Calling all heating and air conditioning mavens...

In My Humble Opinion
1

I am going to have to clal upon the services of such a person and I believe that the profession is rife with crooks, much as the auto mechanic profession is rife with crooks.

I can’t seem to get a good recommend for a trustworthy and reasonably priced sort, so I want to go in armed with as much information as possible.

Knowing that my problem cannot be diagnosed via the web, I’m just looking for some ideas about what might be the issue.

I have a rooftop unit. The heating and the air both come through the same vents, which are evaporative cooling vents that were adapted for the AC and heat. It’s gas heat.

There is a large intake in the hall that requires a filter change and needs one very much right now. The thermostat is in the hall and it has a digital readout, I can set it for manual fan or auto fan + heat/cool.

A couple of months ago when we had what passes for a cold snap in California, the heater stopped working. No matter what I did, I could not get it to come on. I could turn on the fan, but no heat. I could hear the “click” in the thermostat that sounded like it was trying to turn on the heat, but no heat happened. I turned it on, off, up, down, nothing. Then I tried the AC and that DID work, but I quickly turned it off because it was very cold.

I left it set to go on and about 36 hours after it conked out it suddenly kicked in and it has worked perfectly ever since, it was just like a little vacation day or something.

Okay so now we’re having our first “hot snap”. I flipped everything over to AC and it SOUNDS like it’s working, but it’s not. the air is pushing through (although not very well and I think a filter change would help there) and the thermostat “thinks” its kicking on (unliek the heating) but he air getting pushed through is warm.

So, any ideas? Any ideas that would preobably be a pretty simple and cheap fix that might get sold to me as something much more serious and costly?

One thing that’s frustrating as hell is that even dignosing it is a major undertaking because it’s in the ceiling- a guy can’t just pop in and look around. So they charge just to look around.

Anyway, your thoughts and ideas are welcome, just so I’m not completely clueless.

2

Doper"raindog" is an expert in HVAC installation and troubleshooting.

3

What is HVAC?

4

Heating, Ventilation, and Air Conditioning.

The best approach is to have a service contract. Since you don’t have one now, you’ll have to pay to get the unit working initially. If those repairs are a precursor to a contract you might do a little better.

5

Not that I’m an expert, but I had a similar problem last summer in the home I’m renting. Our problem was that the freon needed a recharge. Cost a few hundred bucks for diagnosis + fix. But if you want a cheaper bandaid solution, you could install a couple window A/C units.

6

Sounds to me like your thermostatic control is going toes up. Either the sending unit or the receiving unit is not working properly.

7

Could be a faulty relay. But, there’s no way anyone is going to diagnose this correctly over the internet. Just bite the bullet and get a professional to look at it.

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And by the way, adding freon is often a scam by those who don’t know what they’re doing. If freon is leaving a closed system, you’ve usually got bigger problems, or the tech is deliberately bleeding off gas so he can then “recharge” your system. If everything is operating, but the air isn’t cool enough, the first thing to check is for dirt on the fins. The OP has a functionality problem with both the heating and cooling, however, not just a diminished cooling problem.

9

Hi
It’s unlikely that the problems you experienced with the heating-----and now the cooling-----are related.

It’s also perfectly logical to look at the thermostat; although overwhelmingly it is not the problem. Overwhelmingly.

As strange as it may sound, there are really only a few components that are common to both your heating and cooling. In fact, it is a completely different “sequence of operations” (HVAC jargon) between heating and cooling.

You haven’t given us enough information to help diagnose the problem. But I feel pretty comfortable in saying that its A) It’s probably not your thermostat, and B) It’s unrelated to the heating issue.

10

When you had a heating problem, the unit was likely out on a “soft lockout.” IOW, the unit was experiencing a failure and locked itself out. The idea is, you call a technician who will diagnose (and fix) the problem.

When you switched it over to cooling, you essentially “reset” the unit. Thats why it worked when you tried it later-----it was no longer in [soft] lockout.

This is different than a hard lockout; which cant be reset and requires a technician. Hard lockouts are usually related to safety issues.

Based on the little info you’ve given us, I would guess a dirty flame sensor. Its really common. And it would cause it to work sometimes----and sometimes not.

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You really know how to get the people who work in the HVAC and automotive professions to really want to help you, don’t you.
:rolleyes:

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You know I was going top comment on the integrity issue, and I see that Rick did. I’ll bet that Rick-----an automotive expert----would likely agree that a small percentage of automotive shops are crooks----a small percentage.

And thats the case with HVAC outfits, and every industry out there. Theres bad actors in every industry.

But the vast, vast majority are decent people who are making their living honestly and competently.

But in every thread like this one I see comments that suggest that the majority are crooks. I can’t imagine how any tech would “deliberately bleeding off gas so he can then “recharge” your system.”

It has been my experience that there are too many-----for my liking anyway-----barely technically competent as well as those on the ethical fringe, in the industry. But they make up a small fraction of the whole, and no where near"rife with crooks."

YMMV.

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I would love for someone, anyone to come up with cites for an industry, any industry that does not have a small percentage of the people employed in it who are either incompetent or crooks.

And you know what? If you can’t, then STFU about how everybody in the automotive industry/dealership and all HVAC guys are crooks and don’t know their ass from third base.
[/rant mode]

14

Oh come on, sure you can. First the tech drains the system, then he recharges it, and oh by the way, he also fixes the real problem for free so he can charge for the recharge.
:rolleyes::confused::dubious: <– The SDMB doesn’t have enough of any of these to properly express the amount of sarcasm in the above comment.

15

Thanks for the information.

As for crooks, certain industries are more vulnerable than others. But there is a difference between a default presumption that the industry has a lot of crooks and that anyone I meet in the industry is likely to be such a crook. It’s my nature to trust people until they give me reason not to, I have to kind of be vigilant about NOT trusting people, otherwise I’m just volunteering to be a target.

16

On your A/C the blower moves the air around and the compressor provides the cooling. Its common for the blower to be running------and create the impression that the A/C is on------when only the fan/blower is operating.

A dirty filter could cause the compressor to cycle off on a low pressure safety. Other things could be causing it as well-----like being low on Freon.

Many, many people----hoping to save a few bucks------go and buy and install a thermostat. I can’t tell you how many times I’ve walked into a home or business and found a new thermostat installed. They’ve guessed wrong 100% of the time. (which is logical; I wouldn’t be called for the few that guessed right)

My point: resist the urge to go get a new thermostat. You might guess right; but over 95% of the time (IME) you’ll be wrong.

17

Another internet SWAG

Your filter is common to both heating and cooling and a sufficiently dirty filter will cause the unit to be hot enough to be unsafe in the heating mode (because of reduced air flow), and cause it to shut down periodically on a safety limit; and cause the compressor to cycle off in the cooling mode (because of reduced air flow).

In both cases you will get intermittent heat and cool. While there are a few things that are common to both heating and cooling (like the t-stat, and high voltage power among others), as a homeowner I’d be looking at the filter first.

18

Seriously if you call a repair person before replacing the filter you’re crazy. If that doesn’t fix it you should absolutely tell them that you were remiss in replacing the filter on a regular basis and that doing so did not resolve the issue but do what you can yourself first.

Imagine how silly you’ll feel if he replaces the filter and charges you a service call fee when he does so.

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Or angry, because she thinks it would make the tech a dirty crook!