HVAC

Have HVAC Questions? Ask an HVAC Expert for Answers

Ask an Expert,
Get an Answer ASAP!

HVAC

I have a Reznor UDAP 125 unit heater running on propane

Customer Question
heating my garage. Recently the...
I have a Reznor UDAP 125 unit heater running on propane heating my garage. Recently the heater has begun shutting off before it reaches the thermostat's set temperature. The green light flashes continuously indicating a continued demand for heat and there is a high pitched noise coming from the circuit board when it shuts down. If I shut the power off and wait fifteen minutes the unit will re-fire and run for awhile then do the same thing. What would be causing this?
Submitted: 1 year ago.Category: HVAC
Show More
Show Less
Ask Your Own HVAC Question
Answered in 29 minutes by:
1/24/2016
HVAC Technician: airheatman, HVAC Technician replied 1 year ago
airheatman
airheatman, HVAC Technician
Category: HVAC
Satisfied Customers: 8,516
Experience: Furnace, A/C and heat pump specialist.
Verified

Do you get any other error code when it shuts down prematurely?

Ask Your Own HVAC Question
Customer reply replied 1 year ago
green fast flash
HVAC Technician: airheatman, HVAC Technician replied 1 year ago

OK usually if heater is turning off before thermostat is satisfied, a limit or pressure switch is opening but we should get a different code if it does.

Ask Your Own HVAC Question
Customer reply replied 1 year ago
That's what I had thought. I'm not sure what I should be doing next.
HVAC Technician: airheatman, HVAC Technician replied 1 year ago

I would start by cleaning flame senser . If that doesn't solve, try to catch it fail and immediately ohm the limits and pressure switch to see which one is open if any

Ask Your Own HVAC Question
Customer reply replied 1 year ago
I watched it tonight. It runs along with the green light flashing quickly and the orange light lit for quite some time then the flame just stops. and the orange light goes out as the green light keeps flashing fast. the back fan keeps running but the combustion fan shuts off. If I shut the power off and then attempt to restart the green light continues to flash fast but when I hear the on solenoid click there is a high pitched sound that seems to be coming from the transformer. If I shut it off and allow everything to sit for fifteen minutes or so I can flash it back up for awhile and then it does the same thing again. I think there must be a problem with the transformer overheating.
HVAC Technician: airheatman, HVAC Technician replied 1 year ago

Do you have a meter to see if transformer is bleeding down?

Ask Your Own HVAC Question
Customer reply replied 1 year ago
I have a multi meter but I'm not quite sure what I should be checking
HVAC Technician: airheatman, HVAC Technician replied 1 year ago

Transformer should have 4 wires.2 supplying high voltage to transformer and two (going to relays and thermostat) 24 volts. If thermostat is issue, the 24v will drop.

Ask Your Own HVAC Question
Customer reply replied 1 year ago
Any idea which colour wires will be carrying which current?
HVAC Technician: airheatman, HVAC Technician replied 1 year ago

Nope.......LOL. Give me a minute to pull the manual and see if it shows me.

Ask Your Own HVAC Question
Customer reply replied 1 year ago
Okay I'll check that out
HVAC Technician: airheatman, HVAC Technician replied 1 year ago

Let me know what you find

Ask Your Own HVAC Question
Customer reply replied 1 year ago
Will do, Thanks
HVAC Technician: airheatman, HVAC Technician replied 1 year ago

Thanks for letting me work with you to this point

Ask Your Own HVAC Question
Ask airheatman Your Own Question
airheatman
airheatman
airheatman, HVAC Technician
Category: HVAC
Satisfied Customers: 8,516
8,516 Satisfied Customers
Experience: Furnace, A/C and heat pump specialist.

airheatman 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

6,730 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

Kenton Guidry

Kenton Guidry

HVAC Technician

963 satisfied customers

12 years install/service experience.

Brian HVAC Guy

Brian HVAC Guy

HVAC Technician

953 satisfied customers

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

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
Maybe, just one day. I just installed a reznor udap 150 unit
just one day. I just installed a reznor udap 150 unit heater replacing my old unit heater. it fires up for about 3 minutes then cuts out even though the thermostat is still calling for heat … read more
airheatman
airheatman
HVAC Technician
8,516 satisfied customers
I have a Lennox unit heater and have recently puchast a new
I have a Lennox unit heater and have recently puchast a new circuit board, only upon installation I found that the plug in does not match as it has six plug in as the old one has nine, where can I fin… read more
airheatman
airheatman
HVAC Technician
8,516 satisfied customers
JUST INSTALLED MODINE GAS FIRED UNIT HEATER TO REPLACE OLD
jUST INSTALLED MODINE GAS FIRED UNIT HEATER TO REPLACE OLD ONE WITH PILOT LIGHT. NEW ONE IS ELECTRONIC IGNITION WO WE CAN PROGRAM THE THERMOSTAT. WE HAVE A RTH2300/RTH221 HONEYWELL THERMOSTAT. THERE I… read more
Regan Land
Regan Land
General Manager
Vocational, Technical or Trade Scho
508 satisfied customers
I have a wall unit heater that has a synchronizer and a
I have a wall unit heater that has a synchronizer and a spill switch, gas valve and thermostat.. The spill switch has three wires and the synchronizer has four (two on top and two on bottom) how do I … read more
Rick the plumber
Rick the plumber
Owner
9,857 satisfied customers
Second opinion] Can anyone provide me with a wiring diagram
Second opinion] Can anyone provide me with a wiring diagram for a Coleman DFAH-084BBSA mobolehome furnace?… read more
Billy
Billy
Journeyman Service Technician
State Licensed Mechanical Contractor
9,330 satisfied customers
HVAC question I am working with a Modine natural gas unit
HVAC question I am working with a Modine natural gas unit heater, Model PAH 180 AF, serial 15012069Z.The fans come on but the unit will not ignite. The igniter has no spark. The unit has a Robertshaw … read more
Billy
Billy
Journeyman Service Technician
State Licensed Mechanical Contractor
9,330 satisfied customers
I have a Reznor natural gas unit heater in my garage. I will
Hi, I have a Reznor natural gas unit heater in my garage. I will set it to heat mode, and a pilot is lit, the main burner will light, but the fan will not start. … read more
Rick the plumber
Rick the plumber
Owner
9,857 satisfied customers
I awant to replace janitrol unit gas fired unit heater can
i awant to replace janitrol unit gas fired unit heater can you help ? … read more
Rick the plumber
Rick the plumber
Owner
9,857 satisfied customers
I have a custom ac installation i need help with. I have a
I have a custom ac installation i need help with. I have a 1500 sq ft shop with a waste oil heater and no ac. It has a very strong 4200 cfm fan. A friend gave me a 3 ton ac condenser and coil (coil is… read more
airheatman
airheatman
HVAC Technician
8,516 satisfied customers
I have a old Janitrol Unit Heater Product WH-30 that I cant
I have a old Janitrol Unit Heater Product WH-30 that I cant find a wiring diagram for the life of me. I am installing it in my small 2 car shop . I have a few wires that I am unsure of . It appears that there is two sensors inside the unit with a total of four wires - Red, Yellow, Green, Black. Any Idea of how and where to wire this. It look like the previous owner had the yellow and fan motor wire wired together, the green and the other fan motor wired together and the red and black from the sensors wired together. I have been searching for days and cant get any info. Any help would be greatly appreciated. Travis … read more
gotoman for ac
gotoman for ac
HVAC Service manager and owner
Associate Degree
4,135 satisfied customers
I have a beacon garage heater, ng, 75,000 btu. My hvac guy
I have a beacon morris garage heater, ng, 75,000 btu. My hvac guy came and hooked up the thermostat-old rotary style therm. My heater has 4 terminals for thermostat wires. R g w1 and w2. How many of t… read more
Rick the plumber
Rick the plumber
Owner
9,857 satisfied customers
I just installed a trane uhec 053daca unit in my garage
I just installed a trane uhec 053daca unit in my garage 480v.. Do I need to install a thermostat and if so to what numbers on the elec-ton board. The numbers range from 1 to 10 Thanks… read more
Brian HVAC Guy
Brian HVAC Guy
HVAC Technician
High School
953 satisfied customers
I have a reznor f200 unit heater. It is standing pilot and
I have a reznor f200 unit heater. It is standing pilot and not power vented. I pilot lights fine but when the gas valve clicks to come on, no gas comes out and the pilot dies out. I have replaced the … read more
Rick the plumber
Rick the plumber
Owner
9,857 satisfied customers
I have a DNP unit heater Model150UHE-1 16 3U S/N 19237 and
I have a DNP unit heater Model150UHE-1 16 3U S/N 19237 and the pilot light keeps going out at night. The unit runs allday ok, but pilot goes out at night. … read more
Phil
Phil
Mechanical Engineer
Degree, Mech Engr Technology
6,730 satisfied customers
Pearl. I have Armstrong cgha45ae-4 unit heater in my garage.
Hi, pearl. I have Armstrong cgha45ae-4 unit heater in my garage. Sometimes garage is cold and heater hasn't come on, … read more
Rick the plumber
Rick the plumber
Owner
9,857 satisfied customers
I have a upad75 reznor unit heater and the burner keeps
I have a upad75 reznor unit heater and the burner keeps shutting down, i have 3.5 inchs water at gas valve outlet, 0.1 mily amps from flame sensor and .932 inchs water at the inducer fan neg pressure … read more
HVAC Guru
HVAC Guru
Service Technician
Associate Degree
682 satisfied customers
I have an older Reznor unit heater that has not been used
I have an older Reznor unit heater that has not been used for a few years due to main line gas pipe failure. Finally got around to replacing the gas line and have confirmed gas to main valve. but cann… read more
Rick the plumber
Rick the plumber
Owner
9,857 satisfied customers
I have a Reznor unit heater,Model F50-E,installed in 1994.The
I have a Reznor unit heater,Model F50-E,installed in 1994.The unit will not fire at all It does nothing.I crossed the red and white thermostat wires and still nothing?… read more
Tim H
Tim H
Lead building engineer
Vocational, Technical or Trade Scho
1,922 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