HVAC Controls 1

[BlueToad2222]

I'm at 1:39 and already wshing you weren't so boring.... whats with the delays in speech, repeating yourself and stating the obvious?? I mean you are smart but you just go too slow for me to want to learn anything from you also you should explain what some of that stuff does... like the reversing valve I hear you talking about right now... what does reversing vlave do? these are just some of the problems that prevent you from being a HVAC Guru on YouTube

[DrZarkloff]

@BlueToad2222 Not everyone is so fluent with English. Besides, my brain doesn't work in overdrive very well.

[TheControlsFreak]

@BlueToad2222 FYI... A reversing valve is a solenoid valve that is found in Heat Pump units. Essentially a heat pump is just like a regular A/C in your house except when it comes to heating. The reversing valve makes the refrigerant cycle run the other direction so that the air coming off the top of the condensing unit outside is COLD and the air blowing across the coil on the inside of the house is HOT. --- Reversing Valve. More HVAC Controls information at TheControlsFreak Blog.

[BlueToad2222]

I'm at 1:39 and already wshing you weren't so boring.... whats with the delays in speech, repeating yourself and stating the obvious?? I mean you are smart but you just go too slow for me to want to learn anything from you

[Alxscode]

I like the elephant you drew when you made R to G.

[DrZarkloff]

@Alxscode Thanks. lol

[easyhec]

Hi, my heater only works with "on' and not "auto". If there are only four wires on my therm (R,W,Y,G) why doesnt the thermostat call on W and G (heat and fan) with auto. my first thought was the "on" function is directly closing circuits without use of relay in the thermostat. So maybe heat relay in thermostat is bad. So i replaced thermostat. But no change. I can hear the relay snapping close during auto setting of temps. Is there another factor keeping the "auto" circuit open?

[DrZarkloff]

@easyhec What kind of thermostat do you have? Some thermostats will only send a W signal to the equipment. It's then up to the equipment to energise the fan relay. Some thermostats have a switch. Remove the front cover from the thermostat and see if there's a switch that you can flip between gas and electric. Make sure that switch is in the proper selection. It sounds like you probably have a heat pump or straight cool system. You'll want to select electric if that's the case.

[natascore]

how about a miniture refrigerator with no fan(the kind if frig you find in a hotel room)it just stop working i hear nothing i would like to check the ptc relay and thermo..any help?"

[natascore]

@natascore and your videos on this subject are the best i've found on youtube(Impressed)

[DrZarkloff]

@natascore Is the compressor running? The hot gas line should be hot and the suction line going back into the compresssor should be cold.

[natascore]

@DrZarkloff no nothing is hot or cold,i t comes on just for a moment when i first plug it in,and i got it to turn on a couple times by turning the temp adjusting knob but always just for a moment then never comes back on,it doesn't come on every time i plug it in,but more often then adjusting knob..thanks for the reply

[justtimp]

I have been watch you videos and you have corrected alot of my own methods of HVAC systems thank you

[DrZarkloff]

@justtimp Thanks for watching.

[ranjit3o]

..Hello Sir THis is 2nd time i,m sending you Comments And Msg too Plss reply me, i,m impress with this video. i hv quetions.. How Long it take to become a HVAC technician(Short to Short) And What is total cost for the Study? plss pls Help me I want to Start my Carrier.. Pls reply me on my on y4h00 vartia_r thanx

[DrZarkloff]

@ranjit3o There are 2 year HVAC schools at many community colleges. The price can vary.

[ranjit3o]

Hello Sir i,m impress with this video. i hv quetions.. How Long it take to become a HVAC technician(Short to Short) And What is total cost for the Study? plss pls Help me I want to Start my Carrier.. Pls reply me on my on y4h00 vartia_r thanx

[jevianfe]

great vidoes Dr Zarloff. greetings from the Northern Virginia Community College Hvac program.

[raptorman120]

you know.....While i was watching this i had a GREAT idea. why dont you Go teach HVAC at a trade school?! you would be Perfect. i mean you have to enjoy Making these videos that each thousands of us about HVAC right? i'm just throwing that out there lol

[DrZarkloff]

Thanks for your vote of confidence. I enjoy my job as a tech for the school board.

[lubime10]

Very gooooood Dr. Z

Thank you very much.

[DrZarkloff]

Thank you for watching.

[ng123abc]

DrZ: thanks for all your great and easy-to-follow info. I'm a single mom do-it-myselfer. My unit's blower has been running 24/7 since I turned on AC ths yr. I've learned & worked through - have definately narrow problem to the control board, ...but what's next? Since all functions works as should except fan won't shut off, ...do I need to replace entire board or ...is there something else?..like what is a wire relay? Thanks SO much for any help you might provide!

[DrZarkloff]

If the blower relay is integrated in the board then you really don't have much of a choice but to replace it.

[johnbvanveen]

Hi Dr. Zarkloff

Please tell me my next course of action.

HVAC cools very well. However, when the system is turned off, the indoor blower and power ventor blower come on for a few minutes every half hour or so.

When the thermostat is disconnected, a jumper wire is connected to both terminals of the upper limit switch (120F), and the air pressure gauge is disconnected, it still happens.

What do you think?

Sincerely

[DrZarkloff]

It sounds like the thermostat is set for the fan to circulate. The fan relay in the air handler will usually keep the fan running for a couple of minutes after the system has satisfied.

[johnbvanveen]

thank you Dr. Zarkloff

sincerely

John Van Veen

[bignlng9]

Depending on the type system and board, if the limit is jumped, that signals the board that a high temperature condition exists, so it will run the blower to cool the furnace down.

[johnbvanveen]

test

[Asfxiate]

Nicely done,

One question, on the board that I am currently looking at, it has both the GH and GL, which I'm positive is High and Low settings for the fan, however I can only connect one, because I only have one the wire for fan, BUT I can only go with GL or the HVAC unit will not turn on, showing there's an Error. Can I somehow manage to get around this?

It's a GE zoneline, if that may help.

[DrZarkloff]

I know that Friedrich PTAC units have a feature that allows you to connect a remote thermostat to it rather than using the onboard controls. The terminal strip to the remote thermostat give you the option to use either GL or GH. I'd use GH just to be on the safe side.

[richiemabie]

Don't forget about McQuay!

Respectfully

[DrZarkloff]

Thanks. Amana, too.

[hvacrdude1]

HvacrTalk . com , Welcomes Techs, to join , for free, all you need is a valid email address for activation .

[coollikthat31]

how can u troubleshoot a control board to see if it bad or not thank u dr.z

[1Ronin187]

DrZ

I'm a newly grad from heat and air school. I have a question for you. I have a heat pump w/ aux heat (gas). However, the thermostat in the house does not have the emergency switch option. It can only switch to HEAT and COOL mode. There is no way to get the second stage heat to come on. I believe the WRONG thermostat was installed. Can you help PLEASE? Oh, the resident said the heat will for a while then it went cold. Is defrost board bad Dr.? Thanks

[DrZarkloff]

Take a look at the base plate at the thermostat. See if you have an "E" terminal. If you do then connect a jumper wire between "E" and "W2". See if that helps.

[1Ronin187]

Thank you for taking your time to respond DrZ.

[thesixtiesguy]

isn't it just easier and more correct to replace the t'stat with a HP type?

[Hungry2Play]

hey DrZ can u help me out? In school i learned how to fix ACs with Control switched but i didnt learn how to fix the electronic controls can u help me out and explain what each and every thing on a control board does? If u can

[DrZarkloff]

I'll try but there are so many different types.

[Hungry2Play]

well if there is 1 type that is most commonly used i think that'll be best if u made a video on that, or just any kind i just need a description or an explanation of some controls on it

[napais]

Hello Dr. I have a question in the property where I work, we do not have gas furnance , we only have units on the roof or outside at patio, we can get cooling and heating from this condenser units outside. In this kind of set up can we say that we heat pump????

[thesixtiesguy]

Package rooftop units most often use gas heat. see if there is a gas line attached.

[hot2wheeler]

that sounds exactly like a heat pump

[GoldRushDutch]

Nice schematic. Honeywell T7350H is phenomonal. 4 stages of heat and 2 of cool. Humidity sensor cycles unit at a more effective rate.

[BLSzepCFH]

do you ever work on furnaces? probably not that much considering you live in florida right?

[DrZarkloff]

I don't work on very many gas furnaces. I mainly work on refrigeration, air conditioning and heat pumps.

[napais]

I was pausing,and play to take notes in this nice video.

today since I am rocky saw that superv and me in trouble call, he replaced an old tstat with dial and mercury inside to a manual modern version, but he did not connect the blue wire to anything even the blue was @ oldtst

red= 24v

blue= common 24v why we need 24 common volts what it is the use of it.

green= fan blower motor fan

yellow= 1st stage cooling = compresor

white= 1 stage heat

O= reversing valve cooling

B= heat pump in heat

[DrZarkloff]

The common wire is used when you're wiring in a digital t-stat. You'd have to use batteries otherwise.

[gr8gmblr]

i wish i would've found you 5 years ago when i was in a/c school. i like checking your sites out, my Fiancee' hears me talking to myself and thinks im a nut!

[DrZarkloff]

Thanks for watching my videos. I talk to myself, too.

[gr8gmblr]

thats what happens when your in a mobile office.

[hackfreehvac]

Out here most systems use the Blue wire hooked up to "C" for common or the "B" terminal on some of the older units which was for the COMMON 24V connection.

Now we get the DIY home owner who buys a HOME DEPOT low buck battery powered t-stat and the generic instructions show the Blue wire hooked up to "B" at the stat which was for some heat pump aplications. Except these usually use "O" for the rev valve and the customer thinks that the blue wire has got to be connected to something....

[hackfreehvac]

... So now Joe Homeowner wires it the way he saw in the generic instructions that are with his new t-stat and it works for the summer. But then they switch the t-stat mode switch to HEAT which connects 24VAC in the t-stat to the "B" terminal at the t-stat. But Uh-Oh. Now the Blue wire is connected there, which is now a direct short to transformer common and they blow the fuse and/or 24volt transformer. That mistake always gives you a bunch of residential calls at the beginning of winter! :-]

[DrZarkloff]

You've gotta love those calls. I don't get calls like that since I'm the one that has changed all of the t-stats in the schools that I take care of.

[hackfreehvac]

Yup. We'd get lots of those during the first cold snap when I did residential. Sounds like you take care of most of your accounts yourself. Nice gig.

[billcv80]

Gotta love those RITETEMP pos t'stats

[DrZarkloff]

lol

[SteveTx76]

excellent explanation! did not know there was a difference between O and B.

[DrZarkloff]

You'd be surprised how many people don't know the difference.

[itscool1968]

so when you comeing to maine so i can be youre tech in training:)

[DrZarkloff]

If I ever go to Maine, it would be to go on vacation. Thanks for saying so.

[mechanicwarrior20]

hmm controls :)

If only my 31 year old Lennox multizone were that simple.

Terrific job :)

[DrZarkloff]

Thanks. I wish they were that simple, too.