Basic expectations of HVAC technicians

[Stormking]

  So I had an HVAC guy over because my Split furnace wasn't working,  and they diagnosed it as a blown control transformer tested the air temp  and made assorted comments about air temperature cleaning ac coils and squirrel cage blower ect and how my furnace was getting on in years and so forth. This is good and proper I feel.  However 2 days later it was warm enought to want to put on the AC so tried to turn that on.  Hmm  it's dead again. won't blow the fan ect.  So with my trust nose and magic circuit breaker I found the problem rather than pay another callout fee of 90$ + whatever extra it takes them to figure it out.  It's another blown transformer. and after buying an extra transformer from the parts hut and wiring in a 1Amp fuse I discovered that it's the AC control circuit to the AC contactor that is the short(1 OHM instead of 20OHM across the contactor coil).  And have since replaced them.

  Now is it too much to expect an HVAC tech upon discovering that there is a blown transformer for your basic 4 wire theromstat/furnace to test all 3 circuits ( fan,heat,ac) to verify there isn't a failure there that would cause it to blow again?

Oh and why don't they put fuses in all the control transformers.

[dkpd1581]

A 1 amp fuse will most likely be to small a fuse for a 40VA transformer.  I would suggest a 3 or 5 amp car fuse or glass fuse.  You will have nuisance trips with only a 1 amp installed.

Many techs know mechanical, many are parts changers, many are paid for selling versus fixing.  Those who do fix and do a good service for the customer are not rewarded when the raises/reviews comes around they also realize smaller bonus/commission checks.  Yes they fixed your stuff; however, they did not generate a lead and did not produce a profit as high as a replacement and in the eyes of the Company they are not as valuable a tech.

Many techs do not know or understand even the most elementary electrical theory.  They are unfamiliar with their meters so as not to understand how to use it or interpret what it is telling them. Its a simple fact that most service calls (say around 80%) are electrical in nature.  If you do not understand electrical, you replace bad parts until they get it right or sell you a new one; a sad simple fact.

Are you expecting to much? NO.  Should you expect that much? YES.  Will you get what you are expecting and paying for?  MAYBE.

As to the fuses at the control transformer, they are made that way. As to why they all do not have them - COST.  You can save a few dollars and take a chance without one or realize value, make the investment, and pay the extra money for one in the transformer.  I have seen sales lost for as little as a $10-$20 difference in one unit to another.  The difference in the units was the slightly higher one HAD the fused transformer and HAD the safety pressure switches that the other did not.  A 12 pack of beer and pack of cigarettes investment passed over in favor of the 12 pack of beer and the pack of cigarettes.  Inexpensive choices with serious consequences.

Call the Service Manager of the company that serviced your unit, raise Cain, get your service charge back. Don't talk to a Dispatcher, don't talk to the Office Manager, speak only to the Service Manager or Owner. State your case very succinctly and matter of factly. Tell them that for $90/visit that you expect and deserve more and did not get it.  Ask for a refund of the entire amount you paid.  Chances are good that you will get it back.

[Stormking]

I realize that a 1Amp fuse is probably too small for a 40VA( but thanks for pointing out incase I didn't), I just used it because even though a 2 amp fuse is technically to large for a 40VA transformer ( 24v * 1.666A = 40VA) and would probably still be fine since what would probably burn out the transformer is a probably a much large draw than 2 amps, and the transformer probably wouldn't burn out at 2 amps for a while, I wanted to be conservative while testing.  And in any even the transformer that was used before was a 30VA transformer.  My longer term plan is to stick the proper size transformer ( already ordered) back in with something like a 2-3 amp fuse.

  As for why  the transformers don't have fuses in them,  I don't disagree with your analysis in addition  Since the parts aren't really intended to be user servicable, what's another 20$ on top of a callout fee anyway, since often if the draw is bad enought to pop the fuse, it's probably not a transitory issue that sticking in a new one would fix it and you would need to call an HVAC tech.  I still think that it's poor design and wasteful, but yeah a 12 pack of beer is a might fine inducement.