Hi,

I just bought this house and did not realize that the Central Air/Heat wiring were all disconnected. The handyman want it $500 to wire this. I see no point of spending this type of money just for connect these wire.
I hope someone here can help me on these connections. I don't know much about them, but am willing to try. Thanks


About this system:
It's a 2 Zone, upstair and 1st floor. 2 A/C compressor outside, 2 blower - 1 upstair and 1 on 1st floor. 1 gas boiler which sends hot water via pipe to 1st and 2nd floor when called. Then, a heat exchanger blows the hot air out. The 2nd floor's wiring is connected and it works. The problem is only on the 1st floor.

The thermostat is a Honeywell T8600, one of the older model, the 5 Wire is not connected to this thermostat at all.

This is how the wire is from the Blower.
A Thermo Delay box's white wire is connect to the blower boards C.
The A/C compressor Red connected to C and white connected to Y.

3 wires coming out from the board of the Blower ( I guess this is to connect to the Tstat)
Red wire connected to R.
White wire connected to Y.
Green wire connected to G.

2 wires a RED and a White coming from the boiler and it's not connected to the blower. I think this should be connected to the Tstat.

I can get the AC to work OK. It's the Thermo Relay (I think this is the unit that set the blower to continue to blow until the heat temp drop's below a set temp. This will keep hot air blowing intil the water cools down and saving some energy. At least that what the installer said) and the 2 wires white and red coming from the boiler that I have problem understanding.

The thermo delay wires white and red, but only the white get connected to the blower board's C terminal. What is the C terminal? The thermo delay connects to it and also the AC compressor is connected to C. Why, one is from heat and one is from the AC?

The red and white wire coming from the Boiler. Should this be connected to the blower terminals or straight to the Thermostat?


Thanks in advance for any help this board can provide

Frankie

NY

If you had a lawyer at the closing, talk to him. You may be able to let the handy man, or better yet, a qualified heating technician do the work, and send the bill to the seller. Might check here for legal advice too.

Otherwise.

Usually there is a 24 volt AC transformer in the furnace with the secondary winding connected to a red wire running to the thermostat and a blue wire, common, to the gas valve, A/C relay, and fan relay. From the thermostat there will be white wire to the gas valve, yellow to the A/C, and green to the fan. The thermostat is wired to switch the power from the red to the white, yellow, and green as needed with the blue completing the circuit. Most thermostats and furnaces have the contacts labeled R, B or C, W, Y, and G for the corresponding wire colors. It may be wired to have the A/C control wires return to the furnace and its controls and then a second wire goes to the A/C unit. Internal wiring may replace the green wire if the thermostat does not give you the option of fan only or continuous fan. Digital or programmable thermostats may need the blue wire connected to them.

A 2 zone system may be more complicated as each zone has to wake up the boiler. I am out of time, right now, but may be able to give more details tonight.

Thanks labman, I'll wait to hear from you later. I tried contacting the lawyer and the seller had moved out of the country. It's very hard to get the money back now. Thanks

I hate people that make a mess like that and then disappear. You should be able to figure out some of your answers from that paragraph I posted this morning. Leave the A/C wiring alone, it is working and any old pair of wires running from the Y and B or C will work.

For a 2 zone system to work, you need 2 thermostats, 2 zone valves, maybe 2 relays, and a bunch of wire. Much of what I know about about zone valves, I learned last winter on the White Rogers web site on their trouble shooting page. The thermostat needs to open the zone valve, fire the boiler, and in your case start the blower. Perhaps the blowers replace the valves, water always circulates when the boiler is on, but only heats the room when the thermostat connects the R terminal to the W one. From there, the white wire needs to connect to the gas valve, pump relay, zone valve if any, and the correct blower. All of those need to also have a connection, B or C to the other terminal of the transformer to complete the circuit. I am not able to figure out what some of the connections you listed do. Since the second floor system works, you might try wiring the first floor the same as it if all the components are the same. You are correct that blowers usually run after the heat is off, controlled by a timer or temperature switch.

The W-R zone valves I worked on need a double throw relay controlled by the white wire to switch the red wire back and forth between open and close. When ''open has power, it also sends power to the W terminal of the boiler.

Sort through things and get back to me tomorrow night if you can. I think $500 to wire it up is outrageous. I would love to come do it for $50. It may take a couple of days, but we will work this out.

OK, Here's what I test out so far. Everything works, but the HEAT fan keeps blowing for a long time before it's turns off and it's blowing out cold air at the end. The THERMO FAN RELAY might be the problem since it's not hook up. Please read below for detail:

HEAT,I got the R and W wire from the boiler hook up straight to the TSTAT's R and W terminal and tested it OK.

A/C, With boiler wire still hooked up. I got the W, G and R wire hooked up to the TSTAT's Y, G and Rc and test it the A/C and it works OK.

The heat's fan kept blowing when the boiler had stop firing and it was blowing out cold air. Does this has the do with the wire from the THEMO FAN DELAY not connect it? I wasn't sure where to connect this wire. The W wire is hook up from the Relay to the blower's C terminal and the red wire is cut off and no connect to anything.


Thansks

Frankie

The blower controls are one of the most difficult parts of a HVAC system, needing to come on after the air is heated and stay on for a while after the fuel is shut off. In some cases, the blower has multiple speeds for cooling and different rates of heating. Likely the disconnected heat delay switch is the cause of the problem. Does the up stairs blower work properly? If so, try to duplicate its connections downstairs. I am too confused about how the system works to help more for now. I have never worked with a hot water system that had blowers. You need to answer a few questions. Does the system have have valves actuated by the controls? Do you have separate thermostats for up an down stairs? For the parts to work independently, you must have 2 thermostats. Can you find information on the system on Amanda's web page? If so, post the links.

The 5 wire cables are easy to connect up on the more complicated systems. The red, white, and green are adequate for heat and fan only systems. They are also fine to run out to the coil of an A/C unit or other remote component. If there is a convention for connecting them, I don't know it.

Whoever disconnected things, had a reason. It could be that the delay switch wasn't working or something.

Hi labman,

Thanks for your help so far and here are some question that I can answer.

Does the up stairs blower work properly? YES.

Does the system have have valves actuated by the controls? Don't Know.

Do you have separate thermostats for up an down stairs? Yes, separate thermostats.


My A/C system is Amana, 2 compressor, 2 air handler/blower for each floor. Then the Heat is a single gas Burham boiler that has copper piping that runs to the 1st and 2nd floor. Each air handler has a heat exchanger that will blow hot air through the radiator/fins. Hope this helps.

At this point, see if wiring the downstairs blower delay switch like the upstairs one that is working, gets it working too. If not check the switch itself to see if it is still closed when the blower should have shut off.

Your system may not have zone valves. Even if it does, they shouldn't have anything to do with the blower continuing to run.

Quote:

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Originally Posted by labman

At this point, see if wiring the downstairs blower delay switch like the upstairs one that is working, gets it working too. If not check the switch itself to see if it is still closed when the blower should have shut off.

Your system may not have zone valves. Even if it does, they shouldn't have anything to do with the blower continuing to run.

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... you should check at what temperature the fan come on.. and shut off.. (aquastat)