Question about Dayton (4LX41) Heater

4 Answers

Pilot light will not stay lit

Pilot light went out and now I can not get it to stay lit.  Solid blue flame when holding down the pilot light button but when it is released flame goes out. Start up instructions say to hold for a minute. Held it down for over two and still no luck. Do not know which part to replace.

Posted by on

  • 2 more comments 
  • joeguzman Dec 30, 2007

    My pilot light will light but will go out when I go to check it a few hours later. Also the flame in my furnace is burning very yellow and the air blown out is not that hot.

  • icemetal May 11, 2008

    I have the same problem, pilot goes out as soon as I release the button, replaced thermocouple and still does the same thing, could it be the gas valve?

  • Anonymous Jan 07, 2009

    I'm having the same problem. I've cleaned the tubing and it still won't stay lit. I'll have to try to Thermocouple and see if that does the trick!

  • Mike Powers
    Mike Powers Feb 08, 2015

    Definitely look at the thermocouple as it sounds like the gas valve isn't getting a signal from the thermocouple to stay open.



4 Answers

  • Level 1:

    An expert who has achieved level 1.


    An expert whose answer got voted for 2 times.

  • Contributor
  • 1 Answer

Clean the pliot light tube with a Q-Tip and alcohol. Clean 2 inches deep. This will increase the pilot light flame and it will heat up the thermocoupler so it will stay lit.

Posted on Dec 06, 2008

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 20 achievements.


    An expert that got 10 achievements.


    An expert that got 5 achievements.

  • Master
  • 1,420 Answers

Replace the thermocouple. It is cheap and relatively easy to replace.

Posted on Nov 02, 2007

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.


    An expert who has written 200 answers of more than 400 characters.

  • Expert
  • 484 Answers

If you\'ve engulfed the last 3/4 to 1" of the tip of the thermocouple and it is glowing red and it still \'drops out\' when the button is released, the vast majority of times it is the thermocouple at fault. VERY RARELY it is the safety \'holding coil\' internal of the gas valve that receives the millivolts generated by the thermocouple to remain open....but it does happen.

You\'ll need a 3/8" wrench for the thermocouple connection into the gas valve and possibly a 7/16" endwrench for the pilot assembly end....sometimes they are only held in with a clip and will slip out easily from the bottom. Access to the pilot assembly on the unit heater you\'ve described is by removing two 5/16" captive screws on either side of the bottom front which allows the whole bottom of the heater to hinge downward exposing all of the ribbon burners and the pilot assembly.

If your pilot flame was weak and not keeping the tip of the thermocouple red hot, now is the time to remove the entire pilot assembly from the gas valve to the burner mount and blow out with an air compressor. The orifices inside the pilot are so tiny, you cannot generate enough pressure blowing with your lips to do any serious removal of dust, lint or foreign debris that may be partiallty restricting the pilot gas flow. If you feel the need to disassemble the pilot assembly totally, you\'ll need a 1/2" wrench to hold the assembly solid while undoing the aluminum pilot tubing with the 7/17" wrench. When disassembled, tap the back end of the assembly and the tiny pilot orifice SHOULD drop out unless it is the larger type that actually screws into the assembly. Resist the urge to use a needle or pin to ream out the openings, you will render it useless and a new assembly will have to be purchased. Use the air compressor or keyboard cleaner if no compressed air is available.

Posted on Jan 10, 2015

I am having the same problem. Everthing that I have read sugests replacing the Thermocouple.

Posted on Dec 30, 2007

1 Suggested Answer

  • 2 Answers

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

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.
Good luck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%


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



Related Questions:

1 Answer

SIT 630, model 0630535 Pilot won't stay lit when button released, even after holding in for several minutes. Good pilot flame. Pilot light had been on for several weeks and went out - now can't light.

The thermal coil that tells the gas valve to stay open when the piolet light is lit is bad. Go to the hardware store with your model and serial number, they should be able to sell you a new one. They don't cost much.

Oct 28, 2017 | Heating & Cooling

1 Answer

New kozy world natural gas heater. Pilot light wont stay lit snd heater flame wont stay lit.

Are you holding down the pilot light button long enough for the heat sensor probe to get hot and turn on the gas valve? It takes up to 3 minutes

Nov 20, 2016 | World Heating & Cooling

2 Answers

When you push in the gas the red button the flame will not stay on

CTRL Z TV ' Volume 1: Introduction to the problem and ...

? 4:49
Dec 16, 2013 - Uploaded by CTRL Z TV
Which will take you from troubleshooting the problem, getting familiar ... Ctrl z TV, Pilot light won't stay lit up, Gas water heaterproblems, Gas water ... If your water heater has a thermal resetbutton, press & hold it for up to 4 ...

Pilot Light Easiest Way to Light it When it Goes Out - YouTube

? 3:06
Sep 24, 2011 - Uploaded by Mixed Martial Animations
Here's a simple solution to a common water heater problem. ... the instructions says turn off the gas valve when lighting the pilot... i... 4 Steps, Set too pilot, hold down red button, push ignitor till pilots lit, ... if the flame will not stay on no matter how long youhold the button down, your thermocouple is bad..

Nov 29, 2015 | Heating & Cooling

1 Answer

My pilot light won't stay light

Most often, this is a faulty thermocouple. Replace it, but first be sure the pilot flame is actually heating the thermocouple. If it is not, it will not stay lit. Sometimes they fall down out of it's holding bracket or just go bad. A lazy yellow pilot flame means the pilot orifice is dirty and needs to be cleaned. If the pilot flame is a string blue color, then replace the thermocouple.

Mar 17, 2015 | Heating & Cooling

1 Answer

Rheem 22V50F1 pilot won't stay lit. Changed thermo couple & it lit, ran then went out. Let it sit overnight & it lit, ran then went out. What next? p.s. The unit is 5 years old. Thanks

If pilot lights and flame is robust and clear blue, and pilot goes out later, then some suspects can be excluded: air in gas line, low gas pressure, thermocouple is overtightened (finger-tight + 1/4 turn), thermocouple not positioned correctly in the flame, dirty pilot tube.
If flame is yellowish and small: then clean pilot tube and combustion parts.
Remaining suspects can include: air in gas line, low gas pressure, bad gas control valve, tight house so household vent fans pull air down water heater vent that blows out pilot, hot attic with inadequate ventilation, water dripping down vent.

Open following links to read troubleshoot resources.

Aug 16, 2011 | Rheem 50 Gallon FVR NATGAS Water Heater...

1 Answer

I light the piuolot button and when i let go of the pilot button the pilot goes out does not light burner wont stay lit

When you light the pilot lite you have to hold the button down until it gets the element hot enough to stay lit. If you hold down the button and lite the pilot and let it go right away it will go out. What to do is hold down the button and lite the pilot and continue to hold the buttn down for about 45 seconds to a minute then let it up very slowly and you will see if it is going to go out by the flame getting smaller as you let up on the button. If it does start to get smaller conitnue to hold it again for a few seconds and repeat the process of letting it up slowly. when the control element gets to the right temperature it will stay lit then turn your valve to "ON" and the fire will start up and continue to heat the water.


1 Answer

Pilot turns on but when I switch to turn it on,

When you light the pilot, are you holding it down for 30-60 seconds. When you release the pilot button, does the pilot flame stay lit? Or does it only go out when you turn the knob to on position. Make sure the pilot flame is heating the end of the thermocouple and that it's a strong blue flame, not a lazy yellow pilot flame. Make sure the tip of the thermocouple is not burn't off, which usually happens with lazy yellow pilot flames. Replace thermocouple is nothing else works.

May 13, 2010 | Coleman 5040-751 BackHome Open Flame Patio...

1 Answer

Pilot wont light

If the pilot light goes out when you release the primer,then the thermocouple is bad.You can try to adjust the thermocouple,if it can be.It needs to be in the pilot flame.If the thermocouple is not in the flame,it will not stay lit.If you can not get the pilot to light at all,with the primer pushed down,then replace the regulator.To light the pilot light,you need to turn the dial to pilot.Then press the primer button down and hold it.The primer is either built into the turn knob,or it is a res button.Hold the primer down,and light the pilot,continue holding the primer down for at least 40 seconds.Then release the primer slowly,and if the pilot light starts to get weak,and try to go out,then push back down,and hold 30 seconds more.After the pilot stays lit,turn the knob to furnace or low,or whatever the directions say.

Oct 19, 2009 | Heating & Cooling

1 Answer

Cannot get my pilot to stay lit

Make sure the thermocoupler is about 1/4 in in the flame of pilot. If it persists, as you say it is, the thermocoupler is defefective. It's that bulb in the pilot flame. Good Luck, Ned

Sep 29, 2009 | Heating & Cooling

2 Answers

Pilot light will not stay lit

is it full of dust my hot water used to do the same till i blew the dust and fluff out

Nov 18, 2007 | Heating & Cooling

Not finding what you are looking for?
Dayton (4LX41) Heater Logo

1,863 people viewed this question

Ask a Question

Usually answered in minutes!

Top Dayton Heating & Cooling Experts

Paul Carew

Level 3 Expert

3182 Answers

Mack Baxter

Level 3 Expert

383 Answers

Dan Webster
Dan Webster

Level 3 Expert

8220 Answers

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

Answer questions

Manuals & User Guides