Gas fire place won't start

[ccpyue]

Hi, I have a gas fire place. Last winter it was still working fine. This winter, the pilot is lighting up as normal, but when I tried to turn it on, fire won't start at all. I have checked to make sure the gas switch is at "ON" position. I also checked the main gas valve is also at "ON". I wonder who can tell me where went wrong.

Thank you very much.

 

[Snoonyb]

Two possibilities; Small spiders may have built a web in the gas line restricting the flow, or the valve has failed and needs to be replaced.

 

[ccpyue]

Hi Snoonyb, thank for input. I will try to use a vacuum to clean the gas line first, to see will that help. If not, it mean I have to replace the whole unit as I circled in the photo attached? Is so, I think I need a licensed gas company to do that.

 

[Snoonyb]

There is something else you can try. If the pilot is lit continuously, it is called a standing pilot and the flame surrounds a small tube that generates a millivolt signal that allows the burner to be controlled, or switched.

This may be corroded or have failed. You can sand it with an emery board or fine sandpaper and if that cures the issue, then it is time to replace just that, the pilot generator.

 

[maxdad118]

Try jumping it at the top and bottom screws to verify it comes on. The top 2 connections appear to be your pilot generator connections and the top and bottom are the wires for the switch. If it does, it may be a bad switch or connection at the switch, something to try...But yes, the generator needs a good flame hitting it.

 

[Sparky617]

I had an issue with mine years ago where the flex gas line got pushed into the control and grounded out the switch. I moved the line and it started. It doesn't look like that could be your problem. My point is sometimes it is something pretty simple, well simple once you figure it out.

 

[ccpyue]

Thank you so much for all the valuable inputs. This weekend, I will have all tolls ready and sit tight to try every possible ways one by one. Hope the problem will solve. Thanks again!

 

[maxdad118]

Take a pair of needle nose pliers an open them enough to touch the top and bottom screws on the control valve(item you circled above)...don’t worry, it’s DC millivolts and you won’t get shocked.

 

[ccpyue]

Hi maxdad118, it looks like a little bit scarily, but I want to try is out. So shall I first lit up the pilot light, turn the fire place to "ON", and then "short" the two screws (as per photo attached in BLUE color)? If this is the value problem, the fire should start?

 

[maxdad118]

Correct

 

[ccpyue]

Today, I tried out the works. I first lightly sand the sensor next to the pilot light. Lighted up the pilot, then turn on the fire place, but fire won't start. Then I used a pliers tip to to connect the up and down two screws, fire started.

Now what is that means? Is it the sensor problem or else?

 

[maxdad118]

I would now check your switch connections, jump the 2 wires going to the switch. If it comes on you may have too much resistance at the switch(bad sw) or a bad connection.

 

[ccpyue]

Hi maxdad118,

Bingo! Yes, this is the wall switch problem. I used sand paper lightly sand the contact (see the photos attached), and now the fire place works perfect.

Since my wall switch is very old, I am looking to get a replacement one. Do you know what is this switch calls, and where can I get a modern one?

Thank you so much for your assistance, save me lots of money to find a contractor to check.

 

[Sparky617]

I had that happen on my thermostat at a new house I bought 30 years ago. The contacts on the thermostat got some paint on them from the spray painting of the house during construction. Weird thing was it worked fine in the heat mode, it didn't work in the AC mode. Interesting you have a wall mounted thermostat for your gas fireplace.

 

[ccpyue]

This wall switch is solely for the fire place. It hard-wired to the sensor next to the pilot light in the fire place. It said it is a "millivolt" switch, but I really don't know how it works. Just know there are two contact points inside the wall switch. Once they touched, fire starts.

 

[maxdad118]

Awesome, get a simple millivolt HEATING ONLY thermostat, avoid ones that say fan on/auto or cool..glad everything worked out. Or just keep using that same one? Make sure your connections are tight and maybe refresh those connections? Save your money

 

[ccpyue]

Yes, I will still keep using this old one, as it works fine. Just polish up a little bit will do. Thanks maxdad118 for all the help.