A/C Pros in Highlands Ranch area?

So, here’s the update. Had a guy come out who has done some work for us in the past (new water heater, some plumbing work) that we’ve been happy with. Ran through what I had found based on the advice here. He smiled and nodded his head and said “nice . . . that helps to know and probably saves some time.”

Transformer was for sure fried, so he said he likes to go with simple and works his way up from there. He grabbed a new transformer with an inline fuse . . . and it killed 2 fuses in a row. So . . . there’s a short “somewhere”. He narrowed it down to a short someplace on the wiring from the thermostat on the main floor down to the furnace. Problem is, we have a finished basement so a lot of that wiring is hidden god-knows-where. That thermostat has been in place for 10+ years, but he said the short wasn’t where he could see it and it could be pretty much anywhere. Said that wiring is not often very carefully put in place and it can rub on metal/pipes/etc and eventually short. The house is 20+ years old so it could have just hit that point on whatever weak spot it had.

He suspects it may have been a wire for a humidifier we don’t use. His concern was whether or not there were enough good wires to still use the old thermostat and have it work. If not, then he said it would be down to either trying to use a thermostat that ran on fewer wires, or if still shorting then run a new wire down (not fun) or just switch to a wireless thermostat—which the only one he had was $$$ and he said he’d rather not go there just yet unless he ran out of options. He ended up getting it wired back up and working with the old thermostat!!! At least for now, LOL. He said he had no way of guaranteeing that there wasn’t another short in the remaining wires that could go anytime—but said that, if it were him, he’d just let it run and call him if there’s another problem and worry about it then.

He told me the control board I had was notoriously bulletproof and that pretty much the only ones he’s ever replaced were from being submerged. So I guess that’s good to hear.
$260 all in to get up and running again. I may look for a good wireless thermostat just to keep on hand in case of emergency down the road to hedge my bets.

FWIW I'm in the process of installing a heat pump; it's arrived, still looking for a contractor to do the install. Part of that involved upgrading our thermostat to eek out the most performance. Lot's of hype in that market! Nest, Ecobee, blah, blah, blah. Wasted a lot of time sorting all that out.

Ended up going with a Honeywell Prestige IAQ system with Redlink and internet. What might interest you is it only requires 2 wires for the thermostat, all the rest is in a box by the HVAC. Plus all the reviews are pretty much stellar.

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Originally Posted by Ramsker

So, here’s the update. Had a guy come out who has done some work for us in the past (new water heater, some plumbing work) that we’ve been happy with. Ran through what I had found based on the advice here. He smiled and nodded his head and said “nice . . . that helps to know and probably saves some time.”

Transformer was for sure fried, so he said he likes to go with simple and works his way up from there. He grabbed a new transformer with an inline fuse . . . and it killed 2 fuses in a row. So . . . there’s a short “somewhere”. He narrowed it down to a short someplace on the wiring from the thermostat on the main floor down to the furnace. Problem is, we have a finished basement so a lot of that wiring is hidden god-knows-where. That thermostat has been in place for 10+ years, but he said the short wasn’t where he could see it and it could be pretty much anywhere. Said that wiring is not often very carefully put in place and it can rub on metal/pipes/etc and eventually short. The house is 20+ years old so it could have just hit that point on whatever weak spot it had.

He suspects it may have been a wire for a humidifier we don’t use. His concern was whether or not there were enough good wires to still use the old thermostat and have it work. If not, then he said it would be down to either trying to use a thermostat that ran on fewer wires, or if still shorting then run a new wire down (not fun) or just switch to a wireless thermostat—which the only one he had was $$$ and he said he’d rather not go there just yet unless he ran out of options. He ended up getting it wired back up and working with the old thermostat!!! At least for now, LOL. He said he had no way of guaranteeing that there wasn’t another short in the remaining wires that could go anytime—but said that, if it were him, he’d just let it run and call him if there’s another problem and worry about it then.

He told me the control board I had was notoriously bulletproof and that pretty much the only ones he’s ever replaced were from being submerged. So I guess that’s good to hear.
$260 all in to get up and running again. I may look for a good wireless thermostat just to keep on hand in case of emergency down the road to hedge my bets.

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I've dealt with many many shorts in low voltage.. I've never been able to NOT find them and/or isolate them and KNOW which wire is shorted either. Does your buddy have a multi-meter? Does he truly know electrical or just enough to get dangerous?

The only reason I ask is because in 14 years I've only had maybe 3-4 shorts in thermostat wiring going up through the walls to the thermostat. Not saying it doesn't happen, and you may have that issue but it's not exactly common.

I have however, had lots and lots of bad contactors cause this exact issue. He needs to either find the short with his meter to ground and/or isolate the AC low voltage circuit from the furnace low voltage.

Let me know what he finds.. Its kinda rare to have a true short in that wiring.

Ive seen a fair amount of shorts in the stat wire, but I work in the commercial field and people are always moving wiring around. Most common place for the short is right where the brown shielding it, people strip it off with strippers and cut through all the wires without realizing it causing a short between the wires.(hack install there is a right way and wrong way). But I agree never been able not to tell which wires are shorted, just a basic meter use. As far as thermostats my opinion is only Honeywell of a good quality, everything else is a gimmick. Maybe a Jci both are proven control makers, just no one stocks Jci thermostats.

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Originally Posted by bryjcom

I've dealt with many many shorts in low voltage.. I've never been able to NOT find them and/or isolate them and KNOW which wire is shorted either. Does your buddy have a multi-meter? Does he truly know electrical or just enough to get dangerous?

The only reason I ask is because in 14 years I've only had maybe 3-4 shorts in thermostat wiring going up through the walls to the thermostat. Not saying it doesn't happen, and you may have that issue but it's not exactly common.

I have however, had lots and lots of bad contactors cause this exact issue. He needs to either find the short with his meter to ground and/or isolate the AC low voltage circuit from the furnace low voltage.

Let me know what he finds.. Its kinda rare to have a true short in that wiring.

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He had a multi-meter. He's the owner of the company and they've been around awhile and seem to have a good rep . . . so I assume he knows what he's doing. It could be that my description of everything is more the problem in my word choice or order and since I'm not great at electrical and don't know that side or HVAC all that well. "Suspects" was maybe a poor word choice on my part. The short that was frying the transformer was in the wire he eliminated from what he was saying and when that was taken out of the equation everything was then working and not blowing the fuse. What he was saying was that he couldn't see or be sure where that short occurred in the line because it wasn't where it was visible . . . and that if there was a spot that somehow rubbed through to short that wire, that it could rub through another of the wires somewhere down the road and short there instead (or it may never happen or it could have been a nicked wire to begin with that finally made contact, etc). I'm assuming he checked other things while he was down there to see if there were any other obvious sources of a short but I wasn't watching him and probably wouldn't really know what I was looking at anyway.

I mean . . . I can only go on what I know (which is not much, but trying to learn) and what he's telling me and advising on what he'd do if it were his house.

When you say "bad contactors"--what would examples of that be? Is that just connectors on the board? I'm pretty remedial with electric and HVAC so I'm trying to get a better understanding of it all.

What he found is completely possible, I would just want to know exactly which wire in the bundle is doing it, but I’m pretty demanding if the people that work under me. And in a house it’s almost impossible to pull a new wire so a wireless is about the only option. THte contactor I’m referring to is on the condensing unit. It is kind of like a relay. It uses 24v on that one for the coil and pulls the contacts in to start the compressor and fan

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Originally Posted by fitterjohn

What he found is completely possible, I would just want to know exactly which wire in the bundle is doing it, but I’m pretty demanding if the people that work under me. And in a house it’s almost impossible to pull a new wire so a wireless is about the only option. THte contactor I’m referring to is on the condensing unit. It is kind of like a relay. It uses 24v on that one for the coil and pulls the contacts in to start the compressor and fan

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He actually said that it's fairly common (or maybe even most common?) for a shorting issue to be outside, so that matches with some other stuff he mentioned. He took a look out there and it seemed to all check out.

I really appreciate all the help and feedback here from everyone. I'm not the world's most handy guy, but I try to DIY stuff where I can and to learn along with way with repairs and home improvement . . . so it helps to put some additional pieces together along the way.

Here's a question on pulling a new wire.
The basement is finished, but it has a wood floor and a crawlspace underneath. The thermostat is pretty much above/near a little utility room in the basement (access panel for sump pump and crawlspace and a water softener). The furnace is on the other side of the basement, but the crawlspace is good sized and runs all the way over there. Could new thermostat wiring be run down under that floor and across/up to the furnace? Or does it need to be in/across the ceiling?

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Originally Posted by Ramsker

He actually said that it's fairly common (or maybe even most common?) for a shorting issue to be outside, so that matches with some other stuff he mentioned. He took a look out there and it seemed to all check out.

I really appreciate all the help and feedback here from everyone. I'm not the world's most handy guy, but I try to DIY stuff where I can and to learn along with way with repairs and home improvement . . . so it helps to put some additional pieces together along the way.

Here's a question on pulling a new wire.
The basement is finished, but it has a wood floor and a crawlspace underneath. The thermostat is pretty much above/near a little utility room in the basement (access panel for sump pump and crawlspace and a water softener). The furnace is on the other side of the basement, but the crawlspace is good sized and runs all the way over there. Could new thermostat wiring be run down under that floor and across/up to the furnace? Or does it need to be in/across the ceiling?

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Tape new wire to old and pull...............

I do what kazoo said but some a-hole always puts a staple in to hold it and keep that from happening. You can run a new wire any way you can get get it from a to b.

You can run the new wire around without much issue.

With finished basements you have the original tract installer and likely a different lowest bidder doing the basement finish. No telling where the wire is shorted. I've run several Stat runs because of suspected sheet rock screw hits years after the fact.

The reason there's such kickback about the diagnosis is that it's pretty easy to find out which wires are shorting though. Like less than 5 minutes with a multimeter would tell you which pairs or more have continuity.