29 year old HVAC systems - add soft start?

Users who are viewing this thread

TurboMan

Member
Messages
46
Reaction score
7
Points
8
Location
Illinois
Just had two 29 yo Heil 5000 series HVAC systems (4 ton and 3 ton) serviced. Both were OK on freon but he measured the resistance of both of the compressors and both had higher values than they should - so consequently drawing more current. Said both of the caps were going bad as well - probably because of the higher resistance compressors.

We know they need to be replaced but do not have the funds to do it this year. Definitely next year. Already ordered the caps and was thinking of adding soft starts to both systems which can be repurposed to the new systems next year.

Would a soft start help prolong the life of a failing compressor? Would a soft start even work on a compressor that consumes more current than normal? To me it sounds like it would be an issue but wanted to ask the experts.
 

Breplum

Licensed plumbing contractor
Messages
2,565
Reaction score
1,099
Points
113
Location
San Francisco Bay Area
not a lot of experts on that subject here. I had a HVAC license but not trained myself on refrigerant systems...hired it out to experts.
Wait and see if anyone pipes up.
 

Jeff H Young

In the Trades
Messages
9,803
Reaction score
2,481
Points
113
Location
92346
there is hard start kits and soft start kits , but the most important thing is to seperate the home owner from thier money Just kidding but Id be lying if I didnt think upselling wasent a big part by some of those companies. First Ive actually heard of the soft start I thought it was just another name for the same thing as a hard start
 

TurboMan

Member
Messages
46
Reaction score
7
Points
8
Location
Illinois
Contacted the manufacturer of the soft start I was going to buy. Gave him the model numbers of the condensing units. He said they have reciprocating compressors and modern condensing units use a new type of compressor. There are different soft start modules needed for both. He suggested not bothering if you are going to be replacing them next year. We will just wait until we get new systems.

Hopefully this will help others.
 

Jeff H Young

In the Trades
Messages
9,803
Reaction score
2,481
Points
113
Location
92346
Contacted the manufacturer of the soft start I was going to buy. Gave him the model numbers of the condensing units. He said they have reciprocating compressors and modern condensing units use a new type of compressor. There are different soft start modules needed for both. He suggested not bothering if you are going to be replacing them next year. We will just wait until we get new systems.

Hopefully this will help others.
Good luck dont know if you read my other post regarding " HARD START " kits evedently they are differant than a soft start kit I really dont work on these systems kinda think a lot of Techs up sell Like snake oil salesmen . but dont know what to belive . So I dont think the post really helped much other than to suggest looking into upgrades befor you jump
 

TurboMan

Member
Messages
46
Reaction score
7
Points
8
Location
Illinois
Good luck dont know if you read my other post regarding " HARD START " kits evedently they are differant than a soft start kit I really dont work on these systems kinda think a lot of Techs up sell Like snake oil salesmen . but dont know what to belive . So I dont think the post really helped much other than to suggest looking into upgrades befor you jump
My understanding is soft starts serve two purposes. They lower the current requirement to start the compressor which allows the condensing unit to start with smaller size generators (ex 4000 watt). They also extend the life of a healthy compressor by not slamming the motor windings with excessive current.

From what I read hard starts provide more current to the compressor coils to help already failing (high resistance windings) compressors. That's why I was asking if a soft start would even help our situation. The HVAC tech said both of these compressors had high resistance and both caps were failing.

He said replacing the caps might help then survive for the year. For $25 I will give it a shot.
 

bukzin

New Member
Messages
11
Reaction score
2
Points
1
SoftStart (AKA easy-start, etc) units have been around in one form or another for decades.

Some folks in the HVAC world tend to avoid things they do not understand. We have installed several on old central systems
and have been very happy with both the power (current) savings and lower start up noise.

Service calls are expensive compared to the installed cost of these units.
 
Top