Recently-Asked Questions (and answers) about air conditioners & heat pumps, set #6

These FAQs about air conditioning and heat pump systems help troubleshoot and repair AC and heat pump systems.

These FAQs are part of an article series discussing how to inspect and repair all types of residential air conditioning systems (A/C systems). Page top image provided courtesy of Carson Dunlop Associates, a Toronto home inspection, education & report writing tool company [ carsondunlop.com ].

Recent Air Conditioning & Heat Pump FAQs #6

These questions & answers about air conditioning & heat pump systems were posted originally at AIR CONDITIONING & HEAT PUMP SYSTEMS - home

Schematic: sequence of electrical tests useful in troubleshooting air conditioners and heat pumps.

[Click to enlarge any image]

On 2018-04-12 by (mod) - I'm afraid to repair the air conditioner myself

Jack

A homeowner can sometimes find and fix certain problems with air conditioners and heat pumps such as a blocked or dirty air filter or can diagnose others such as leaky, damaged ductwork.

But work that involves more complex diagnosis of a compressor motor, refrigerant metering devices, finding refrigerant leaks, or charging a system require special training and equipment.

That's also the case for installing new air conditioning equipment excepting portable systems such as a window A/C that is simply brought home, installed in a window with proper support, and plugged-in.

On 2018-04-12 by (mod) -

Jack said:
Thank you for a very useful article. I'm afraid to repair the air conditioner myself, so it's better to ask for help from specialists.

I had a bad experience trying to repair AC myself. I repaired it, but after a while it broke down anew, and it was not possible to repair it and it was necessary to change it completely.

If you are not sure what you can fix, better find a contractor. Well, now they can be ordered anywhere, even on the Internet you can choose by the price and reviews.

On 2018-04-10 by (mod) - moldy A/C system - mildewy, musky, dirty sock smell

Kimberly

I would stop using the AC - the mold odors you describe, including the dirty-sock smell (also possibly a mold) can be a respiratory irritant and a potential health hazard, especially to people at extra risk (asthmatics for example).

The solution is to

1. find and remove the mold problem

2. find and fix the leak or moisture source that caused it

Ozone generators are a risky approach. See OZONE MOLD KILL TREATMENT - https://inspectapedia.com/mold/Ozone_for_Mold_Remediation.php

And the fantasy that cheese cloth or any other coating is complete and long term reliable to encapsulate mold in duct work is not, in my opinion nor experience something in which I'd have confidence.

If the ducts are metal-interior they can be cleaned. If not, unfortunately, I'd consider that the replacement advice you heard was reasonable.

Keep in mind that if you eschew an expert and thorough home inspection (by an inspector who has no conflict of interest and who is working just for you), your risk other costly surprises after you buy a home. An occupant will often know things about a home that are not obvious to an inspector, but the inspector has an experienced eye as well as training that usually spots things you might want to have known.

On 2018-04-10 15:54:33.455848 by Kimberly

Help! I just moved in to a house I'm buying and when the a/c blows it is a mildewy, musky, dirty sock smell and I've been sneezing, coughing and my throat is sore every day.

My son is displaying the same symptoms. The home inspector said that the ducts are dirty and need to be serviced/cleaned by an HVAC company. Some of the ducts are fiberglass-lined and some are flex duct so they cannot be cleaned.

I had an HVAC company come take a look and they're suggesting an installed ozone cleaner in the system for $1200 and maybe some cheese cloth in the vents to prevent fiberglass and dust particles from blowing out. Ultimately the guy said the ducts need to be replaced and the entire system since it's already 7 years old. Please help! Should I move out of this house and find something else? I am renting it until the closing because the roof wasn't done in time to close. So that's why I'm living here before buying.
It's a 1958, 1200 as ft house, 2011 3-ton unit.

On 2018-04-04 06:01:04.550003 by Veba

Dear all

I have a problem with my blower unit.we arent able to completed our air balancing. Its indoor unit and we installed at the outside of the serving room(because of consultant). Total designated air flow is 1505 L/s but we are getting 1152 L/s. we setted to pulley and cleaned to filter but still we are getting less flow. we need minimum 90 percentage but we are getting 77 percentage. What shall i do more? an you help me.

On 2018-03-09 22:35:34.096656 by (mod) -

Arlene

Check out the table of AC sizes at BTU CHART for AIR CONDITIONERS / HEAT PUMPS at https://inspectapedia.com/aircond/Air_Conditioner_BTU_Size_Chart.php

On 2018-03-09 00:48:09.837659 by Arlene

How many BTUs needed to air condition 900 square feet home?

On 2018-03-03 19:01:38.553305 by Cherian

Johns & Beth, please find some time today to talk about the BMR property available for rent/ purchase at San Carlos.

If one of you are busy with children, the other may talk to us between 7 pm to 12 midnight our time; FT or phone. If we have any plan to give a try, we may start the discussion today, pool all our questions together which I will ask the SC city town planning coordinator tomorrow. If I can sell our FL condo and put that amount as cash down towards buying the 3/2 apt.

With 1400 sq.ft, that will be good.

Even if it is for a much reduced rent, about 2000 a month, that would be fine too. Another idea is for you to register tomorrow and be in the waiting list which may give us some advantage/ benefit. Anyway, you don’t loose anything. Please discuss it between the two of you.

On 2018-02-27 23:32:32.437661 by (mod) -

Thomas

As the tech replaced the start/run capacitor and that didn't do the trick I suspect a failing fan motor or bearing.

On 2018-02-27 13:07:12.861126 by Thomas

My heat pump system runs fine when heating the house, but if I turn the a/c on the outdoor fan will not work. It hums and is even hard to get going if using a stick to turn it. Technician replaced capacitor last week. Thanks,

On 2018-01-17 16:52:26.923071 by (mod) -

No David.

On 2018-01-17 16:52:19.086830 by (mod) -

david said:
do you know this company - Green Leaf Air

On 2018-01-11 23:24:30.007224 by (mod) -

DB

Assuming you're talking about the fan in the indoor air handler, since it's the same hardware used in both cooling and heating, I'm puzzled too. What's different is only the temperature in which the fan is operating. Perhaps there is a lubrication or bearing failure that's exacerbated when the blower assembly is hot.

On 2017-12-20 21:15:23.658157 by devilbear1972

I have a Goodman heat pump when the AC is on the fan works great when the heat is on it sticks and starts to overheat what could be the problem

On 2017-11-20 18:58:31.294855 by (mod) - refrigerant leak of a 3 year old 410A heat pump.

Bob

It can be very difficult to find a small, slow refrigerant leak with or without a refrigerant gas detector. The leak can be in a spot that you cannot place the detector tip.

However you can sometimes spot a leak by visual means, noting refrigerant oil stains on a refrigerant line or at a fitting (dark oily residue).

It would be unusual to find refrigerant in a condensate drain itself but if indeed you're detecting refrigerant gas at the drain line opening at the evaporator that says it's time to check the evaporator coil and piping and fittings around it more closely.

On 2017-11-11 05:13:43.077238 by bob white

I have a refrigerant leak of a 3 year old 410A heat pump. It's losing about 1 lb. per year.

I bought a halide leak detector and went over the whole system and the only alarm I really got was inside the condensate drain line opening of the evaporator.

Maybe a smaller alarm around the inside of the coil but couldn't pinpoint it or get the same area twice. Would this alarm inside condensate drain line be refrigerant leaking off the evaporator into the condensate ?

Because I've went over all the fittings, valves,solder joints with soapy water too and found zero. I've also got 30 year old freon lines that were not replaced inside the outside wall & into the attic and I just felt around them with my hand and didn't feel anything wet or oily.

I've got a 10 year warranty on the system so I think I'll replace the evaporator and refrigerant lines because I just pay labor and I know someone that does this reasonably and feel 90% this is problem from what I've heard of evaporator coil problems in this industry. Thank you, Bob W. 11/10/2017

...

Continue reading at DIAGNOSTIC GUIDE A/C or HEAT PUMP or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Recommended Articles

• AIR CONDITIONING & HEAT PUMP SYSTEMS - home
• AIR HANDLER / BLOWER UNITS - home
• COMPRESSOR / CONDENSER REPAIR - home

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