ignored me when I told him to put it up between the 2X12 floor joist like it was on the old unit. He did have to come back later and move it ... 5 mins cost him 2 hours!
We have good equipment ... if only it's setup properly for optimal effeciency.

I will go thru furnace manual and t-stat manual closely and try and figure it out.


Thanks Guys for your feedback.

[amd]

If the furnace has a W2 terminal it should be connected.

Based on your description, I really doubt that they checked the gas pressure, refrigerant charge, and blower speed.

[BaldLoonie]

Rheem furnaces seem to be bad at smoking on startup and setting off smoke alarms. Usually has a blue tint to the air and does smell. I would hope they are using a 2 stage stat on it, not crippling a nice furnace with a timer

[johnboy77]

Ok ... I think the smoke issue was when the Furnace went to 2nd stage and full fan at 12 mins ... it just so happened that the A/C power was turned on at the same time. The factory default has the P7 furnace board set to go stage 2 after 12 minutes.

During the call-back the Guy replaced the wires and said he setup T-Stat to handle STAGE 2 Heat.

So is the T-Stat / Furnace wiring setup so that the 2 stage furnace works as designed?

I went and checked the T-Stat and furnace wire setup and referenced the Furnace Install manual and T-Stat Installation Manual.

The ACTUAL wiring looks correct:

T-Stat Furnace

RC<->R (RED) - R
W (White) - W
Y (Black) - Y (connects to A/C)
W2 (Orange) - W2
G (Green) - G
O (connects to A/C)

It looks like he went and changed the P7 Furnace Board jumper to NONE for Stage 2 Heat.

BUT ... Only the Time/date info was updated on the T-Stat and all DEFAULT
settings are being used! This means the 170 Setup Function for "SYSTEM TYPE"
is set at (1) "1/heat/1 cool conventional". When I go to the Installer System TEST
Function I can ONLY Test "(1) HEAT and FAN turns ON". It will NOT accept or perform the SECOND STAGE HEAT test!
SO ... We are ONLY getting STAGE 1 HEAT!!!

I changed the 170 Setup Function to "(9) 2 heat/1 cool multistage conventional" and
the 240 Function from "(5) Furnaces of less than 90% efficiency" to
"(3) Hot water systems and furnaces greater than 90%". I then was able to do a Installer Test
"(1) HEAT and FAN turns ON" and the furnace acts JUST like it was before IE: Stage 1.
Also I could now do "(2) Second Stage Heat Turns On" test and the furnace Fan goes to MAXIMUM and I assume Flame goes to Maximum also ... makes a bit of noise and vibration thru the furnace! I wonder if over time this could cause problems due to vibration?

Hey ... so I figure now I have stage 2 working .... Yes but No ... After I saved T-Stat 170/240 updates I fired up the furnace ... IT WENT STRAIGHT INTO STAGE 2 !!!!
I went back to the defaults.

I'm wondering if the problem could be caused by having the JUMPER between Rc and R up in the T-Stat?
The T-Stat manual says to remove the jumper for 2-transformer systems. Looks like there are 2 transformers in the furnace ... one bolted on the side and another taped and hanging from the main wire cluster. I'll have go take another looks to see exactly where the wires from the transformers connect up to.
Also there are 4 STATUS Lights on the furnace, amber/green/green/red ... the red one
flashes 8 times and then turns on for a few seconds and repeats the pattern. I noticed this today after removing the efficiency sticker that was covering the lower view window.

Oh BTW Furnace is a Rheem 95% Dual Stage Furnace Model RGRM-07EMAES &
T-Stat Honeywell Vision Pro 8000 touchscreen Model TH8320.

Any Suggestions? Thanks!

[amd]

Hey ... so I figure now I have stage 2 working .... Yes but No ... After I saved T-Stat 170/240 updates I fired up the furnace ... IT WENT STRAIGHT INTO STAGE 2 !!!!
I went back to the defaults.

Going straight to second stage is normal if the setpoint is well above room temp.

The second transformer is probably for a humidifier.

O is only required for heatpumps - if the installer connected it, he really has no idea what each wire does and shouldn't be working on hvac equipment.

[johnboy77]

You are right ... only 1 transformer for Heat & Cool. The other hanging one is for the
Humidifier. I tried new 170/240 settings again and only increased temp 1 degree ... furnace fired up full CFM (1200) and full flame. The red indicator is for CFMs ... 8 flashes equals 800 CFMs. I took some pictures ... Only 5 wired in T-Stat 2 are shadows ...

http://img59.imageshack.us/img59/4210/tstat.jpg

http://img32.imageshack.us/img32/4476/furnacewires.jpg

http://img524.imageshack.us/img524/5...ntrolboard.jpg

[amd]

The C terminal on the t-stat isn't connected to anything - you'll have to change batteries once a year.

As for staging, just run the furnace and see how it cycles; if it jumps to high when maintaining the setpoint in mild weather, there's a problem.

[johnboy77]

Thanks for the info on the C 24vac Common. I have the old transformer that was used for the old A/C that I counld used to power the T-Stat.

I think there is a problem. The way they setup the T-Stat is for 1H & 1C ... and that is
all it does only 1 stage heat ... no matter how high the temp is set. Changing the T-Stat to 2H-1C gets you STAGE 2 Heat ALL The TIME. Wiring looks Ok to me .... but my eyes are not the best!

I found an online manual for the T-Stat http://www.acdirect.com/xcart/images...stallation.pdf
(the funny thing is they don't show a 2H-1C wiring setup example on page 4 ... does it really work? The 170 setup function on page 7 supports 2H-1C?? Maybe I have a bad T-Stat?)

I also found a Rudd manual that had the exact same wiring info as the Rheem GRM Series Install Manual ... it's on Page 43 http://www.acdirect.com/xcart/images...ationGuide.pdf

I hate to think I have to live with a crippled system. I know most of the time only the Stage 1 Heating will be used ... but we get some real nasty cold weather in February.

So I really don't know what to do next ... call Rheem? Call Honeywell? Call Installer?
Call in a Different Heating & A/C Contractor?

[amd]

I think there is a problem. The way they setup the T-Stat is for 1H & 1C ... and that is
all it does only 1 stage heat ... no matter how high the temp is set. Changing the T-Stat to 2H-1C gets you STAGE 2 Heat ALL The TIME. Wiring looks Ok to me .... but my eyes are not the best!

Are you sure about that?

Did you let it cycle and maintain the setpoint for a while?

[Tiger93rsl]

You should just call the installer back out. And before they leave have them show you that it's working.

[johnboy77]

Hi AMD ... How would you go about testing Stage 2 heating with 2H/1C setup on the T-Stat?

Just update the T-Stat setup to handle 2H/1C ... and set the temp up a degree or two
... and let it run for several calls for heat? Are you thinking maybe it will reset itself and
start with stage1 heat?

Hi Tiger93rsl, I could call the installer back in ... but I suspect that he will just leave the T-Stat in 1H/1C setup and move the P7 jumper to 12 minutes and say that's the way it is! That is the BS he shoveled when he had only 4 wires to work with before replacing the T-Stat wires to 5 wires! Oh well I suppose I don't have much choice ... I'll have to get him in and prove that it switched to stage2 ... the only indicator I have is the FAN speed and looking at the flame....

Thanks!

[amd]

Just update the T-Stat setup to handle 2H/1C ... and set the temp up a degree or two
... and let it run for several calls for heat? Are you thinking maybe it will reset itself and
start with stage1 heat?

It will go into second stage even if the setpoint is one degree above the room temperature.

Just let it cycle a little bit and see what happens; there may not be a problem.

[mayguy]

Thanks for the info on the C 24vac Common. I have the old transformer that was used for the old A/C that I counld used to power the T-Stat.

DO NOT wire this transformer..

As said change the battery once a year.. I suggest to my customer change it in the fall when you change the clocks, and smoke alarm battery.

Your system is wired up correct.. Just set your temp that you want, and walk away.. The t-stat will cycle the stages as needed.

Make sure the Cycle per hour is set to 3.

[2hot2coolme]

Good grief....what a Joke!

[johnboy77]

Hi Guys,

I'll change the batteries every Fall and will NOT mess with the transformer. Thanks!

Made the following Changes on the T-Stat and I will let it be for the rest of the day.
I will let you know how it works out .... Thanks again for all your help!

I've set 0170 to "9"
System type
1 1 heat/1 cool conventional
2 1 heat/1 cool heat pump (no aux. heat)
3 Heat only (2-wire systems)
4 Heat only with fan
5 Hot water Series 20 system (power to open & close zone valves/normally open zone valves)
6 Cool only
7 2 heat/1 cool heat pump (with aux. heat)
8 2 heat/2 cool multistage conventional
9 2 heat/1 cool multistage conventional
10 1 heat/2 cool multistage conventional
11 2 heat/2 cool heat pump (no aux. heat)
12 3 heat/2 cool heat pump (with aux. heat)

0220 1st stage compressor cycle rate ... I Set it at '3'
3 Recommended for most compressors
[Other options: 1, 2, 4, 5 or 6 CPH]

0240 First stage heat .... I set it at '3'
cycle rate (CPH= cycles per hour)

5 Gas or oil furnaces of less than 90% efficiency
1 Steam or gravity systems
3 Hot water systems & furnaces of 90%+ efficiency
9 Electric furnaces
[Other options: 2, 4, 6, 7, 8, 10, 11, 12 CPH]

0250 Second stage heat cycle rate (CPH) ... I set it at '3'

5 Gas or oil furnaces of less than 90% efficiency
1 Steam or gravity systems
3 Hot water systems & furnaces of 90%+ efficiency
9 Electric furnaces
[Other options: 2, 4, 6, 7, 8, 10, 11, 12 CPH]

[amd]

Looks good.

If you want 2nd stage to cycle on and off less agressively, set option 250 to 2.