How to make sense of the choices? Thread split off.

[RoBoTeq]

I tell people I power it off the unit to save them buying and replacing batteries. They like that

And that can be a good thing, right after they sign a pm agreement. Otherwise, you had a one shot customer instead of a customer for life, along with another asset for your company to make it worth more.

[syndicated]

Interesting that you think I am frustrating for giving you ways to increase your livelyhood. If your company sells annual pm's, as it should, then there is no way the batteries would ever have time to go bad. If your company is not selling pm's, your boss doesn't own a business, he owns a job.

For HVAC companies to stay in business and progress, they must build an annual customer base. Having a customer who you have installed a system for, but who did not see the value in buying an annual pm agreement, changing a t-stat battery is a very good way to keep that customer as a customer.

I am really sorry if my giving you sound advice for keeping customers frustrates you. May I suggest you just ignore me?

*sigh*
See, the thing is, I didn't ask you for business or career advice, and seeing as we're the largest Lennox dealer in Canada, I think our business model works just fine.
Changing batteries is not part of our PM list, it's the customer's responsibility because its their equipment, and they're adults.
Going to a no heat call for dead batteries is not a profitable venture, and generally gets people angry, on both sides. That's why we hook up the C terminal.

You are frustrating because you *think* you're right. All the time. To the exclusion of everyone else. The manner in which you express your disdain and impatience with others on this site who aren't blue blooded republicans is why me and others find you irritating.

[RoBoTeq]

*sigh*
See, the thing is, I didn't ask you for business or career advice, and seeing as we're the largest Lennox dealer in Canada, I think our business model works just fine.
Changing batteries is not part of our PM list, it's the customer's responsibility because its their equipment, and they're adults.
Going to a no heat call for dead batteries is not a profitable venture, and generally gets people angry, on both sides. That's why we hook up the C terminal.

You are frustrating because you *think* you're right. All the time. To the exclusion of everyone else. The manner in which you express your disdain and impatience with others on this site who aren't blue blooded republicans is why me and others find you irritating.

Wow! Me, a blue blooded Republican? That's news to me. If I thought it would do any good, I'd be backing the goofballs in the Libertarian Party. They think more like I do.

But we digress. As long as your company is doing pms and building clientel, I can't argue with your particular business plan. I am not one to believe that any one plan is the best for everyone, and do express that while some fundamentals should be adhered to, diversity can make your company stand out.

And in no way do I ever think I am right all of the time. If I were right all of the time, I wouldn't come to places like this to learn. I do however believe in giving back to the forum from my expertise as I gain knowledge from the expertise of others.

So, you take the high road and I'll take the low road and we will most likely meet at the same place at the same time with a few different tales about our journeys.

[54regcab]

Ok maybe a stupid question here, but why would anyone sell or even buy "today" a stat that is dependent on the system transformer to power it? that is really old school. I sell the Honeywell 5000....6000 and all of them use batteries, stat never goes blank, well unless the batteries run down.

The thermostats we install as part of our project have Zigbee radios in them. The Zigbee radio would drain the batteries too fast if the thermostat wasn't 24V powered. Sure they could have designed the thermostat differently so that only the Zigbee would drop if the 24V was gone, but vendor selection for the thermostat is above my pay grade.

[54regcab]

I have already mentioned it once, if you don't want the stat to cut out during an open limit on that particular board, wire it to the red on the secondary side of the transformer on the primary side of the limits, there is no danger since the gas valve is protected by a high limit, jeeeezzz! how simple!

In a previous post you suggested a wiring up relay to control this. Not quite understanding you on this post, are you saying just let the secondary limit for the gas valve take care of it, no relay required?

[54regcab]

I got that. Which Carrier model? This does not seem to be a very popular board.

This series is popular in our area, I'm not sure how popular it is on a national basis. I've seen it installed in Carrier, Bryant, and Payne versions.
http://www.sbeelectricandhvac.com/do...-310aav-error/

[RoBoTeq]

This series is popular in our area, I'm not sure how popular it is on a national basis. I've seen it installed in Carrier, Bryant, and Payne versions.
http://www.sbeelectricandhvac.com/do...-310aav-error/

I ask you for a model number of what you are claiming is a very common furnace in your area and you post a link to some consumer site?

From the troubleshooting guide in the installation manual for that model furnace, this is the most probable solution to your thermostat problems;

The thermostat is not compatible with the

furnace control. Either install a ballast resistor,

connect the Com24V thermostat terminal to

the thermostat, or replace the thermostat.

I don't see anything on the actual wiring diagram (not just the internal schematic you posted) that indicates that when the limit switch is open, it disconnects power to the R terminal to the thermostat.

Why did you not post the entire wiring diagram?

Here is the manual; http://www.alpinehomeair.com/related...structions.pdf

[54regcab]

The site I linked to had the same diagram that you linked to. They must have pulled the download link, because it's not there anymore. That's where I got page 27 of the manual, the link you provided will show the same wiring diagram.

At first we thought we had a compatibility issue, then we investigated further. We found after 5-10 minutes of running, the thermostat would go blank and the furnace gives the 33 limit fault code. We verified no power to thermostat backplate after it cuts out on limit. Discharge air coming from nearby registers normally hits about 130 according to out IR thermometers right before the thermostat goes blank. We've seen the same thing on several different houses, so it's not an isolated case. There are other furnaces that do the same thing, but not nearly as common as this particular line.

[beenthere]

I ask you for a model number of what you are claiming is a very common furnace in your area and you post a link to some consumer site?

From the troubleshooting guide in the installation manual for that model furnace, this is the most probable solution to your thermostat problems;
I don't see anything on the actual wiring diagram (not just the internal schematic you posted) that indicates that when the limit switch is open, it disconnects power to the R terminal to the thermostat.

Why did you not post the entire wiring diagram?

Here is the manual; http://www.alpinehomeair.com/related...structions.pdf[/SIZE][/FONT][/SIZE][/FONT]

Fig 39 shows the limits/safeties are before the R terminal, and kills voltage to it on an open limit, draft safe guard switch, or roll out or blocked vent witch if one is installed.

[54regcab]

I don't see anything on the actual wiring diagram (not just the internal schematic you posted) that indicates that when the limit switch is open, it disconnects power to the R terminal to the thermostat.

It does appear that the wiring diagram in the link you provided is slightly different. However, I'm still not seeing how the power path isn't broken when LS1 opens.

[RoBoTeq]

Fig 39 shows the limits/safeties are before the R terminal, and kills voltage to it on an open limit, draft safe guard switch, or roll out or blocked vent witch if one is installed.

Look at the wiring diagram of fig. 39 closer. That circuit is between pins 6 and 8 on connector plug 1. That is all the schematic shows. The transformer hot lead does not go to that same plug, but rather directly to the SEC1 terminal for the printed circuit board. Notice that the CPU is energized by the transformer even before the fuseable link, and that the R terminal also has a wire from the CPU.

I am just having a difficult time believing that Carrier/Bryant/ICP furnaces kill all thermostats without battery backup when ever there is a power failure.

[RoBoTeq]

It does appear that the wiring diagram in the link you provided is slightly different. However, I'm still not seeing how the power path isn't broken when LS1 opens.

Do you not see the wires going to and from the CPU from the transformer and the R terminal?

[beenthere]

Do you not see the wires going to and from the CPU from the transformer and the R terminal?

Look at it again. There is no other connection from the safeties to any other device that would shut the furnace down.