Gas Valves

[etherhuffer]

Anyone replaced a gas valve on a gas fireplace? We shut ours down and unfortunatel moisture in line seized the valve. Old pilot assembly should get replaced too

 

[gmcgeo]

If methanol is not added to the propane tank from the manufacture that is a big cause of water/ moister getting into the line.

Everything about this sounds off. you should not have to replace the pilot assembly and gas valve. unless the tank was over filled and liquid got into the system.


I have replaced gas valves only due to lock up, when the magnet would not drop allowing the gas to flow. I have never had to replace do to moister

 

[engineer2]

You mean the simple 90° on/off valve or the gas control valve?

 

[gmcgeo]

You mean the simple 90° on/off valve or the gas control valve?

Thats what i thought, but then read about the pilot assembly.

 

[etherhuffer]

This is a natural gas line into a fireplace. I have check all the electrical issues with a meter, and it looks like valve is the issue, not the main shutoff valve. It is about 20 years old and nobody wants to work on it even though parts are available, likely because its a maze to tear it down and replace the valve. The pilot assembly works, but at its age a replacement pilot makes sense so I don't have to do this job twice. Sort of the timing belt/water pump deal where you fix only one and the other dies a month later. Uff da....

 

[engineer2]

Thanks for the explanation.
Moisture issues in natural gas would be uncommon, but I imagine gas quality varies around the country.
Agree it is a bit of a struggle to take it out since there is so little room to work. Get the make and model number and see what replaces it.
I replaced my Robertshaw gas valve in my fireplace. The original one failed due to a broken internal wire.
Found a replacement online at https://www.supplyhouse.com/
Use pipe dope made for natural gas, and leak check all fittings with soapy water.

 

[etherhuffer]

Yep, have dope from my water heater tank replacement, and soapy water. Found the Robertshaw valve replacement after a bit of searching. Being semi retired, a few hundred in parts sure looks better than 4-6 K for a new one. Gonna be a beast to disassemble though

 

[75gmck25]

Many gas fireplaces have the valve assembly and starter in the base of the housing, so its not easy to get to it. However, I've found that taking the fireplace apart is time consuming but not really that difficult mechanically. Its mostly simple nuts, bolts and panels that come out, then replace the valve or other important parts, and then put it back together with a screwdriver and a couple of wrenches. Just keep track of which screws or bolts go with each panel.

 

[etherhuffer]

Many gas fireplaces have the valve assembly and starter in the base of the housing, so its not easy to get to it. However, I've found that taking the fireplace apart is time consuming but not really that difficult mechanically. Its mostly simple nuts, bolts and panels that come out, then replace the valve or other important parts, and then put it back together with a screwdriver and a couple of wrenches. Just keep track of which screws or bolts go with each panel.

Exactly. Took too many years to learn that blue tape does a great job of holding nuts and bolts in locations where they need to go.

 

[rharman]

I replaced the RobertShaw valve in one of ours several years ago. Got it from Amazon. Was a piece of cake to do. Also replaced the thermopile. Was a piece of cake on our fireplace.

Probably need to replace the one in our upstairs fireplace. It's had issues for 25+ years and we just never use that one. That fireplace does not out out much heat though - more decorative. We expected more heat - the downstairs one works really well. Same manufacturer, different model.

 

[etherhuffer]

I replaced the RobertShaw valve in one of ours several years ago. Got it from Amazon. Was a piece of cake to do. Also replaced the thermopile. Was a piece of cake on our fireplace.

Probably need to replace the one in our upstairs fireplace. It's had issues for 25+ years and we just never use that one. That fireplace does not out out much heat though - more decorative. We expected more heat - the downstairs one works really well. Same manufacturer, different model.

I think since all parts are original, best to replace thermopile and thermocouple as well? Getting ready to tear this down, need to check parts availability first

 

[rharman]

I think since all parts are original, best to replace thermopile and thermocouple as well? Getting ready to tear this down, need to check parts availability first

You'll have either a thermopile or a thermocouple. I've never seen both, but I am no gas appliance expert.
While you're in there, it's cheap insurance.

 

[fitter30]

Thermocouple 25 - 30 mv
Thermopile 250 - 750 mv
Fireplace will most likely a thermopile. Pull pilot assembly just match up the numbers on it. If has a pezo push button spark igniter replace it to.

 

[4x4Pete]

Some fireplaces have both a thermocouple (for pilot safety) and a thermopile (for main valve operation and a optional thermostat) Replace both if you can. Sometimes the thermocouple is a special size. A standard one is usually too long on the business end. A lot of fireplace operational problems are related to a weak thermopile- pilot stays on but no main burner. Good clean wiring connections are paramount to smooth consistant operation.

 

[welderguy]

Anyone replaced a gas valve on a gas fireplace? We shut ours down and unfortunatel moisture in line seized the valve. Old pilot assembly should get replaced too

Shut off outside supply valve. Id try penetrant oil ,it might be just the stem . Or once supplies off unscrew fittings and replace.

 

[etherhuffer]

Thanks all. My SOP is to replace old parts as part of a teardown that is a pain to do. That said, I can test parts as I go to detect failure points. It's been a while since I checked out the unit, but I remember that I had a standing pilot but a call for gas made no click happen in the unit, no gas delivery. I found the OEM parts list and exploded diagram so that should help a lot.

 

[The Cobbler]

a buddy has a gas fireplace at least 20 yrs old. it wouldn't light. place that originally installed it said gas valve was bad, parts no longer available, buy new.
turned out to be a bad connection in the wiring from the stat. that was about 5 yrs ago & still going strong

 

[gmcgeo]

Usually what happens is when a tech or person does not understand the system fully, they go right for the gas valve being the problem.

9-10 chances it was electrical or thermocouple/pile that was the issue.

 

[HoosierBuddy]

Dumb question: You are pushing the valve in when you attempt to turn it, right?

Just that I've never run into the frozen gas valve scenario....but I've seen plenty of broken plastic valve operators where people weren't pushing in the valve before they turned it, then tried so hard they stripped the hub on the plastic operator.

I'm 99% sure that isn't your problem....just throwing in this post for the 1/100 chance you forgot to push it in.

 

[Copymutt]

Going through this right now on an older Waterford Emerald NG stove. So intermittent its difficult to pin point the culprit. It has never been 100% reliable. Calls for a 250-750 millivolt Tstat. Have changed that two yrs. ago. Yesterday it fired up everytime I shorted the two tstat wires together, this morning it never came on. I flipped the tstat up & down, no go. Went to get a paperclip & it had lit off. Inclined to replace the complete igniter, pile & couple as each is not available.

 

[gmcgeo]

Going through this right now on an older Waterford Emerald NG stove. So intermittent its difficult to pin point the culprit. It has never been 100% reliable. Calls for a 250-750 millivolt Tstat. Have changed that two yrs. ago. Yesterday it fired up everytime I shorted the two tstat wires together, this morning it never came on. I flipped the tstat up & down, no go. Went to get a paperclip & it had lit off. Inclined to replace the complete igniter, pile & couple as each is not available.

the problem is the thermostat wires to the switch. if it comes on at the gas valve by jumping the wires there

 

[etherhuffer]

Dumb question: You are pushing the valve in when you attempt to turn it, right?

Just that I've never run into the frozen gas valve scenario....but I've seen plenty of broken plastic valve operators where people weren't pushing in the valve before they turned it, then tried so hard they stripped the hub on the plastic operator.

I'm 99% sure that isn't your problem....just throwing in this post for the 1/100 chance you forgot to push it in.

Yes, did that. And used a meter on thermostat and all other electrical connections. One thing I noticed is that I don’t see a drip leg in the gas run. And this is lowest point in the system.