Help me diagnose an HVAC problem

[trader_4]

You could call the owner, tell them to set it to heat, turn the temp way up and see if the furnace/blower come on. If so, then you have power to the inside unit. Outside compressor will be on a separate breaker. They have an access cover, you could look for 24V on the low voltage wires to the contactor, but be careful, you have 240V nearby.

One thing not mentioned was a float switch in the new setup, so I take that to mean there isn't one. I suppose there could have been one in the old pan and whoever replaced it disconnected it and left it open. That would certainly keep it from running. I think it's probably wired in series with the thermostat wires, not on separate wiring. Who did this work? If it was an HVAC pro, 99% they would have tested it running. If it's some handyman type, they might not have.

Beyond that, it's a matter of tracing wires and checking for voltage. Should be

24V between the cooling call wire and common at the unit. Cooling is typically yellow. That's what it takes to get the blower running and then there should be 24V on the wires going to the contactor/relay on the outside unit.

[Ralph Mowery]

In the US green has meant to go if at a traffic light, start machinery or turn on lights for hard telling how many years. Red means stop or off. I am just over 70 and that is the way things were in the US

Where I worked that was the way things were, then in the 1990's we got in some new electrical equipment from Europe that red meant 'danger the power is on' and green meant no power and it was safe. Lucky no one was killed by that shit.

[TimR]

I had assumed there would be a float switch. There is not, and there was not one in the old pan, I asked. But that was my first guess, that someone had left the float switch open.

There was no pro doing this work. There was some kind of acquaintance skinny enough to get through the small hatch who replaced the pan. Weirdly, he glued the PVC drain pipe into the new pan. But here's my problem. I don't want to walk away from a half solved problem with someone so short of money, but I also don't want to chase this thing forever. The pan we're talking about is underneath the unit. It's an overflow pan, not the primary condensate pan. Why did it ever rust, why did it ever have water in it? It should not. So, either the primary pan has rusted through, or the primary drain pipe is clogged. There are no cleanouts or vents, so it looks like I'm cutting a pipe and trying to get a brush or snake through it. I would guess they usually clog at the trap, which by the way is very shallow. Is that correct for residential? It would never work in commercial, the negative pressure would suck all the water back. Anyway, if the primary pan is not draining, then the overflow pan will work until it clogs, and then the ceiling will come down again.

If I understand code, you're supposed to either put in a float switch or you must route the overflow drain where the homeowner will see it, but I haven't found where either drain dumps.

If I cut the PVC, is there a no-hub in that size? There's no pressure on these lines, and pretty sure it will need to be unclogged again.

[invalid unparseable]

The meaning of "Green" means safe. The meaning of "Red" means danger. That's why in traffic lights "Green" means go, "Red" means stop.

So in machinery, the Red (danger) button should mean ON (it is dangerous to press this button; think carefully before you press this button), and the Green (safe) button should mean OFF.

[Ed P]

That would be asinine. Green go, red stop, why would you try to change that? You already said that.

[rbowman]

That has never been the case and is ass end backwards to the way most normal people think.

The large red button means STOP.

[invalid unparseable]

The nuclear button on the US president's desk (also Kim Jong-Un's) is RED. Ask Trump. The top thinkers used the colour code correctly like me.

[invalid unparseable]

It's time for change - Obama.

[invalid unparseable]

You need to adjust. The world has gone metric and you are still stuck with the imperial system that even the imperial Brits who invented it have forsaken. Get with the programme. Pull yourself from under your rock. Be a modern man.

[bud--]

That is pretty funny. There is no plug. Nothing was "tripped". The switch is a "disconnect" used to safely work on the unit, like putting in a pan. Circuit breaker off would be close.

[micky]

I'm not sure red and green are part of the metric system, but I am sure that if you ever try to use machinery in America, you should be careful.

[invalid unparseable]

The link below is a remote control of some heavy machinery. The ON button is using the red colour correctly. If you think of red traffic light and red ON button as "DANGER" and the green traffic light and green OFF button as "SAFE", then there will be no confusion.

[invalid unparseable]

Here is another example of correctly using red for ON button:

[Ed Pawlowski]

The remote you show is STUPID. The world has used red for stop forever so trying to change that now is impossible around the world. Talk about introducing danger to the workplace.

Sorry, but your one man campaign is doomed. Common sense prevails. You should have started 100 years ago.

There is NO confusion

[micky]

You commented on the imperial system....

so I was commenting on the *metric* system.

[Cindy Hamilton]

To paraphrase a famous move from 1974:

Forget it, man. It's Usenet.

[Dean Hoffman]

It's no wonder the British Empire collapsed. Inefficiency. "Programme" vs. "program"

[invalid unparseable]

The original word came from Greek, Latin, and French (the route of Roman conquest of the British Isles).

The early American population were mostly illiterate cowpokes. Later generation learned how to spell, and spelled the words as they heard them. That's why "programme" became "program", and all "u" in "colour", "neighbour", "mould", ... have all disappeared.

programme (United States program) n    noun

1    a planned series of events. Ø a set of related measures or activities with a long-term aim. 2    a sheet or booklet detailing items or performers at an event. 3    a radio or television broadcast. 4    (program) a series of coded software instructions to control the operation of a computer or other machine. n    verb (programmes or programs, programming, programmed; United States programs, programing, programed) 1    (program) provide (a computer or other machine) with a program. Øinput (instructions) into a computer or other machine. 2    cause to behave in a predetermined way. 3    arrange according to a plan or schedule. Ø plan; schedule.

PHRASES     get with the program North American informal become aware of the realities of a situation.

DERIVATIVES     programmability noun     programmable adjective     programmer noun

ORIGIN     C17: via late Latin from Greek programma, from prographein 'write publicly', from pro 'before' + graphein 'write'.

[trader_4]

Agree with that reasoning. You could take some water up there, pour it in the overflow pan and see if it drains. Should also show up outside somewhere, if that;s where it drains. If the furnace part is high efficiency, where does the condensate drain for that get plumbed in? That water has to go somewhere too. They must have Fernco couplings for the 3/4" or whatever PVC pipe size. If you use one of those, then there will be a future cleanout.

[TimR]

Going back Friday to do what you suggest. These are minimum wage people who can't miss a shift before their day off. The weather is cool all week, hopefully not too much water in the pan before then. I didn't think of weedwacker line, that's a good idea. Of course when I cut the drain line to the internal pan, I have to catch all it's holding, if any.

Obviously there's no point in a trap on the overflow pan. I'm not sure the tiny trap in condensate pan does anything. But should a vent be added? I hate to add any additional tasks but could glue up a tee and vent before I go.