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

learn more… | top users | synonyms

2
votes
0answers
27 views

Air handler for an AC in the attic collect about 1 cm of water in it before it is high enough to drain… problem?

My air handler in my attic won't drain water(because the hole is 1cm above the pan) until the water reaches that hole. Why is this setup this way. From what I have read, NO water should be in the ...
2
votes
0answers
36 views

Should I get a single- or two-stage furnace for my three-floor brick home?

I just bought a house that has a furnace on its last legs. The house is 1941 masonry in Chicago with 3 floors: finished basement, first floor and a second floor that is a converted attic with vaulted ...
2
votes
0answers
352 views

How can I insulate and elevate an A/C line set on a flat rubber roof?

The Scenario An apartment building with a flat black rubber roof. The A/C condenser is on a platform on the roof with an air handler inside the unit. The line set runs across the roof for about 20 ...
2
votes
0answers
694 views

What are good Relative Humidity and Temperature settings on an MHRV and are the settings related?

I need to configure the threshold Relative Humidity and Temperature settings on an whole house MHRV system. The way the system works is that if the RH threshold is exceeded the system increases the ...
1
vote
0answers
17 views

Clean filters and dusty house

I have good airflow and a very dusty house and large dust balls. I have used all kinds of filters including the pleated. When filters are checked in 3-6 months they are as clean as the day they were ...
1
vote
0answers
45 views

AC capacitor testing with multimeter

When running through my check list to start the AC for the spring/summer I noticed the outdoor fan was not running, hence no cooling. I'm using a basic digital multimeter to test a capacitor with the ...
1
vote
0answers
57 views

Thermostat will not power on with C wire, but it has voltage

I recently purchased a Honeywell wifi thermostat and tried to hook it up as a replacement for an existing battery powered unit. I have a typical forced air HVAC setup with gas furnace (no heat pump), ...
1
vote
0answers
15 views

Comfortmaker Run Capacitor Location?

Where is the blower run capacitor likely to be physically located within a Comfortmaker central HVAC unit? Access is tight in the attic space. Thanks!
1
vote
0answers
24 views

Thermostat replacement in a double wide

We have a new double wide and I want to replace the thermostat with a new programmable one. We took off the old one and it has 3 red wires, 2 yellow, 1 white and 1 green. I get the 2 red indicate a ...
1
vote
0answers
33 views

time delay adjustment on Rheem elect furnace

Upon a call for heat the blower motor starts too soon resulting in cool to cold air coming out of the ceiling registers until heat strips start heating up.Wires coming from thermostat connect to ...
1
vote
0answers
54 views

HVAC - hot air flowing on both zones when only 1 zone should be on

I have 2-zone forced air heating, with separate thermostats for each zone. Normally, if the thermostat in zone 1 triggers the system to go on, the heat will only blow through the vents in zone 1. ...
1
vote
0answers
42 views

Mini Split condensate pump to condensate drain

I'm working out the details of my Mini split. I know by code I have to have it connected to a 3/4" condensate line going outside. The Mini Split's air handler is located on an inside room where I'm ...
1
vote
0answers
29 views

Temporary Remove Flex Duct

I am about to replace a load bearing wall in unfinished basement. There is flexible duct attached to plenum that I need to temporarily move out in order to put the beams in. Do i just need to cut ...
1
vote
0answers
23 views

Is there a “bending rigidity index” of some sort for semi-rigid aluminum ducts?

Some semi-rigid aluminum ducts bend easily and others do not. I want to purchase semi-rigid aluminum ducts online of a specific bending rigidity/stiffness that minimizes sagging but can be easily ...
1
vote
0answers
27 views

How to connect 4 fan coils with one wall control thermostat?

I have 4 fan coils (Sabiana sk-22)and I want to connect them with one wall control thermostat. How can I do?
1
vote
0answers
28 views

Thermostat and thermostat system for small business with several units and tenants

Am the facilities guy in a small church and pre-school. There are 8 heat pump units through out the church/schoool. Each has a stand-alone thermostat and they are all different. I would like to get ...
1
vote
0answers
41 views

Should I install a doorway fan or dehumidifier?

I have central air in a rancher (one floor), and the living room is on one end of the house. That room is on a slab, and has always been noticeably hotter in the summer and colder in the winter than ...
1
vote
0answers
30 views

Help AC question

We purchased a home last year, at one time it was zoned with separate AC units upstairs and down. Well a past owner took out the upstairs unit but left the blower in the attic, there is duct work ...
1
vote
0answers
553 views

A/C still blows when unit is off.

Our A/C is turned off but we still get cold air coming out of the vent diffusers. This is from our downstairs unit. Is that a problem?
1
vote
0answers
120 views

Can I remove HVAC pipes after exposing the ceiling?

I recently removed the drywall ceiling from my basement and have two related questions about removing the HVAC ducts/pipes. Pictures attached here: http://imgur.com/a/qep4w 1. Is it OK to remove the ...
1
vote
0answers
76 views

Does polarity matter when wiring a humidifier solenoid?

The 56 was receiving 24vac whenever the furnace was on via a red wire and a white wire. 24vac was supplied to the solenoid when humidity was called for via a pair of junction terminals. The 4655 is a ...
1
vote
0answers
74 views

Should I look into getting an active or passive whole-house humidifier?

My wife and I moved into our place a few months ago. Now that is is winter, the humidity levels dropped down to 20% throughout the house. We want to install a whole-house humidifier to raise it up ...
1
vote
0answers
103 views

How to clean carbon build-up on Honeywell whole house air purifier made of aluminum?

Bought a house recently that has a Honeywell F300 whole electric house air purifier/cleaner. The cell's aluminum fins have a black baked-on dust that I expect is preventing the unit from working as ...
1
vote
0answers
56 views

Testing the exhaust of a natural gas furnace?

I recently had maintenance performed on my natural gas forced-air furnace. During this maintenance, the technician went outside and used an electronic handheld device with a wire-attached probe to ...
1
vote
0answers
151 views

Can ultrasonic humidifiers be used in a bypass setup for a whole house humidifier?

My home is about 3000sqft, with lots of high ceilings. I'm having trouble keeping the relative humidity up in the winter. When it gets down to 10F outside, the RH drops down as low as 25%. This is ...
1
vote
0answers
35 views

Why is my hydro kinetics system blowing out cold air?

I have a hydro kinetics system that is blowing out cool air when set to heat. Thermostat was replaced when I bought the house a year ago so I don't think that's the issue. Toggle switch is set to ...
1
vote
0answers
38 views

How can I reduce the noise from an HE boiler vent?

I have a HE boiler that is direct vented out the side of my house on the neighbors side, they find the 'roar' of the exhaust to be very annoying. Have anyone tried troubleshooting these to ...
1
vote
0answers
209 views

How can I install a furnace register in a kitchen-cabinet toe kick?

I'm planning to install new kitchen cabinets. I'll be covering up the kitchen's existing sidewall diffuser with new cabinets, so I'd like to relocate it to a new register in the toe kick of the sink ...
1
vote
0answers
1k views

How can I tell if my bathroom ceiling vent is working properly?

Seems to take the vent forever to clear shower vapor from room. I purchased a vent that had a good rating. It is vented to the outside. How do I know if it is working properly and actually venting to ...
1
vote
0answers
2k views

Reducing air conditioner compressor vibration noise

I have a two year old Carrier air conditioner with an outdoor condenser. The condenser sits on a plastic pad on the side of my house, and I have two--one for downstairs and one for upstairs. ...
1
vote
0answers
89 views

How do I troubleshoot my central A/C?

It's 79 outside right now. It's been running for hours and it's remaining 79 inside. I'm in a brand new 2 story home in Monroe, OH. It has rained a lot recently but I just feel like it should be ...
1
vote
0answers
99 views

Why doesn't my A/C get power when using the alternate C-wire thermostat hook-up method?

I changed my old Honeywell thermostat for a new Honeywell WiFi thermostat. I installed it just as the directions stated. I used the alternate C-wire method as the old unit did not have one. ...
1
vote
0answers
3k views

How do I size a wall sleeve for a through-the-wall air conditioner?

We are shopping for a through-the-wall air conditioner. We do not currently have a hole in the wall with a sleeve in it. We are trying to figure out what sleeve to buy. The air conditioner we like ...
1
vote
0answers
3k views

What's causing my draft inducer to stay on?

I have a new, 3-year old, high-efficiency, gas furnace in my home. I recently realized that my draft inducer, which normally kicks on before the burners and before the main blower, is not stopping. ...
1
vote
0answers
1k views

How can I properly drain heatpump condensate?

I have a heat pump in the attic That drains to the ground outside two floors below. I naively added a hose fitting so I could redirect the water where I wanted it, slightly up hill. This created a ...
0
votes
0answers
14 views

Should I have a ceiling fan whose blades extend to the register?

Currently, the ceiling fan fixture and the 10x6 register are spaced by about 32" (~2 stud lengths). The room is about 350 sqft. Should we purchase a 70" ceiling fan so the blades extend out past the ...
0
votes
0answers
12 views

Cleaning of TempStar air conditioning parts

It's been 6 years since I bought the Tempstar 4 ton a/c. So far, it is running okay. But when the need arises, I want to be BOLO and do the repairs myself. So, how do I clean a TempStar a/c ...
0
votes
0answers
20 views

Both A/C air handler and outside unit won't turn on

I went to turn on my A/C for the first time this year, and nothing happened. I checked power to both the air handler and outside unit...both at getting 220v going into the boards on each. I then ...
0
votes
0answers
15 views

Need to find control valve for damper

There is no control valve attached to this damper: so I can't turn it to open/close the duct. It's currently closed :-(. It's smooth so I haven't found anything that can even grasp onto it tightly ...
0
votes
0answers
32 views

AC is freezing after one day of full use

I had my AC unit serviced two months ago. The unit is about three years old. This week is the first week we have had it turned on all day. Last Sunday I noticed that the AC was on, but no air was ...
0
votes
0answers
64 views

AC Unit does not receive 24 volts on outside unit

My outside unit does not turn on itself, but it does work. I just did a quick repair just thinking it was the capacitor and it was only 15 dollars for a new one so I changed that out and still had the ...
0
votes
0answers
41 views

Removing stuck “through the wall” air conditioners

I have two through wall air conditioner units that cannot be removed. These were installed within sleeves in the 1970s and have been sitting there ever since. One budges a little and the other, not at ...
0
votes
0answers
51 views

Yellow wire connected to C terminal, blue wire connected to Y terminal at furnace

I'm trying to install a new smart thermostat the requires a C wire. My old thermostat operated on batteries. The pre-existing wiring system of the old thermostat looked normal (ie. red wire to Rc, ...
0
votes
0answers
14 views

Why does my hvac minisplit freeze up?

What would cause a mini split to freeze up? The Freon level is correct and the air flow is good. This is a multi head system (2) one is working properly the other is freezing up.
0
votes
0answers
14 views

Can I increase the “constant on” speed of my air handler?

I have an American Standard TWE049E13CB air handler with a variable speed blower. The manual has a chart to adjust the dip switches for fan speeds for cooling, heating, fan off delay, and auxilary ...
0
votes
0answers
77 views

How do I connect a honeywell wifi thermostat with no C wire at the furnace?

I purchased a Trane XV90 furnace in 2001 & I'm upgrading the thermostat to a Wi-Fi model. This thermostat needs a wire labeled C from the furnace & of the 4 wires coming from the furnace none ...
0
votes
0answers
26 views

Improving air flow using supply and return exhaust fan with split type air condition

I have slight issue with uneven temperatures between two rooms. Say we have two rooms, Room 1 (cold room with AC) and Room 2( without AC, hotter room). Room 2 is ventilated by Room 1 AC by opening ...
0
votes
0answers
6 views

furnace blower not working off of thermastat

I replaced mother board of furnace and the fan blower turns on but my wires from thermastat are not plugged in.black wire on Hi red on low white on com if unplug hi it does not turn on
0
votes
0answers
12 views

Safe to install a 3 Ton HVAC with 8" ducting

I currently have a pretty old 2.5 ton HVAC installed and it broke down recently so I need to replace it. I've had a couple companies come out and give me bids and they both insist that I need to ...
0
votes
0answers
33 views

Theremostat indicates low battery even with new cells

I have a 3 story home with 3 different thermostats, one on each level. The first floor one says "lo batt", so I changed the batteries. That thermostat still reads "lo batt" and my system will not turn ...