Question about Ruud UBHC Air Conditioner

1 Answer

Thermostats being replaced often

One customer has had 5 new stats on 2 different systems. What should I look for? Transformer or house voltage issues or grounding issues?

Posted by on

1 Answer

I have repaired A/C commercial and in dustrial for 40+ years. ( ot of ten times replacing one item as a t-stat 5 times pretty much proves it is not the thermostat. The VA rating on your transformer has to ne able to carry the total load of your circritry.

Yes, I have als seen cases wher a intermitent short occurs in the thermostat cable that has up to 6 different wires in it.

Also "Heat anticipators" in all t-stats (Unless they are automatically controlled) need to be set properly.

You need a AMP reading meter with a Volatage and Resdistence Meter.

I suggest calling a professional. ONE WHO IS LICENSED TO WORK ON THE MODEL OF AIR HANDLER AND CONDENSER YOU HAVE. THE T-STAT MUST BE WIRED CORRECTLY TO THAT SYSTEM. TRANE, CARRIER, RUUD, GOODMAN, ALL ARE DIFFERENT IN COLOR CODES FOR WIRING.

I had one job wher a painter had nailed through the t-stat wire inside the wall and caused a short between the Red (Hot wire) and the ground wire ( in this case it was the blue wire) Depending on the t-stat ... There ar up to eight terminals that need to be i9dentified and then properly wired.

Heat pumps use at least 5-6.

5 t-stats failing is gettin close to $500 of repairs if not more.

Posted on Feb 09, 2008

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

04 lincoln ls 3.0 do i need to replace the thermostat housing water outlet and the gaskets when replacing the thermostat


No

Thermostat & "o"ring

I would just try to get in there & separate
the housing & leave as much else alone
as possible

May be easier to get from the bottom

I have a 2004 V8 so I have different issues

Before you buy the thermostat, look at scan tool data
& coolant temp & remove the stat & check the temp
stamped on it,so you get the correct one

Then recheck your data under same run time,ambient
temp,etc, to compare new stat

Make sure you mix ONLY Zerex G-05 & Distilled Water
from the super market ---- NEVER TAP WATER IN
ANY COOLANT SYSTEM

You only getting 50 % out, with the radiator plug out,so
change every 3 years

I mix 60% coolant & 40% water

50/50 is okey

Nov 14, 2014 | Cars & Trucks

1 Answer

Where is the low voltage 24 vac transformer located?


The transformer is located in the furnace. You might want to check to make sure the furnace door is on correctly brcause theres a swich that will open for safety . Also some have a fuse on the solid state board.

May 26, 2014 | Rheem RASL024JEC-RHPNHM2421JC 2 Ton 18.50...

1 Answer

I replaced an old mercury T-stat (York with model number 2TH11704024) installed a new T-stat (RTH6350). The wires that I I have are O (orange), G (green), Y (yellow), T (gray but not used in new T-stat),...


Did you shut the power off to the air handler/furnace...... before you installed the new thermostat??? You may have shorted out the transformer or blown the transformer fuse...... If you try to put the Fan switch on the stat to Fan ON does the fan come on ..... if it does the transformer is OK.. On the new thermostat did you program it to tell it that you had a heat pump system ???? Looks like you had it wired right. Here is a pdf manual for a RTH6350 http://customer.honeywell.com/techlit/pdf/PackedLit/69-2416ES.pdf

Its on page 13 Advance setup for tell the new stat that you have a heat pump....There is also a Honey well Hot line on page 2 Hope this helps.

May 01, 2011 | Heating & Cooling

1 Answer

I have no voltage to my thermostat


Hi, I am not positive the control voltage to your thermostat will be on a RV a/c, most homes are 24 volts. I know yours would be less. If you have a 2-wire stat and this a/c is not working, take the two thermostat wires a touch and hold them together. Don't worry as this is safe and will not shock you. If the unit comes on and runs, you do have voltage there but the meter may be set wrong. If nothing happens, then you need to find the breaker for this unit to see if it as tripped. Reset it anyway. If still no power, you will need to find the transformer for this unit and check for power to it which will be high voltage/primary and power out which is the secondary low voltage which controls all low voltage controls such as the stat. If you have a wiring diagram on the condenser up top or most RV have a large book that tells you about your coache. If you have a diagram look for the thermostat as it will be labeled in the legend as a T with a circle around it or it may say stat. Follow to see where it gos from there, to the transformer or what and let me know. If the unit does fire when you jump out the stat wires, you will have to replace the stat. Please keep me posted on this. You may have a blown fuse up top cutting off power to the transformer also. You can ohm them out also. Keep me posted so we can solve this.
Sincerely,
Shastalaker7

May 11, 2010 | Dometic Rooftop RV Air Conditioner

1 Answer

I replaced my thermostat last night without


check for 24 volts ac at R & C terminals at the t-stat. Your transformer will have 4 wires hooked up to it. Two on one side and two on the other. Two of them will read either 120v or 240 v ac depending on whether you have a 120 or 240 v voltage. The other side should read 24 volts. If you are not reading 24 volts, then you have burnt the transformer and will need to replace it. If you are reading 24 volts, check to see if there a low voltage fuse located on the control circuit board or somewhere between the transformer and "R" terminal.
Here's a picture of a typical low voltage transformer found in an A/C system:


If you replace the transformer, add a 5 amp fuse on one of the 24 volt leads......this will save you from having to replace another transformer in the event of future "short" in the low voltage circuit.
Contact me with any questions or concerns.

I hope you find this to be very helpful to you moving forward,

Please leave a rating. :-)f0b3aee.jpg

May 09, 2010 | Heating & Cooling

2 Answers

The heat was working and then i turned it to cold and now the thermostat wont work and it is new cant get the heat or air to come on


Sounds like you had a direct short on the 24v side
of the transformer. Usually there is a inline fuse that
will blow so it protects the transformer..

Turn power off to unit
-Take doors off unit
-Look for a little fuse that may be located on the
control board where the thermostat wires go.

-Check the fuse, if it is blown then replace. However
you need to check the thermostat and the wires
that go to it to make sure they are not touching.

-If the fuse is not blown, then at the thermostat put
the fan to the on position. Go to the unit and turn the
power on, if the fans starts then things are at least
looking better. If the fan doesnt start, check to see
if the 110/220 fuse or breaker that you have isnt tripped

Jan 18, 2010 | Honeywell Programmable Thermostat Heater

1 Answer

I want to install honeywell RTH 221 thermostat.Thr thermostat operate 2 AAA batteries. the thermostat remote the heating system selonoid valfs. They works with 220 volts.My question is can I connect the...


If your old stat operated on high voltage ( anything over 24 volts) then the answer is no. However by adding some relays and a transformer you can use that stat.

Jan 15, 2010 | Honeywell Programmable Thermostat Heater

1 Answer

I have an older square mercury Honeywell thermostat in my apartment. Furnace works fine in the main house using same model Honeywell thermostat. There is no heat coming from the apartment baseboards. I...


should have 24 volts @ t-stat. if tis is a boiler system it could have air in the zone that stays cold. bleed the radiator out and this should get the heat into the area you want.

Dec 06, 2009 | Honeywell Programmable Thermostat Heater

1 Answer

I bought new Honeywell non programmable,letters are different.


If you have a 5 wire thermostat then you have a two transformer system a cooling transformer and a heating transformer.
The cooling transformer wires to Rc - Y - G,
and the heating transformer wires to R - W the R terminal heating would be the #4 terminal from the old stat.

Aug 12, 2009 | Honeywell Electronic Programmable...

Not finding what you are looking for?
Ruud UBHC Air Conditioner Logo

110 people viewed this question

Ask a Question

Usually answered in minutes!

Top Ruud Heating & Cooling Experts

Donni Steen

Level 3 Expert

659 Answers

Bill Long

Level 3 Expert

587 Answers

Tim Whalen

Level 3 Expert

3072 Answers

Are you a Ruud Heating and Cooling Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...