Carrier Furnace

[bill18163]

I had a Weathermaker Infinity installed in Nov. of 2002(58MVP). I change the filter myself at regular intervals. Other than changing the filter I have had no checkups or service since it was installed. Now for my question. The furnace seems to go on high output a lot. I keep the fan running constantly which makes for an even heat in the house at all times but of course when it goes on high output you can hear the differance. The only thing I am going on here is a guess on my part that this is happening judging from the furnace being in operation for the last three years. In the past it would only go on high when the weather was below 20 degrees or lower outside. The temps around here have been in the forty's for days and the furnace goes on high output more than I think it should. Does this furnace need a lot of fine tuning? Does it need to be looked at before each heating season?

[Advanced Response]

I recommend the furnace should be serviced every fall and the a/c every spring by a competant hvac technician/company..

As far as the cycling goes to high.. What type of thermostat are you using? Are you using agressive temp setbacks?

A 2-stage unit should be controled by a two stage thermostat!! A great thermostat to compliment your furnace would be a Carrier/Bryant Thermidastat.. This type of thermostat requires 9 available t-stat wires to control heat stage 1 and 2 independently, single stage a/c, dehumidifier control in summer(slows blower in a/c mode when humidity is above set-point), outdoor air temp probe, and fan control... If you have a 2 stage a/c unit you will need 10 t-stat wires.. Also if you want to control a humidifier you will need 10 t-stat wires.. If you have both 2stage a/c and humidifier you will need 11 wires..
This is the best contol for your unit!! Period..

Good luck
J

[bill18163]

I keep the thermostat at 70-72 during the day and turn it down to 67 at night. I have the Carrier Thermidastat. It was installed by the Carrier dealer.

[Advanced Response]

Do you know if they hooked the thermidastat up as a single stage or a two stage operation.. You would not believe the amount of two stage t-stats I see that are not even hooked up correctly to operate as a two stage t-stat.. There should be a separate wire hooked to W1 and another wire hooked to w2 at the furnace and t-stat.. You might want to have a tech checked to make sure the t-stat is hooked up properly when you have them do a furnace check-up..

Many times the thermidastats are not wired properly because the contractor didn't pull a new wire and the old t-stat wire did not have enough wire conductors..

Good luck
J

[bill18163]

"Advanced Response"
There is no wire hooked up to O/W2 in the Thermidistat(which should connect to W2 in the furnace). Have wires in the Thermidistat at points: W/W1--Y/Y2--G--R--DHUM--C--S1--S2. I am using wiring diagram for "Variable-Speed 2-Stage Condensing Furnace-With DE Connection-With 1-Speed Air Conditioner" which is correct for the equipment I have. Did check for the heck of it and there is no wire on W2 in the furnace. The wire harness to the Thermidistat has eight wires in it. If I have to hook up a wire from O/W2 to W2 I would have to pull in a single wire to do it. Did the installer use the wrong harness to begin with? Also,how is the furnace going to stage 2 if there is no wire between O/W2 and W2?

[Advanced Response]

The way your thermidastat is hooked up is not taking full advantage of the control.. You need another t-stat wire pulled and the thermidastat wired correctly for 2stage operation..

Right now your 2nd stage is being controled by the furnace control board which will run 2nd stage according to an algorithm.. Which also means that 2nd stage will run more often than actually needed and also with setbacks it may confuse the algorithm alittle..

I would recommend that you have another t-stat wire pulled that will enable you to have the thermidastat control the furnace to the peak of its abilities..

Contact a qualified hvac contractor for this is not a diy project..

Good luck
J

p.s. I would have the contractor pull another t-stat wire bundle that would allow you to have a few extra wires incase you want to add 2/stage a/c or a humidifier or any other upgrades in the future...

[Edited by Advanced Response on 02-04-2006 at 12:42 PM]

[bill18163]

"Advanced Response"
Thank you for your input. It prompted me to check things out. I was just reading the manual for the Thermidistat and found that by setting DIP sw #4 in the on position you can test various outputs. When in the heat mode during the test I got 4 min of low heat and I should have had 2 min of low heat then 2 min of high heat. I'll find a new harness myself with enough wires in it and install it myself. I have no problem with the wiring. Before I retired I was a locomotive inspector for the General Electric Co. in Erie Pa. We build locomotives for the railroads in this country as well as all over the world. Was responsible for all the wiring on the locomotive plus all the assembly,welding,pipe fitting and other related work. Again, thank you for your time. It's a pleasure to talk to someone like yourself that knows what they are talking about.

[kruzer2001]

The carrier thermidistat is not a true 2 stage stat. the board configuration will call for hi heat according to the algorithm. the o/w2 will only work when the dual fuel mode is selected

[jrbenny]

Kruzer:

Here's some reading for you.

http://www.xpedio.carrier.com/idc/gr...tstat-23si.pdf

It's a two stage stat. W2 is an active output in gas heat applications.


EDIT: Here's the wiring diagram, too.


[Edited by jrbenny on 02-04-2006 at 06:35 PM]