Questions tagged [hvac]

(Heating, Ventilating, and Air Conditioning) For questions about installing, repairing, and troubleshooting HVAC systems.

404 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
1
vote
0answers
42 views

thermostat does not accept C wire connected to AC unit

I have three identical thermostats, model Radio Thermostat CT101. Two of them have C wires connected to the burner and work fine. The third one controls a heating zone and also central AC. It has R ...
1
vote
0answers
43 views

CAR duct in same bay as electrical wire

I'm going to install a cold air return (CAR) duct through an interior wall that has some electrical running through it. The CAR duct will run vertically, but near the bottom third of the bay there is ...
1
vote
0answers
20 views

Can I place the MUA vent directly beneath the range?

In California, I'd like to upgrade my range hood and may require make up air. I've seen these installed in the toe kicks of kitchen cabinets. Would it be acceptable to install registers directly ...
1
vote
0answers
33 views

Heating zone only partially working for gas boiler

I did all of these things: Checked the pressure and temperature, which looked OK Attempted to "purge" the area. The zone (let's call it Zone 2), was purged by opening the valve on the return. I had ...
1
vote
0answers
82 views

No 24VAC between R and C on Rudd R801 Control Board

I’m replacing a older programmable thermostat with Ecobee 4 which is to control a Ruud R801 HVAC unit installed last year. I have access at the thermostat to a wire (orange) that goes to the C ...
1
vote
1answer
62 views

burners out of sequence with blower motor

I have a Bryant furnace plus 90 model #398AAW036060D. I just changed the blower motor. In the last five years I've changed the main board, inducer board, pressure switch, and cleaned the igniter the ...
1
vote
1answer
64 views

Heat pump always turns on with fan!

If I turn my fan on on my thermostats the heat pump turns on with heat or cool setting There is a jumper wired from green to w1(the heat pump) If I move the jumper to r (24v) and g and turn on the ...
1
vote
0answers
63 views

Honeywell Thermostat to Nest E Dehumidification

I am trying to replace my Honeywell Prestige IAQ thermostats. I noticed that my downstairs thermostat has a dehumidification option (upstairs shows no such option). I checked the wiring at the ...
1
vote
0answers
49 views

Dual energy controller 2AC02700701 runs heat pump with low fan only

I am running a central heat system that uses a heat pump as stage 1 and a gas furnace as stage 2. The thermostat is not directly connected to the furnace and heat pump motor, instead to goes through a ...
1
vote
0answers
630 views

Where should I connect my C wire on Goodman GMP075-3 Rev.B

I am trying to install an ecobee4 to replace a digital battery powered thermostat. I removed the existing thermostat and found that there was a spare blue wire that was wrapped around the others that ...
1
vote
0answers
698 views

How to wire a Taco zone valve controller with ecobee

I'm having an issue with wiring my Weil McLain gas boiler. It was wired up fine and working for a single zone. I added (2) 4 wire zone valves in. So I now have 2 zones, a Taco zone valve controller(...
1
vote
0answers
43 views

unique ? about venting tankless water header

I am installing a tankless water heater at the house. My question is unique because I can not find a reference anywhere in the code and the installation manual about where to place my exhaust vent. I ...
1
vote
1answer
792 views

Connecting Wood/Electric Furnace to Smart Thermostat

UPDATE: I spoke with an ecobee tech and they pointed me to an alternative solution. If I get an adapter called a "Fast-Stat Common Maker", all I need to do is figure out where to connect the C-Wire ...
1
vote
0answers
24 views

Upgrade Rooftop HVAC

I am planning a rooftop HVAC upgrade. My current HVAC frame (leg) has cracked one of the 2 x 6 roof rafters that I have repaired with wood glue and anchor screws, so it is good now, but it served as a ...
1
vote
0answers
80 views

How do I calculate fan size for a single room exhaust system to reach a desired cfm when restricted to specific duct size/route?

I am wanting to exhaust a sealed room (except for air intake and exhaust). The room is 512 ft3, and due to positioning, orientation, and existing construction, I am restricted to using 6" flexible ...
1
vote
2answers
73 views

HVAC Supply and Return Re-routing

We are planning a rehab of our first floor (2-story home). The furnace and air handlers are in the basement for the whole house. The supply and return for the 2nd floor run STRAIGHT up to the second ...
1
vote
0answers
305 views

Trane xv90 blower won't come on regardless of what the thermostat is set at

I have a trane xv90 and the blower won't come on. I'm getting about 20 green flashing lights and then 1 red which kinda overlaps the 21st green. What does it mean? I had turned on my trane air ...
1
vote
1answer
182 views

Which terminal should I connect it to for a “C” wire on an american standard AM4A0A30

I'm trying to connect a 3rd gen Nest thermostat. I have a 2 zoned heat and 1 zone AC. The zone with this thermostat has a boiler wired Rw, W1 and HVAC wired Rc, G, Y1. It's summer so I'm only using ...
1
vote
0answers
56 views

What heating mechanism do I have and how do I turn it off?

This is a bit embarrassing but I'm unable to figure out how my house is actually heated. I have some vents in the wall (just above the baseboard), which blow out hot air and are controlled by one ...
1
vote
0answers
208 views

Changing AC Fan Motor/Capacitor with No Luck

Issues with a central AC unit: Turned it on and heard a buzzing sound, but the fan didn't start. Started by looking at the dual capacitor. We happen to have two identical units, so I tried the ...
1
vote
0answers
4k views

Carrier Infinity System says “System Malfunction”

On this, the day temperatures reached 95, my AC stopped working. Here are the symptoms: The thermostat says "Infinity System - System Malfunction Call Technician". The condenser outside is spinning, ...
1
vote
2answers
386 views

Problem with condensation on HVAC ducts inside house

I'm having a pretty serious problem. There is an old sheet metal HVAC duct in my home that is getting condensation that is dripping onto the ceiling of a pantry. This duct is completely internal to ...
1
vote
0answers
103 views

Correct wiring for Nest thermostat with dual HVAC system

Trying to wire up this new-fangled Nest Thermostat E (the cheapy edition) to my home HVAC system, but unsure of what to do. At the thermostat, I have G, W, Y, R, AND Rc wires, but the R and Rc wires ...
1
vote
0answers
2k views

Furnace Mainboard wiring with AC unit

I went to install a Nest on my upstairs HVAC unit. After installing the Nest I thought it was functioning properly. The next afternoon I came back to the house It was still hot, so looking into this ...
1
vote
1answer
103 views

Is there a way to change the location of HVAC air filter location?

We bought the house recently. Heating system was recently installed by the previous home owner. I cannot believe they did not think of this but the place for filter is inside the furnace. The problem ...
1
vote
1answer
41 views

HVAC Adding a Common

Got a new Honeywell WiFi thermostat and need to add a common. Currently the 3 common wires per the diagram (BL, BK, GY) are wired to one side of the AC Unit. Is there an issue if I piggy back a ...
1
vote
0answers
1k views

How to understand the red and green blinking lights in Trane gas furnace?

My 8 year old Trane Model tuh2d120a9v5va furnace is not giving out heat, but the blower is on. The service people are all busy due to the recent storms. I imagine the ignition is not working. ...
1
vote
1answer
137 views

Which humidistat terminals should I use for my humidifier?

My Carrier furnace does not have a humidifier connection on the control panel. I have two wires from the humidistat. Do I use W-C or R-C connections for a normal operation?
1
vote
0answers
1k views

Furnace Condensate freezing on siding

I am helping a client with an issue related to the condensate line on their furnace. It is a high efficiently LP furnace installed in an attic with a condensate line that drains to the exterior. The ...
1
vote
0answers
30 views

Switch from 5“ HVAC Air Filter to 4” Air Filter?

Hi: I have 2 HVAC systems that use 20" x 24" x 5" air filters that are quite expensive to replace @ $60 each every 9 months. Would switching to 4" filters be ok assuming I change them slightly more ...
1
vote
0answers
45 views

furnace wont kick in

My furnace seems to work intermittently. overnight its seems to stop... i have checked the thermostat and it shows says it is heating. fan is on auto, but nothing coming out. when i turn heat to off, ...
1
vote
0answers
2k views

Running Airwave/Fan schedule with Nest (With Fresh air intake HVAC)

I am trying to make sure I am understanding the research/studies behind using just the fan to help reduce energy to cool/heat home. Nest has the option to set a schedule to run the fan in home to ...
1
vote
1answer
1k views

Air handler turns on even when set temp is reached

My HVAC is a heat pump system, the air handler inside is a Goodman aspf183016ea. The whole system/house is about 3 years old, and is all electric. I recently moved into the home and noticed that the ...
1
vote
0answers
3k views

Nest thermostat - electrical buzzing/humming noise

I have recently installed two nest thermostats (the black gen 3, and white model E). The system is gas radiator heat wired to the model E via the usual Rh and W wires, and Rh, Rc, Y, G, W wired to the ...
1
vote
2answers
429 views

Furnace Blower fan doesn't start

I have a keeprite high efficiency furnace that Was a part of my new house. It's 2016. The Honeywell thermostat is set at 23 deg C. This is what happens when the temperature is below the cut-off I ...
1
vote
3answers
742 views

Furnace turns on and lights without Inducer Motor Coming On

Without my brand new inducer motor coming on at all ever when power is turned on my gas furnace starts,igniter starts andlights pilot and then burners light and then big flame blowback like its ...
1
vote
1answer
280 views

C Wire placement in HVAC?

I'm installing a new thermostat and the previous one did not have a C wire connected. Tracing in back to the HVAC, I can't see a C output connection? Based on the wiring diagram (and reading other ...
1
vote
1answer
556 views

Old AC and Gas Boiler wiring for new thermostat

I need help connecting a new 'C' wire for a Honeywell RTH6500WF thermostat. As you can see the heating is an old boilder with a simple pump to circulate the hot water to the baseboard radiators. The ...
1
vote
1answer
282 views

How should I jumper the transformer to use a thermostat with my heat pump?

I am hooking up an aftermarket blower motor on my Trane XL 1400 AC/heat pump. I have a black, blue, red & white wires coming out of the new motor. I am bypassing the circuit board so I am ...
1
vote
0answers
51 views

Heat pump shut down after 15-20 secs in cool mode

I have a York Stellar 2000 series Heat Pump model E1CS add-on system to a gas furnace. The heat pump had been working fine for a great many years. It now has problem in the cooling mode. When the ...
1
vote
2answers
104 views

Air Conditioning and blower problems

Ok, the blower unit will run on heat and fan on. However when I switch to auto and cool the blower unit doesn't run. When I have the blower in the "on" position it will run until I switch the ...
1
vote
0answers
1k views

Putting a window air conditioner into an awning window

I bought a window air conditioner thinking that I could alter my awning window to accommodate it. I have since discovered that I can't remove the part of the window that swings out or alter it so that ...
1
vote
1answer
886 views

Can I run a C wire from Fan Relay

We've just moved into a new home with an heat only, oil, forced hot air furnace. The current thermostats are very old and we'd like to update them to something like a nest. The furnace is currently ...
1
vote
0answers
11k views

'Wait' indicated on my Honeywell RTH7400 thermostat after 1 week vacation

New Homeowner (December) and I need help troubleshooting. Everything was peachy keen until I returned from a week vacation. A/C will not cool, but fan will turn on if I take it off of auto. "Wait" is ...
1
vote
0answers
594 views

Changing Furnace to Direct-Vent, can i get rid of these pipes?

My 96% furnace uses a PVC pipe to exhaust the combustion gases to the outside. The intake is currently taken in through a inlet similar to the exhaust on the left side of the furnace. It does not ...
1
vote
0answers
200 views

Can I usefully control an electric baseboard heater in 1 room with the same thermostat as my central heat?

My house has a gas furnace and heat pump (and AC). Unfortunately, one bedroom does not have air ducts hooked up. Is there a way I could install a baseboard heater in that bedroom and have it ...
1
vote
0answers
777 views

Replaced HVAC Transformer, still have no output voltage

My HVAC stopped working, no matter what state the thermostat is in there is no fan, no compressor, no heat, etc. Using a multimeter, I found that the output voltage on the transformer was 0V. ...
1
vote
0answers
52 views

Studio HVAC Solution

I have an interesting situation where I am in a studio that is approximately 300 sq. ft., and should require ~9,000 BTU/h (3/4 ton) heating/cooling capacity. There are three rooms--A bedroom (~11x8), ...
1
vote
1answer
1k views

C wire and smart thermostat

I'd like to install an ecobee3 thermostat, but I'm not entirely sure about my wiring. The current thermostat seems to only have a W and RC wire coming into it. There is also what appears to be a blue ...
1
vote
1answer
733 views

Wiring a C (common) wire to a Triangle Tube Prestige Excellence 110?

Wiring noob here. Can someone give me step-by-step instructions for where and how I should attach a C (common) wire to a Triangle Tube Prestige Excellence 110 boiler for a ecobee3 thermostat? I think ...

1 2
3
4 5
9