HVAC question - am I being told correctly by contractor?

[sh00ter]

Newer York unit still under warranty, fan on top of the unit was buzzing and coming on repeatedly over and over again constantly...the buzz reminded me of the sound when a capacitor is bad...it dimmed the lights in the house each time it turned on and then ran for 30sec and then repeat...this went on for a long time (days, maybe weeks)but at other times of the day it seemed to run normally and when the guy came to look at it, it didn't do it. He said (based on my description) it sounded like it was bouncing off the high-side pressure switch but I myself wonder why would it do that if it shut off almost immediately after it would start. I would think the pressure would take longer to build up...the house was cool the whole time this was going on so it still worked but was annoying and undoubtedly all that struggling to start the fan was using some electricity.

Their solution was to swap the expansion valve for an orifice tube but they said we'd lose some efficiency...this doesn't seem right to me that we should have to accept that?...They also told my wife that they had checked the freon and stuff and it was okay; why would it bounce off the high-side switch if it wasn't over charged? It hasn't been that hot and this "fix" was done over a week ago anyway so we were barely into summer. I need experts to chime in and either make me feel better about what they did, or tell me what to do. I know some about automotive A/C but not too much about home.

Thanks

 

[saddlebum]

Compressor struggling to start,fan motor would never pull enough amps to dim the lights. Hard start kit

 

[Mr.Glock]

Starting Capacitor is weak or gone bad.

 

[saddlebum]

expansion valve could be going bad and sticking closed.which would mean new valve not get rid of valve altogether. there was a rash of valves sticking that trace back to a coating the compressor companies were using that turned in to brown goo when mixed with compressor oil.it would gum up txv's (expansion valve) the cure for for that was an additive poured in to system and a new valve

 

[red dirt okie]

Newer York unit still under warranty, fan on top of the unit was buzzing and coming on repeatedly over and over again constantly...the buzz reminded me of the sound when a capacitor is bad...it dimmed the lights in the house each time it turned on and then rand for 30sec and then repeat...this went on for a long time (days, maybe weeks)but at other times of the day it seemed to run normally and when the guy came to look at it, it didn't do it. He said it sounded like it was bouncing off the high-side pressure switch but why would it do that if it shut off almost immediately...the house was cool the whole time this was going on so it still worked but was annoying and undoubtedly all that struggling to start the fan was using some electricity.

Their solution was to swap the expansion valve for an orifice tube but they said we'd lose some efficiency...this doesn't seem right to me...They also told my wife that they had checked the freon and stuff and it was okay; why would it bounce off the high-side switch if it wasn't over charged? It hasn't been that hot and this "fix" was done over a week ago anyway so we were barely into summer. I need experts to chime in an either make me feel better or tell me what to do. I know some about automotive A/C but not too much about home.

Thanks

Just had the same issue with my system today. Found out that the sealing tape had come loose due to high humidity, and that is what caused the buzzing sound. As for lights dimming, that has not happened yet. My air guy then told me, if I want to keep the warrenty going, I need to buy a maintaince contract through him for 169.00 a year. Get a second opinion, and tell your air guy, that you are doing so.

 

[sh00ter]

Well full disclosure is that this is a new house and the unit is under warranty with the A/C people that installed it but it is also still under builder warranty. But when we told the builder, they told us to just call the A/C people. I figured we were getting screwed...so it sounds like they did the "sure fix" so if the valve was sticking it would not happen anymore? How would adding the orifice tube make me lose efficiency and how much would I lose?

 

[Viper16]

Sounds like he wants to go from a modulating expansion valve to a fixed orifice style....you will lose some efficiency in your capacities as it will not modulate based on head pressures. If the valve gets stuck and high pressure is built up, the condenser fan is trying to cool the refrigerant...if it can't then the high limit trips the whole unit off, it resets thermostatically and then tries again to turn on...it builds heat, you get that on/off/on/off cycling...very hard on the compressor.

if the compressor starter capacitors are shot (OR loose wiring can cause the trouble), then the unit would be buzzing and slamming it self on at times, and could try multiple times...I have heard a few in my neighborhood in the middle of the summer, such a nasty sound.

Could be a compound issue, with the high limit tripping and the compressor shutting off and capacitor not having enough charge time for the next start, and bam the hard start of the compressor, and the on/off cycle it produces.

 

[Lurkerinthewoods]

I'm sorry, but there is no way in hell I would settle for a "fix" on a new unit in a new house. Make it work like it did when it was new, or replace the entire unit. If the builder won't step in, call the company that underwrites the builders warranty. If that doesn't work, call the company that made the unit and explain to them what this AC guy is trying to do.

You should only settle for a "fix" when the unit is out of warranty and you are trying to buy some time until you can properly fix it.

 

[sh00ter]

Sounds like he wants to go from a modulating expansion valve to a fixed orifice style....you will lose some efficiency in your capacities as it will not modulate based on head pressures. If the valve gets stuck and high pressure is built up, the condenser fan is trying to cool the refrigerant...if it can't then the high limit trips the whole unit off, it resets thermostatically and then tries again to turn on...it builds heat, you get that on/off/on/off cycling...very hard on the compressor.

if the compressor starter capacitors are shot (OR loose wiring can cause the trouble), then the unit would be buzzing and slamming it self on at times, and could try multiple times...I have heard a few in my neighborhood in the middle of the summer, such a nasty sound.

Could be a compound issue, with the high limit tripping and the compressor shutting off and capacitor not having enough charge time for the next start, and bam the hard start of the compressor, and the on/off cycle it produces.

thanks for the detailed opinion, and thanks to the others too...now that the thing has the orfice, how would I know if the compressor or capacitor or other components were worn from who knows how long this went on...this house was done last summer but it took them until April for us to move in since the builder was so poor (and his subs)...this is just another kink in the chain for a long list of problems but my point is, this actually could have been how it was from day 1 after the HVAC system was installed and we only noticed once we started using it in may after we moved in... could have been doing it a few days or maybe even months total of use like this...I just do not know but I am concerned it shortened the life of something.

I'm sorry, but there is no way in hell I would settle for a "fix" on a new unit in a new house. Make it work like it did when it was new, or replace the entire unit. If the builder won't step in, call the company that underwrites the builders warranty. If that doesn't work, call the company that made the unit and explain to them what this AC guy is trying to do.

You should only settle for a "fix" when the unit is out of warranty and you are trying to buy some time until you can properly fix it.

They (A/C company) said this only happened on one other house"...I plan to make a stink about it now but they cant do any thing right...NONE of their subs...it is a reflection of our society today.

 

[Lurkerinthewoods]

thanks for the detailed opinion, and thanks to the others too...now that the thing has the orfice, how would I know if the compressor or capacitor or other components were worn from who knows how long this went on...this house was done last summer but it took them until April for us to move in since the builder was so poor (and his subs)...this is just another kink in the chain for a long list of problems but my point is, this actually could have been how it was from day 1 after the HVAC system was installed and we only noticed once we started using it in may after we moved in... could have been doing it a few days or maybe even months total of use like this...I just do not know but I am concerned it shortened the life of something.



They (A/C company) said this only happened on one other house"...I plan to make a stink about it now but they cant do any thing right...NONE of their subs...it is a reflection of our society today.

When we were building our first house back in 06, me and my son was in one of the bedrooms insulating the interior walls before sheet rock went in. The AC guys were installing the furnace in the attic by lifting it up through the living room ceiling. We heard a loud noise and when we came into the living room the guys were looking at the furnace laying on the slab. Apparently while lifting it up into the attic (we have 10ft ceilings) the guys in the attic dropped it. We just stood there from a distance watching them look the unit over and to my surprise, they started lifting it back up to the guys in the attic. This is about the time I went ape chit on them, but they assured me it was fine and if it wasn't, it was covered under warranty.

I told these fools that furnace wasn't going in this house and I called the company and informed them they had better get a new unit out here that day.

there are a lot of contractors that care about the quality of work they do, but there are a lot of contractors that are only in it for a job and couldn't care less about the quality of their work. I hope this works out for you.