New Air Conditioner / Heat Pump Won't Start FAQs

Q&A about a brand new A/C or heat pump system that won't run.

New Air Conditioner or Heat Pump Won't Start FAQs

New compressor installed; everything is running, but no cold air.

New compressor installed; everything is running, but no cold air. Freon is full. On 2019-07-04 by Pat Stroschein

Reply by (mod) -

Surely when you have just paid a big bill for a new compressor motor if you call the repair company your installer will return to diagnose and fix the problem.

An example of what could go wrong would be inadequate vaccum time or cleaning of the refrigerant piping or tubing when the new compressor motor was installed or failure to install a compressor burnout filter drier on the refrigerant line to catch the inevitable debris that forms in the refrigerant lines as the new compressor tubing is brazed in place.

That debris can clog a capillary tube or thermostatic expansion valve that then could prevent refrigerant from reaching the evaporator / cooling coil in the indoor air handler.

Really? Yes BUT first be sure that we're not looking only at the outdoor compressor/condenser unit.

Be sure that power is on to both the outdoor compressor condenser unit AND at the indoor air handler, fan/blower unit.

A/C worked just intermittently; Put in new A/C system; same problem.

A/C works intermittently. Will work fine for a few days and then just start blowing uncooled air.

When heat pump blows uncooled air it begins making metal on metal loud sounds. If I shut it off for a few hours and turn back on it works fine. Have had 4 visits from technician to determine problem.

Was told I needed new heat pump. So we put new one in. Same problem is still occurring. A/c running intermittently and heat pump making metal on metal sound when air is no longer being cooled.

They have checked pressure, air handler , freon, circuits, etc. please help me. This has been going on for 3 weeks now. It is 95 degrees currently. On 2016-06-06 by Paula

Reply by (mod) -

It's not clear to me why the need for a new heat pump would result in an intermittent problem, Paula.

Seems to me if the heat pump - presumably the compressor mortor - has failed, it would fail consistently.

More likely there is a problem with a

• control board
• control relay,
• wiring connection
• supply voltage
• a fan or compressor motor that is having trouble starting or has a bad start capacitor
• something else I've forgotten to list

Call your HVAC service company manager, calmly discuss the problem with him/her, and ask for help from one of their senior, experienced techs. Keep us posted.

I can't get my air conditioner to turn on - I can't afford to hire a repair technician

I recently moved to a home with an hvac heating and cooling setup, which ive never had the pleasure of having.

anyways , all summer my air conditioner hasnt worked. the house sat empty for 2 years but the furnace works and kicks on . I have an air temp type central air conditioner that sits outside.

Im sure the weather may have something to do with it . ive tried the breakers, fuses, thermostat, checked all incoming electric and all are working.

It simply wont turn on, I know its not the fan because it turns and the bearings are good. on the control board mounted on the upper side of the unit , the led light is flashing 6 times, repeatedly. I troubleshooted online and it says it could be the blower motor amongst other diagnoses that we have tested. I also reset the system, breaker, thermostat and still nothing.

However, im not sure the air filter is clean , but ill check that next. does anyone have any suggestions or advice because I cant call a specialists because its wayyy too much money. has to be done by my husband and I . any help is appreciated ! thanks ! - On 2020-09-14 by amber mac

Reply by (mod) - be sure power is on, starting at the breaker or fuse panel and at the outside and inside service switches by the units

I'm so sorry Amber,

Generally you need a trained HVACR repair technician to fix an A/C unit if the obvious checks that can be done by a homeowner are fruitless.

Once you've confirmed that the power is on to the equipment and that the thermostat is set to COOL and is set to a temperature well below existing room temp, if the AC won't run a tech will need to check the control board, relays, and possibly refrigerant charge; that requires both training and special equipment.