HVAC

Have HVAC questions? Ask an HVAC Expert for answers

Ask an Expert,
Get an Answer ASAP!

We just came home from work and our house is absolutely

Customer Question
We just came home...

We just came home from work and our house is absolutely freezing. The thermostat digital screen was blank so we changed the batteries. It seems to work for a moment and then starts to fade again and eventually goes completely blank. We've tried three different sets of AA batteries and the same thing keeps happening.

Contractor's Assistant: Just to clarify, do you think this is a larger HVAC problem, or something specific to the thermostat?

Thermostat

Contractor's Assistant: Do you plan on doing the work yourself?

Yes

Contractor's Assistant: Anything else we should know to help you best?

If we xan

Submitted: 9 months ago.Category: HVAC
Show More
Show Less
Ask Your Own HVAC Question
Answered in 2 minutes by:
12/9/2017
HVAC Technician: BillyHvac, Journeyman HVAC Tech replied 9 months ago
BillyHvac
BillyHvac, Journeyman HVAC Tech
Category: HVAC
Satisfied Customers: 23,178
Experience: Endorsed for unlimited heating, cooling, oil burners, boilers, refrigeration, hydronics
Verified

Hello,

My name is Billy. If you do not mind some hands on we can start trying a few things. You will likely get a computer generated offer for phone contact but please disregard as I am not set up for phone contact currently.

Do you mind removing the top portion of thermostat to where we can see the wires?

Ask Your Own HVAC Question
Customer reply replied 9 months ago
It's working for the moment...should we try anyway. The display has been on for about 3 minutes and the heat is running.
HVAC Technician: BillyHvac, Journeyman HVAC Tech replied 9 months ago

Ok, is the filter ok?

There are a couple things that cut power to thermostat...over heating is one.

If it is running right now I recommend letting it heat things up first

Ask Your Own HVAC Question
Customer reply replied 9 months ago
We changed the filters about 30 days ago. We had this happen a few months ago when it was hot outside and the AC wouldn't run while the thermostat was blank. We changed the batteries and it seemed to be fine until today. But honestly, we hadn't changed the batteries before that for probably a few years.
HVAC Technician: BillyHvac, Journeyman HVAC Tech replied 9 months ago

Does the furnace drain water (90% efficient)?

Ask Your Own HVAC Question
Customer reply replied 9 months ago
We don't understand the question? We've never checked the furnace for water.
HVAC Technician: BillyHvac, Journeyman HVAC Tech replied 9 months ago

90% furnaces drain condensate.

80% furnaces do not.

The other thing that cuts power to thermostat is a water safety switch.

Does your furnace put exhaust out through a metal pipe to chimney or the side of house with plastic pipes?

Ask Your Own HVAC Question
Customer reply replied 9 months ago
Side of the house with plastic pipes
Customer reply replied 9 months ago
The furnace seems to be working when the thermostat display is. It's when the display goes blank that the unit turns off.
HVAC Technician: BillyHvac, Journeyman HVAC Tech replied 9 months ago

Ok this furnace drains water during ac and heating also.

It may come out side of furnace and go to a small pump that sits next to furnace or to a floor drain.

Can you see or post a pic of the furnace here using the attach files link?

Ask Your Own HVAC Question
Customer reply replied 9 months ago
We have 2 units. One is in each attic. It's the downstairs thermostat having issues. How do we know which one that is?
HVAC Technician: BillyHvac, Journeyman HVAC Tech replied 9 months ago

Ok attic units have water safety devices that turn power to thermostat off if water is draining too slow.

I would turn off the other unit at thermostat right now...and leave the one we are talking about running...then go to attic and see which one is running

Ask Your Own HVAC Question
Customer reply replied 9 months ago
Ok going up to check now. Stand by please.
HVAC Technician: BillyHvac, Journeyman HVAC Tech replied 9 months ago

you see a water switch can cut power to thermostat...drain...restart....backup water...cut power......drain...repeat

Ask Your Own HVAC Question
Customer reply replied 9 months ago
We're checking.
Customer reply replied 9 months ago
No water at all in either drain pan...not a drop. We checked both units.
HVAC Technician: BillyHvac, Journeyman HVAC Tech replied 9 months ago

That is not where the switch would be....does the furnace drain into a pump?

Ask Your Own HVAC Question
Customer reply replied 9 months ago
The downstairs unit is still running and the thermostat is steady display. Makes no sense.
Customer reply replied 9 months ago
Do you think it's the thermostat itself?
HVAC Technician: BillyHvac, Journeyman HVAC Tech replied 9 months ago

The water safety switch is in the pump or drain line not the pan..the pan is safety catch in case of overflow.

This fits your description as to what could be happening. If you want to eliminate thermostat just swap the 2 and see if issue stays with same system or moves

Ask Your Own HVAC Question
Customer reply replied 9 months ago
Ok sounds good. We aren't sure where the drain is so aregoing to wait until daylight and warmer temp to explore. Thank you very much! You've been very helpful. We will come back to this if we are still struggling tomorrow.
HVAC Technician: BillyHvac, Journeyman HVAC Tech replied 9 months ago

Just respond as you need more information

Billy

Ask Your Own HVAC Question
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a hvac technicianLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask BillyHvac Your Own Question
BillyHvac
BillyHvac
BillyHvac, Journeyman HVAC Tech
Category: HVAC
Satisfied Customers: 23,178
23,178 Satisfied Customers
Experience: Endorsed for unlimited heating, cooling, oil burners, boilers, refrigeration, hydronics

BillyHvac is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

You did one super job of explaining to me everything there is to know about this fridge. I'm looking forward to asking you questions in the future.

JimmyBagley, IA

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

< Previous | Next >

Meet the Experts:

Phil

Phil

Mechanical Engineer

7,634 satisfied customers

Retired HVAC/ Electrical & Boiler contractor. Industrial

Rick Mather

Rick Mather

HVAC Technician

3,133 satisfied customers

35 years experience, HVAC

Matthew

Matthew

HVAC Technician

2,014 satisfied customers

14 years experience in the HVAC field of service, installation, Manual J & D calculations

Brian HVAC Guy

Brian HVAC Guy

HVAC Technician

1,024 satisfied customers

I have been an HVAC/R mechanic/technician for 30+ years.

Kenton Guidry

Kenton Guidry

HVAC Technician

963 satisfied customers

12 years install/service experience.

Rick Ridley

Rick Ridley

UK Heating Engineer

871 satisfied customers

Retired But have had 30 years on the tools, Ex CORGI

Tom

Tom

HVAC Technician

770 satisfied customers

16+yrs HVAC/R service. Residential Commerical Industrial

< Previous | Next >

Related HVAC Questions
MY thermostat screen is blank and the unit is not working. I
MY thermostat screen is blank and the unit is not working. I changed the batteries. No difference. I do not have the manual booklet that came with the unit. Can you help me trouble shoot to find the p… read more
Airheatman
Airheatman
Heating & Air Conditioning Contractor
6 years college
1,836 satisfied customers
My thermostat is frozen. Says hold battery. Changed
My thermostat is frozen. Says hold battery. Changed batteries. Will not turn on. Please help! … read more
HVAC Guru
HVAC Guru
Service Technician
Associate Degree
682 satisfied customers
My batteries went dead and I replaced them with carbon zinc
My batteries went dead and I replaced them with carbon zinc AA not knowing I should have used alkaline AA batteries , I just changed over to alkaline and didn't switch the system to OFF then I switche… read more
Rick the plumber
Rick the plumber
Owner
9,857 satisfied customers
My train thermostat screen is blank, i came home and it was
i came home and it was blank. i pressed on the screen and it came back on. house was at 83. i had it set for 80. i turend it down to 78 and after a few minutes the fan came on, but not blowing very hard. i left for an hour or so, house wasn't too hot, and screen is blank again … read more
Airheatman
Airheatman
Heating & Air Conditioning Contractor
6 years college
1,836 satisfied customers
Came home last night to no heat. We have a trance forced air
Came home last night to no heat. We have a trance forced air gas heater and outside separate AC unit. The first thing I noticed, other than the thermostat was reading 59 degrees was that it was flashi… read more
Rick the plumber
Rick the plumber
Owner
9,857 satisfied customers
I have replaced the batteries in my lux thermostat and am
I have replaced the batteries in my lux thermostat and am still get a Lo batt flashing signal..… read more
Heath.M
Heath.M
Refrigeration Mechanic
Vocational, Technical or Trade School
223 satisfied customers
Is there a reason why some batteries work in my thermostat
Hi, Is there a reason why some batteries work in my thermostat and others don't? We bought the house over two years ago and we're replacing batteries for the first time. I put brand new Alkaline AAs i… read more
Wvfan79
Wvfan79
Mecanical Designer & Estimator
High School or GED
775 satisfied customers
I have the RTH230B t-stat and just changed batteries. Im getting
I have the RTH230B t-stat and just changed batteries. I'm getting a blank display on the cooling setting and time (12:00) and temp on the heat setting. I'm trying to set the cooling but have a blank s… read more
Heath
Heath
Vocational, Technical or Trade Scho
1,002 satisfied customers
We have model #1F78 thermostat. Weve had our thermostat in
We have model #1F78 thermostat. We've had our thermostat in the off mode, today due to the weather we turned it to the heat mode. Nothing happened. We tried the program button, run button, hold button… read more
Heath
Heath
Vocational, Technical or Trade Scho
1,002 satisfied customers
the screen of my thermostat is blank (I can see the outline
the screen of my thermostat is blank (I can see the outline of the boxes that say system and fan,also the up and down arrows can be seen) I replaced the batteries with two AA's (Duracell) and nothing … read more
gotoman for ac
gotoman for ac
HVAC Service manager and owner
Associate Degree
4,135 satisfied customers
The digital screen on my rth230b thermostat is blank. Changed
The digital screen on my rth230b thermostat is blank. Changed batteries, tried to reset. Nothing worked. Please help.… read more
gotoman for ac
gotoman for ac
HVAC Service manager and owner
Associate Degree
4,135 satisfied customers
We have a 3611 thermostat which is now showing a blank screen.
We have a 3611 thermostat which is now showing a blank screen. we've tried circuit breakers, and they're fine. Are there batteries in this unit that need to be changed? I can't find them if they are. … read more
BillyHvac
BillyHvac
Journeyman HVAC Tech
State Licensed Mechanical Contractor
23,178 satisfied customers
I have a Honeywell MagicStat programmable thermostat. Three
I have a Honeywell MagicStat programmable thermostat. Three days ago the Bat Lo indicator started blinking. It said we had 1-2 months before power absolutely failed so we were going to buy brand new A… read more
BillyHvac
BillyHvac
Journeyman HVAC Tech
State Licensed Mechanical Contractor
23,178 satisfied customers
i have a honeywell thermastat rth230B- theh screen was fading
i have a honeywell thermastat rth230B- theh screen was fading all day so i changed the batteries- now the screen is BLANK only when it is in heat mode- i cant see anything and the only way to get the … read more
M Oglesby
M Oglesby
Vocational, Technical or Trade Scho
2,010 satisfied customers
We have two Invensys 9400 thermostats in our house that use
We have two Invensys 9400 thermostats in our house that use up the two AA alkaline batteries every three months. Is this normal? Should we use rechargeable NiMH batteries to get longer life? Or is the… read more
Mark Henley
Mark Henley
HVAC Controls DDC
3,209 satisfied customers
I have a digital thermostat. I changed the batteries, my boiler
I have a digital thermostat. I changed the batteries, my boiler is on & the screen shows the time and temp. I am, however, unable to set the time, the schedule or change it to a 'hold' temperature. Th… read more
Heath
Heath
Vocational, Technical or Trade Scho
1,002 satisfied customers
I have a White-Rogers Thermostat. Suddenly, today we got home
I have a White-Rogers Thermostat. Suddenly, today we got home and the air conditioner wasn't working. We looked at the electronic thermostat and it showed a signal saying 'battery'. We replaced the ba… read more
Heath
Heath
Vocational, Technical or Trade Scho
1,002 satisfied customers
The digital thermostat is blank, no heat in the house and power
The digital thermostat is blank, no heat in the house and power is OK. What should I check. House is cold.… read more
Jason  Hvac
Jason Hvac
Hvac Tec
Vocational, Technical or Trade Scho
120 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x