Original message
| Halksw
 |  "Verify correct operation of 2 stage furnace"
, posted Sun 6 Jan 22:05  
I have an Amana amv9070 2 stage variable speed furnace which is controlled by a Honeywell RTH7500D thermostat...this furnace was installed last winter.
How do I verify if the furnace is actually working on both stages...I do notice the fan is changing speeds but I'm not sure how to verify that both heating stages are working correctly.
Also, it takes about 90 minuted to raise the temperature 3 degrees in the morning...not sure this is normal.
Thanks
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Replies:
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| Halksw
| "Re(1):Verify correct operation of 2 stage fur" , posted Sun 6 Jan 22:24
I've been watching th flame as the fan speed changes but I don't see a difference...maybe it's only running on stage 1.
Not sure if the thermostat is correct for the furnace however it's set for multi stage heating with wires connected at W and W2.
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| smythers1968
| "Re(1):Verify correct operation of 2 stage fur" , posted Sun 6 Jan 22:13
THe simple way is to watch the burners in the furnace. When the fan speed changes so should the gas pressure. The flames will also get larger.
I might advise you to call the installer and have temp rise reshecked. 3 degree in 90 min seems very long.
Temp rise is supply air - return air. You want around a 55 degree difference.
Life lesson #12 Know when not to do it yourself.
WOW That Can Hurt!!
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| | smythers1968
| "Re(2):Verify correct operation of 2 stage fur" , posted Sun 6 Jan 22:30
I'm not very familure with amana.
I would advise you to call the installer. There should be dip switches and they may not be set correctly.
Life lesson #12 Know when not to do it yourself.
WOW That Can Hurt!!
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| | TKG26
| "Re(3):Verify correct operation of 2 stage fur" , posted Mon 7 Jan 20:01
Yes call back the installers. Is it a 2stage or 1stage stat? That will make a difference with wiring and dipswitches. The ammana with a 1stage stat will determine its own staging based on cycle history similar to how carrier does it. If the dips are wrong you may not get proper staging
SIGNATURE "Always have a licensed HVAC technician perform repairs on your equipments. HVAC is not a do-it-your-self home project."
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| | dwcaveney
| "Re(3):Verify correct operation of 2 stage fur" , posted Mon 7 Jan 16:50:
Do you have the 2 stage t-stat both w1 and w2 hooked up? How big is your house? The Amana is a Goodman. The IC board is different. Does it have a White Rodgers gas valve? My 2 stage Goodman will work with a 1 stage T-stat. Your Amana needs a W1 and W2 connection. My Goodman 2 stage operates at .3 amp low .43 amp high same circuit. I believe your valve requires 2nd circuit for high stage (W2). Check function 170 T-stat program options, select the number for 2 stage heat. I believe you have 2 stage heat with [multi speed blower.(the IC board would do that)]
[this message was edited by dwcaveney on Mon 7 Jan 17:19] |
| | Halksw
| "Re(4):Verify correct operation of 2 stage fur" , posted Mon 7 Jan 23:11
Yes, both W and W2 terminals have wires connected to the corresponding furnace terminls...the option for 2 stage heating and 1 stage cooling is selected. House is 1800 sq ft.
Thanks
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| | dwcaveney
| "Re(5):Verify correct operation of 2 stage fur" , posted Tue 8 Jan 02:46:
Seems sized right. Do you have a drip leg on gas line? Can you see it kick into high like Smythers said? 90 minutes is hard to believe. I think your model burns 66% x 70k=47K+-on low. I'm not familiar with DIP switches on the variable. Check your manual, if possible set it shortest delay to 2nd stage. If that don't work, you might have a bad gas valve.(I did read that that model will work right without a W2, the board will do it but not as exacting they say)T-stat set-up could be a little complicated. On the Goodmans the board doesn't rely on the T-stat to 2nd stage, it just uses the termistor and the DIP settings. Set the DIPS right and try just the W. Set the T-stat option to single, single.
Good Luck
[this message was edited by dwcaveney on Tue 8 Jan 03:24] |
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