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

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3
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2answers
1k views

What kind of wall switch is needed for a natural gas fireplace to ignite consistently?

When we moved in, our natural gas fireplace worked well: Flick the switch & it would ignite. Years later, it started acting erratically: Sometimes, the switch worked, other times, no luck. We'd ...
1
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4answers
776 views

How can I calculate the power consumption of an A/C unit?

I have an AC unit with the following specs: Cooling Capacity: 1260 kcal/h, 1.47kW, 5000 Btu/h Fan Motor Power: 0.034 kW Current: 0.155 A My question is how much power does this unit actually ...
0
votes
1answer
63 views

Does HVAC lineset need to be grounded?

My HVAC contractor says the installation of the line set between the air handler and the condenser outside is complete but he has not grounded the lines. Do HVAC copper pipes need to be grounded?
2
votes
1answer
78 views

Is my Heat pump and gas furnace installation incorrect?

I moved into a house about 2.5 years ago, and the previous owners had a heat pump installed, together with a gas furnace. Recently I had my furnace repaired (faulty igniter) and the HVAC technician ...
0
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0answers
53 views

Why is my heat not shutting off at the set temperature?

When I turn the heat on on my central heat and air unit, the heat came on then continued to run getting really hot. It would not shut off unless I turned from auto to on then back. Sometimes I had to ...
3
votes
2answers
159 views

Can 2 - 6“ flex ducts be combined into a single 8” rigid duct

I'm trying to clean up some sloppy HVAC work in my home prior to finishing my basement. I have 2 VERY long 6" flex duct runs coming off the supply master that feeds the great room in my house. Both ...
1
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2answers
128 views

At what temperature does a WiFi thermostat stop sending a signal to the router?

I recently purchased and installed a Honeywell WP6500 WiFi thermostat and thanks to Stack Exchange, got it up and running. I have a house in New Hampshire, which I use occasionally during the winter. ...
2
votes
1answer
47 views

Is the furnace undersized?

I have a 2700 sq ft rambler home with cathedral ceilings over a large portion of it - over the hallway, 2 living rooms and kitchen. We replaced the furnace that was installed when the home was built ...
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0answers
16 views

Goodman heat pump in SC freezing up at least monthly

Identical units in new neighborhood but my unit is the one freezing up excessively and has shut down completely. HVAC installer says everything is normal but when your heat shuts off until you ...
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1answer
15k views

Why won't my A/C turn on after I replaced the thermostat batteries?

Our thermostat died yesterday, but after replacing the dead batteries with fresh batteries, and confirming the LCD screen was operable, our AC no longer turns on. I have attempted a factory reset on ...
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0answers
54 views

Diagnosing boiler problem. Strange noise and pressure released

Woke up to a loud almost grinding noise coming from all the radiators/pips in my hot water heating system. It's intermittent, every few seconds but the system is generally running louder than normal. ...
4
votes
4answers
328 views

Can I reduce static pressure in one room by adding a vent to an adjoining room?

Our return vent for our hvac is right outside the master bedroom. The master bedroom gets very little airflow with the door shut. It was recommended that we add secondary return duct in the master ...
0
votes
1answer
169 views

Do I need a sleeve for through the wall air conditioner in new construction?

I am about to buy a through the wall A/C unit for a small building, which the builder will frame out for the A/C. Is the framing enough, or do I need to buy a sleeve for A/C?
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4answers
494 views

Is there a special low temperature thermostat?

I have a gas ceiling mounted furnace for my garage. I want to set my garage at 35-40° F (1-4° C). Is there a special thermostat to control furnace at that low temp? (I've seen one works as low as ...
1
vote
1answer
583 views

Can I convert a window A/C unit in to a pool-water cooled system?

I have an 18,000 BTU A/C unit that blew a compressor last year. Perfect for a small project. I however could not find a professional to help me out, so maybe it's DIYable. I know just about enough ...
6
votes
1answer
298 views

Orange flame on all appliances

I have an orange flame in all my gas appliances (gas furnace, gas water heater, and gas stove) and cannot seem to determine the cause. Background So far, I have had the gas company come out. I had ...
1
vote
1answer
79 views

Bathroom, dryer and central vac - Can any of the exhausts be combined, and can any use the same penetration?

I have these three units within 5 feet of eachother. The place where the bathroom vents to is the only place within reach to have a penetration to outside. My options are to stack these three ...
0
votes
1answer
283 views

Thermostat C-wire replacement using a wall socket?

I have a Filtrete 3M WiFi thermostat. As expected, it takes a C wire, which my apartment doesn't have and the apartment maintenance folks wont' let met wire either. However, there's a wall socket ...
2
votes
1answer
154 views

Breaker box or heat pump problem?

We ran our forced air heat pump today. 15 min. in we noticed it just stopped running. Looking in the breaker panel I could see that the breaker for the heating unit had tripped. When I tried to ...
0
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0answers
152 views

Why would said gas furnace keep shutting off?

Seems that I have a gas furnace that is having some sort of heat/air sensing issue. Basically it shuts off after running for a minute or two. But if I remove the top plate of the furnace itself it ...
7
votes
4answers
3k views

Can I modify the vent from my high efficiency furnace to prevent possible damage to the exterior of my home?

is my high efficiency furnace vent installed properly? I'm based in Toronto, Canada. In some recent cold winter weather, the exhaust is causing a lot of ice buildup on the surrounding brick. To my ...
1
vote
3answers
413 views

Should I leave the fan switch on my thermostat set to fan rather than auto?

I purchased a new Amanda Furnace in Oct'2013. I am told in order to maximize a warm, consistent room temperature I should set the thermostat to the Fan position rather than the Auto position. Does ...
3
votes
2answers
1k views

Is voltage too high in C wire going to thermostat?

I've managed to add a C wire to my thermostat. I then decided to check the voltage between the R and C wires, and find that it read as 27.8 volts, not the 24 volts it was supposed to be. Could this ...
0
votes
1answer
143 views

When should HVAC returns be opened and closed?

My Pennsylvania house was built in the early 90s, has central heat (natural gas) and central A/C, and most rooms have pairs of closable air returns on the wall near the floor and ceiling. I've been ...
0
votes
1answer
28 views

Why isn't my aircon blowing cold air?

I have 2 x 9000Btu split aircon installed in my house three days ago. In fan mode it works properly but when I switch to cooling mode the upper pipe from the outside unit freezes immediately, not cold ...
2
votes
2answers
327 views

Air conditioner not blowing cold air

My HVAC system had a problem during the winter where the blower motor stopped working. I got a HVAC tech to come out and replace it. However, now that it's hot again, the cooling system is still ...
1
vote
1answer
961 views

How can I figure out why the low voltage furnace fuse blows on heat but not cool?

I have a Tempstar Model NTC6100KFG1 gas furnace. Furnace was working fine through the summer blowing the AC. It's been off for a month or two as we've been changing seasons here. When I went to turn ...
0
votes
1answer
456 views

How do I connect a WiFi thermostat to my furnace's primary control?

I would like to install a Honeywell WiFi controlled thermostat to connect to a Honeywell R7184U primary control. My question concerns the "C" wire. The R7184 has the terminals labeled 1, 2, 3 and 4 ...
3
votes
1answer
158 views

180º/gooseneck/u-shaped cold air return?

I am in the planning stages of moving a cold air return from an inconvenient spot in the floor to a nearby wall. The basic plan is to open up the wall on both sides (cutting one stud and framing in a ...
3
votes
3answers
956 views

How can I cut a cinder block wall to run large round duct through it?

When an addition was put onto the house that I own, the previous owner just ran the duct work into the crawl space through an old basement window. I want to re-route the duct work by actually cutting ...
0
votes
1answer
88 views

What is this fabric tape made out of?

Any ideas what is this fabric tape on my cool air return ductwork? High res close-up Some of it is separating or worse falling off of the duct work on the cool air return to my forced-air gas ...
1
vote
1answer
88 views

Propane HVAC system - convert to use wood burning stove?

is it possible to remove the propane part of the HVAC and replace it with a wood burning stove? If so what would I have to change - eg the chimney etc etc?
0
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0answers
35 views

How do I fix a blower fan snap disc that opens too soon?

My fan limit thermodisc opens too soon and shuts the fan motor down after the gas burners ignite and runs for about 2 minutes. I replaced the limit switch and still have the same problem. How do I ...
0
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1answer
117 views

I just had a heat pump installed. I had central air already so the duct work was there already for a/c. Should my vents in the ceiling be changed?

One person told me I need to change my Registers on the first floor that are in the ceiling because the house was set up for air not heat. They say the Registers I have keep the cold air going a ...
4
votes
3answers
2k views

How effective is a heat pump for AC and a heat pump/furnace for heating in New England?

We currently have a central AC unit and oil furnace. The AC is broken and the furnace is old, so we are thinking of replacing both sometime in the next year. We are considering replacing the AC with ...
2
votes
2answers
237 views

Furnace flashing 4 times (Ducane)

My Ducane furnace flashes 4 times, runs for 5 minutes, and then the burner goes off. When the limit switch is jumped it runs good. What needs to be changed here?
0
votes
3answers
385 views

extra thermostat, electric dampers and 1 furnace [duplicate]

I have a problem similar to others that have posted: balancing heating/cooling throughout the house. I have already played with adjusting the vent's air flow as well as the manual dampers in the ...
0
votes
1answer
364 views

can i use an inline exhaust to vent a kitchen and bathroom?

I have 2 bathrooms and a kitchen that are currently unvented. I would like to install an inline exhaust fan to service all three. I will be putting the exhaust fan just inside a gable that will have ...
0
votes
2answers
2k views

How do I connect the common wire in a Carrier air handler?

I am trying to install a new wifi thermostat in my home and need to locate the common terminal for my air handler. I have a Carrier model FB4CNF030. It's a new construction home and I have the blue ...
12
votes
6answers
583 views

Is it worthwhile to have ductwork cleaned?

Was rearranging some ductwork in my basement, and noticed that the stuff I took down was pretty filthy inside (especially the return air ducts). Is it worthwhile to have ductwork cleaned out? What ...
4
votes
1answer
192 views

How can I determine if my HVAC system has features which are not currently wired to my thermostat?

I recently upgraded to a Nest Thermostat. This new thermostat supports many more terminals and features than my previous thermostat. My old thermostat had the basic terminals; G,R,C,Y, and W. I am ...
1
vote
3answers
90 views

can I install a new thermostat by just turning off the power instead of turining off the circuit breaker?

Can I install a new thermostat by just turning the power off at the servicemen's switch, instead of at the breaker?
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2answers
1k views

Controlling separate heat and AC devices from a single thermostat

I have hydronic radiator heat powered by a gas furnace situated in one mechanical room of my house and a currently being installed central AC whose air handler is situated in another mechanical room ...
1
vote
2answers
1k views

Can a boiler water feed / pressure relief valve be repaired?

I am a homeowner trying to troubleshoot my hot water boiler system (Winkler Gas Boiler). I noticed recently that my boiler is reading zero pressure. The combination fill & pressure relief valve ...
2
votes
1answer
1k views

Is it normal for A/C performance to improve when vent covers are removed?

I recently moved my office to the second floor of our home and I haven't been able to get the temperature below about 78 even though the thermostat is on 72. My son's bedroom had been the same way ...
2
votes
2answers
783 views

Recommended proximity of HVAC vent to return air

I have an upstairs room with an HVAC vent in the ceiling above the door. The return air is in the hallway just outside of the same door. This room also happens to be the hottest room in the house (by ...
0
votes
2answers
242 views

HVAC air handler with a built-in humidifier

I am in the process of choosing an air handler to use only for AC. I plan to keep radiant heat. However, in the winter, I would like to use the AC system to blow humidified air to compensate for the ...
0
votes
2answers
319 views

Why doesn't my gas furnace ignite?

I had a Lennox slp98dfv installed last year - it has a surelight ignition - it now just blows cold air - so I assume the pilot light is out - but not sure how to light it - as u cannot manually ignite ...
3
votes
1answer
613 views

Why would my Goodman gas furnace start but not stay on for more than 2-3 minutes?

I've got a problem with my 15 year old Goodman furnace. It starts w/o problem, inductor begins working, hot surface ignitor lights up and ignites the gas. Then the main blower starts working and the ...
2
votes
2answers
112 views

How to measure air flow coming out of registers?

As my contractors finish installing ductwork and the air handler for my central AC system, I would like to have a measure of how many CFMs come out of each register, as a function of how the system is ...