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 Posted: Thu Nov 15th, 2007 03:45 am
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joei1977
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I have a natural gas water heater, and the gas was turned off to it from may, until this past week.  I have called the gas company, a furnace, and the local hardware stores to find out how to bleed (or purge ) the air from the lines, so that gas will start flowing, so i can once again relight the pilot light.  I live in a small rural area, where there is not much knowledge about natural gas, and there are no plumbers in this area, that are qaulified to touch the gas equipement, and therefore will not. I have not been able to find anyone that can help me with this problem.  Can you please tell me how to do this myself cause cold showers are about to kill me?  I tried holding down the p-ilot light button, even went so far as to simply turn the water heater to the on position, and hoiped it would push the air out that way, with no luck.  Please, Please Help me.  I hold no one responsible for my actions except mysyself, and would greatly appreciate the information. 
Thank you, Heather

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 Posted: Fri Nov 16th, 2007 04:39 am
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eleent
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Hello:  What you ask is not so difficult to do, but can be exceedingly unsafe, done wrong :shock:  Also, there is this nagging question of why should there be no gas in the line, even though it's been a long time since it was used.  I don't have an answer for that one. 

I'll assume the heater is indoors.  With gas shut off at the shut-off valve, which will be in the pipe, near the water heater, unhook the flex connector (or union) from the water heater.  Find some hose large enough to fit over the end of the gas line (may need to get creative here).  Make sure the hose is dry inside.  There must not be water to block gas flow.  Also, no kinks in the hose are allowed.  Thoroughly seal the hose to the gas line with tape.  Run the hose outdoors to a safe place.  There must be no possible sources of combustion or anything which could trap the gas near either end of the hose.  Note that this won't safely work for propane gas, which is heavier than air.  Once the hose is securely fastened and led outside you can turn on the gas valve.  Let it run only five seconds.  Undo the hose and hook up the connector back to the heater.  Hold down the pilot button for a minute to bleed air from the control but try lighting the pilot every ten or fifteen seconds.  Once the pilot lights, hold down the button for another minute and then slowly let it up.  The pilot should remain lit.  Now replace hatch covers and turn the heater to "on" and turn the thermostat up to the temperature you want. 

This assumes no problems with the gas supply or piping.  Can I assume you do have other gas equipment and it's working correctly?

Do let us know how it goes.  If any of this is uncomfortable to you, get help!

Yours,  Larry

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 Posted: Sun Dec 2nd, 2007 06:18 pm
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joei1977
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thank you very much for the instructions on how to bleed the gas lines.  I found the problem before i got your reply, and it was only a kink in the flexible gas line that was causing the problem.  Once I straightened out the kink, (and removed the insulation mice had packed into the bottom, LOL) I had no problem getting the water heater to light.  I appreciate the information you sent me, and will be printing them out, along with lighting instructions for future refernce.  (Just incase, you never can tell.)  Again thank you, your reply was very easy to understand, and i do appreciate your assistance in the matter

 

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 Posted: Sun Dec 2nd, 2007 08:03 pm
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kstjohn
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OK, great answer! I have the similar issue except that - what would you do differently to make sure ALL of the other appliances are not going to be connected to lines with air in them? I live in a 2-story house with basement. Gas fireplaces on 2nd floor, gas fireplace/gas stove on 1st floor, heater/water heater in basement. Does the weight of the gas have anything to do with where you bleed from? I was thinking maybe the lowest point of all the lines as air is heavier than NG.  Really be interested in the proper way to do this before I open my lines to add a new 2nd water heater.

Ken

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 Posted: Mon Dec 3rd, 2007 11:37 pm
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eleent
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Hello:  If you're going to cut into the gas line, add a "T" and run a new line, gas to the house will need to be turned off.  When you are done plumbing, bleed gas from the farthest place you can.  This will purge air from the gas line as well as can be done.  You will probably still have to hold the pilot button down more than once for some appliances, but they should not need "bleeding" as done from the farthest appliance.  By farthest, I mean from the gas meter ;) 

Natural gas is lighter than air, so purging the line should be done pretty wide open (safely) to push the air out, wherever it may be in the system.  You will probably want to purge the line you install to remove air and any debris that could be hiding in the new pipes.

Another possibility for purging the old lines is with a gas dryer.  These are usually hot surface ignition and will try to relight themselves if air in the line puts out the burner.  The advantage of course, is that you don't need to mess with hose, tape and worry :cool:

And, just to be clear...  paying a technician is cheap compared to hospital bills and rebuilding the house after things have gone badly :shock: STAY SAFE!

Yours,  Larry

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 Posted: Tue Dec 4th, 2007 01:01 pm
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kstjohn
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Thanks Larry! Exactly what I needed to know! I wouldn't even attempt the job if I wasn't confident in it's outcome! I have a pretty healthy respect for flamable gasses as we work with propane and acetylene on a daily basis. Your answer jibes with my original assumption as to how to go about this. The new line will terminate at the lowest point in the entire house piping system and also at the farthest from the main point of supply. Also, it terminates to a ball valve shutoff and a connection that accepts the flexible hose that will run to the gas compressor. This is an easy bleed point as I can connect the hose to this shutoff valve an stick it out a nearby window to the outside. I figure when all is done I can open this valve and safely bleed as much gas outside as necessary. By the way, as an FYI, I purchased the parts for this 14' run yesterday for $46. I also received a quote for $700 from a popular local plumbing company. Not that I'm price foolish here but, difficult to justify the extra $650 for something I know I can do - and probably a better job as well.

Thanks again for your counciling and reality check!

Ken

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 Posted: Wed Dec 5th, 2007 05:06 pm
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kstjohn
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Larry, thanks again for the advice. It went off without a hitch yesterday and no problems relighting any appliances. Checked with nose test and soap bubbles. Might point out that Lowes did have a combo CO2 + Explosive Gas monitor for $50 which I used as the final check for leaks. The local plumber quoted $725 for this job which I did for $46 in materials. The $50 for the monitor I didn't count as this will be permanently installed in the ceiling of the basement over the supply lines.

One lesson learned when tightening a fitting to its final position, was to allow the final adjustment "torque" to pass downline to other pipes and fittings in the install by releasing the hold on its pipe. This way, you spread out the rotation among multiple joints instead of trying to force one fitting maybe past its max. At least that's my theory and I'm sticken' to it!

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 Posted: Wed Dec 5th, 2007 10:13 pm
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eleent
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Hello:  Glad it went well!  I'll agree with your theory, especially where brass fittings are involved.  When a string of fittings are to be tightened and the last fitting can be used to tighten all, it's nice because all the joints get tightened close to equally and you only need to find one spot to work from.  Also, for those interested in a pretty job, you only have wrench marks on one fitting :cool:    The things plumbers spend their days thinking about...

Yours,  Larry

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 Posted: Wed Oct 13th, 2010 07:52 am
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ken H
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Any idea if it is Ok to run csst along a foundation on the outside it then ducks under the house through a entry way

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 Posted: Thu Oct 14th, 2010 03:48 am
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eleent
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Hello:  I suppose it would be best to check in the instructions provided by the maker of your corrugated stainless steel tube (csst), but my take on it is that you don't run csst outdoors or anywhere it may be exposed to the elements. If you need to run it outside, perhaps a chase could be built around it.

Yours,  Larry

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