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

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2
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0answers
335 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
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0answers
105 views

Should I install the jumper on my new limit control?

I needed to replace fan and limit control (White-Rodgers, model 5D51-35), because the fan switch was broken (fan would constantly run) and heat would not stay on. I took a picture of the control, ...
2
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0answers
674 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
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0answers
36 views

How to power Honeywell wifi thermostat with external transformer

I want to install A Honeywell RTH 6580 WF thermostat in my garage for heat only . My heater is a simple LP gas, hanging unit heater; heat only and my thermostat has two wires labeled W and R . I ...
1
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0answers
24 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 ...
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0answers
48 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. ...
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0answers
29 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 ...
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0answers
27 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 ...
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25 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?
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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
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0answers
20 views

Single Stage or 2 stage furnace

Just bought a house that has a furnace on last legs. House is 1941 masonry (Chicago). 3 floors: finished basement, first floor, 2nd floor (converted attic with vaulted ceilings and way too hot). Total ...
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0answers
37 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 ...
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0answers
29 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 ...
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253 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?
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0answers
97 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 ...
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0answers
70 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 ...
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0answers
66 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 ...
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0answers
88 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 ...
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0answers
55 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 ...
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0answers
128 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 ...
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0answers
34 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 ...
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0answers
36 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 ...
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0answers
198 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 ...
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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 ...
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0answers
1k 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. ...
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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 ...
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0answers
98 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. ...
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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 ...
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0answers
2k 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. ...
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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
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0answers
11 views

Lenox home AC unit doesn't turn on at all, I need help

If you try to turn the out side unit from out it will turn on , but from inside it doesn't do anything. I check the fuse in the inside unit is good, check the overflow it looks good. I just can't ...
0
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0answers
28 views

calculating the size for an a/c compressor

I have been looking around and can't seem to find this anywhere. I am trying to figure out how to size an a/c compressor to an a/c system. Unfortunately I have not sized out the system, so there isn't ...
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0answers
49 views

Is there any problem with installing underfloor heating and wood flooring?

I have planned to renovate my home.I want to install underfloor heating system of Airdex for my home.I am planning to go with wooden flooring as well so will I face any kind of problems in future ...
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0answers
23 views

Liquid line freeze up

Why would the liquid line on residential air conditioner freeze up during winter months, even though compressor isn't running? Have shut breaker off to assure outdoor unit isn't coming on.
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0answers
35 views

How to remove ice buildup from window air conditioner

My fan froze on my AC unit in my bedroom window. I was able to move the inside one when it froze, but this one is on the outside. Should I spray hot water on it to get it to move? I was going to use a ...
0
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0answers
56 views

Why would my heat pump AUX be kicking on with 1 degree change?

So this is weird, and I literally just noticed it today. I have a Honeywell 5-1-1 Day Programmable Thermostat – RTH6450D. That works fine, I have a heat pump system (Carrier 2-ton). Today for some ...
0
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0answers
35 views

Can a furnace safety limit switch with manual reset be changed out with an auto reset switch?

I have a Ruud natural gas furnace from 1987. Overall it works well. I've had my home warranty service send out an HVAC tech a couple times for the high limit switch needing to be reset. It's a manual ...
0
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0answers
24 views

Where can I find a user manual for the Honeywell 32207455 thermostat?

How can I obtain a manual for the subject thermostat? There seems to be no manual on the internet. We are trying to adjust the system and run into several questions.
0
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0answers
31 views

goodman furnance just keeps runing no heat why

recently i have had problem with my goodman furnance all it seems to do is blow air on very low speed and does not seem to stop furnance just keeps running i replaced limit switch work fine but after ...
0
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0answers
48 views

Could my New Hot Water Tank be improving my Furnace

I've gone thru 2 blower motors in my furnace in 3 yrs. Techs don't know why. I purchased a New Water Tank recently and it seems strange but my furnace is working better. Usually I could hear noises ...
0
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0answers
22 views

coleman furnace model dgaa furnace heats up and shuts down berfore blower starts and flashes code 4

york DGAA will work fine until it gets close to hot enough for the blower to turn on. I said close to turning on because I think it should get hotter but I'm not sure just guessing. The upper limit ...
0
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0answers
187 views

No C wire terminal on my electric plenum but there is on my furnace. How do I solve?

I had a brand new furnace installed recently but also now picked up a wifi thermostat. The problem I now encountered while installing the thermostat is that my system also has an electric plenum as ...
0
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0answers
17 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 ...
0
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0answers
85 views

What makes a furnace pilot valve whistle?

I have a furnace that started whistling, recently. I have read that gas pressure changes can cause this. Others have remarked how seasonal gas changes can lead to a properly-adjusted furnace to ...
0
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0answers
28 views

Pellet Stove Ventilation

I have an Englander PDVC pellet stove that came with my house when I bought it in the spring. Never used it. Currently its vented through the wall and comes straight through the exterior of the ...
0
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0answers
58 views

Smaller Footprint of new Furnace Base Cabinet

Replaced downdraft furnace in 1950's ranch house built on slab. Base cabinet of new furnace has a smaller footprint than the original resulting in a 4in. gap between the edge of the cabinet and the ...
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0answers
31 views

Can my A/C unit knock out my whole trailer or is it coming from the main box outside causing the problem?

I'm confused. Do you know if my air conditioner unit would blow out the main power in my whole trailer if the box inside my house isn't tripping? It keeps making a very loud popping noise under my ...
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0answers
37 views

Ac running but my blower will not

My ac unit stopped feed cold air from the unit outside. The main fan on top is spinning fine and my lines are freezing but the blower in the unit is just barely turning. Can someone tell me what would ...
0
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0answers
54 views

Older home with no AC plenum…replace our entire AC system as suggested?

We have an older home that has a large living-area/fireplace room; the AC unit sits over it in the attic. Earlier this year, in that room, we noticed a crack beginning to form in the ceiling sheet ...
0
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0answers
29 views

Goodman A/C unit sparks at high pressure line on furnace. Blows breaker

Got a 10 year old A/C unit and notice breaker blown. Flipped breaker and noticed a spark where the high side line goes into the plenum of the furnace and the breaker blew again. A/C repairman checked ...