Kitchen Gas Appliances - Water Heater Pilot Outage

I have a gas water heater that is not staying lit. The water heater has been unused (drained and disconnected) in a vacant house for almost two years. Before that, it was new and in service for only 1 year with no problems.

I am now trying to check the water heater to make sure it works so that I can sell the house. We are supposed to close tomorrow so I am in a real rush to have this completed. Let me get you up to speed on the developments to date.

When we got ready to hook up the gas, we noticed that a dirt dobber nest was in the very end of our copper tubing that hooks from the water heater to the tank. So we cleaned this out. Got it as clean as possible. Next we took a small LP gas tank (off of a grill) and a regulator (also off of a grill) and connected these to the copper tubing. We turned the gas on at the tank and then checked all of our connections all the way to the water heater for leaks. We had no leaks, so far so good. Then we go to light the pilot. We have to hold the pilot button down for approximately 5 minutes or so to purge the line and actually get gas at the water heater. We light the pilot and then turn the gas on. Everything is going great. We watch it for several minutes. It stays lit the entire time. We close the doors on the water heater and then notice the gas and pilot have gone out. We light it back and watch it again and everything is great. We close the doors again and it burns for a few minutes and then goes out. We go through this process several more times. The gas and pilot only went out one time with the doors open. The rest of the time it was shortly after the doors closed. We finally lit it and just left the doors open for a while and it was fine for about twenty minutes (as long as the doors are open). It seemed to heat up very slowly. We did check the thermostat and the gas would go off and leave the pilot light on. We checked the water at the faucet and it was only lukewarm after what seemed like forever.

I don't know what direction I need to go. Here are some questions that I have.

Can we even use that small gas grill tank and regulator or is the pressure too low? Should I get the gas company to bring a larger tank out? I have not worked with a gas water heater much as far as problems go, so I have no idea where to start. I am at the point where I am trying to decide if I need to have someone go look at it. I just don't want to do that if there is some easy fix. Something that will be obvious to someone else that they can easily point out for me.

How long should the initial heat up take? It is a forty gallon heater. It just seemed to take a long time.

Any direction that you can give me will be greatly appreciated.

Welcome DWall to my Gas Appliances topic.

I cannot say for sure what effect, if any, the usage of a BBQ propane tanks regulator and or the pressure it supplies or the volume of gas it can supply has on the water heater. Just too many variables to assume without on site inspection.

Very ggod chance and possibility the pilot assembly and or pilot orifice is restricted with dust, lint and or a spider and or spider web. Same may apply to the burners orifice and or burner.

To determine this, it takes a trained eye on the effects with the pilot and burner in full operation. Also a visual inspection while the heater si in operation, so the flame sizes and charactoristics can be observed.

The pilot flame must be all blue as well as the burner flame. If there is yellow anywhere in either or both of them, that is an indication of a restriction which must be cleared out.

Removal of the entire burner assembly is required in most cases. The pilot assemble is a part of the assembly. Removal of the assembly removes both. Both have to be disasembled, cleaned out as needed, reasembled and reinstalled exactly as found.

Also possible only the thermocouple is weak. Replacing it is required but may or may not resolve the problem if any of the other conditions exists.

The thermocouple is the element that the pilot flame heats. This element is located in the pilot assembly where you lite the pilot. The other end screws into the gas valve.

The thermocouple end that screws into the gas valve is where the magneto head is located. This part, on many gas valves, is removeable and can be replaced, if needed.

The thermocouple is the most likely part to cause the problem you described. It is also one of the easiest and least expensive parts to replace.

If there is presently an all BLUE pilot flame at the pilot assembly, replace the thermocouple with a new one first and retry lighting the pilot. The only differences between T-couples is their length. Be sure to purchase one of the same length as the existing one.

Replacements are available at all hardware stores. The package contains a various assortment of holding clips and complete installation instructions.

The magneto is not likely the problem. However, if you correctly install a new T-couple and the water heaters pilot still does not remain on, suspect the magneto head as the second most likely defective part.

This magneto head screws directly into the gas valve. This item is available at the local appliance retail parts store and some selected hardware stores. Closely follow all enclosed installation instructions and do not over tighten it upon installation.

Be advise that other condition may apply. A lack of air into the firebox may also be all or part of the problem. Check the air intake holes under the base of the water heaters tank.

Leaving the covers off does provide air for combustion but does not solve the problem. Smothering flames will continue since the flames are shaped by the air flow into the tank.

Air must enter from below the inner plate and from around it's completed circumference for completed burning of the fuel.

A restricted flue pipe inside the water heaters tank is yet another possiblity. Smothering flames in the firebox will result. All other conditions described above must be diagnosed and solved by a professional plumber and or gas company appliance service rep.

Be sure the appliance is turned off before attempting any repairs. Always check for gas leaks whenever a repair includes any connection of a gas part, gas line or tubing or gas supply.

If you need further assistance, use the REPLY button to add any additional information or questions, etc. Using this method also moves the topic back up to the top of the list automatically.

Read the prior asked questions in this forum on this topic of water heaters and the replies offered. In them you'll find additional helpful information.

Regards & Good Luck. Sharp Advice
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Thanks for the advice! I also called the manufacturer and they gave me some guidance on the gas pressure required. They said it should be 11" - 13" WC. So I will check it out. I will also check some of the more noticeable things such as the flue and the air intake. Hopefully this will work. If not, I will have someone come out and service the water heater.

Thanks again.

Well, I have purchased an approved regulator for my water heater gas line. I installed it and checked for leaks. I also checked the air intake at the bottom of the water heater. No problems. I checked the vent inside the water heater and the vent going through the roof. No obstructions at all. So I light my pilot and close the doors. After burning for a few minutes, the burner and pilot still go out. I have discovered that there is a ping or a click right before the flames go out. I think the valve is shutting off the gas.

I inspected my gas water heater at my home and compared it to the one I am trying to fix. The pilot flame, on the one at my home, is much bigger than the one I am trying to repair. The pilot flame, on the one at my home, stays the same size regardless if the burner is burning or not. And the thermocouple if always in the pilot flame. The pilot flame, on the one I am repairing, engulfs the thermocouple as long as the burner is not burning. If the burner kicks on, the pilot flame gets very low and the thermocouple is no longer in the pilot flame. Why would the pilot flame burn so much lower with the burner on? Should I just adjust my thermocouple tip so that it is closer to the pilot flame? Or is this a problem with the gas controls? Am I right in assuming that the valve is shutting off the gas?

Your input is greatly appreciated.

DWall

Well, I think I have solved the problem.

I purchased a new thermocouple and got ready to install it. Before installing it, I thought I would light the pilot again to see what happens. It goes out (as usual) after a few minutes. I then decide to adjust the existing thermocouple so that it stays in contact with the pilot at all times (even when the pilot burns low). After this adjustment, the pilot stayed lit as long as we had time to watch it. We let it burn for about 2-1/2 hours. It seemed to be heating the water up. Although it took a while. It was pretty warm after the 2-1/2 hours, but still not hot to the touch. I assume that this amount of time for an initial heat up is normal. I also assume that the pilot burning lower, while the burner is on, is normal.

If any of this doesn't sound normal, please let me know.

Thanks for the advice.
DWall

Hello: DWall

Properly working water heaters can make a full recovery in that period of time under normal operating conditions. Based upon your description pf the water temp out of the tank, such is not the case.

Still a problem. If the pilot flame decreases in size when the burner turns on and the recovery is not up to full temp after 2 and a 1/2 hours, indicates a problem of some type still exists.

Usually means incoming gas volume supply to the control is lacking. Prseeure might be fine but will drop on demand as well as the volume of gas.

If the supply and pressure is okay to the control, than the problem description indicates either a control problem, usually the internal non repairable regulator inside the control or there is a restriction within the control or the pilot orifice and or burner orifice is restricted.

That's leaves plenty of possibilities. The intent here is not to suggest replacing the control if other possible problems still exist. Doing so would not correct the problem. Simply waste your time and your money on unneeded parts.

The tiny click heard is the solenoid dropping down when the magneto losses the current produced by the T-Couple or the current the T-Couple produces deminishes as the T-Copule gets lets heat from the pilot flame as it decreases in size.

All the above are required interactions that effect other parts and systems. All must be in proper working order or the water heater does not work or does not work well. Determining the exact cause requires a step by step process. One step at a time.

Your pilot could be getting weak because you are not feeding the heater enough dinosaurs. Are you still running the water heater off a small LP tank? It takes a certain amount of liquid propane to boil/vaporize to make enough propane gas to run your water heater. Most high btu items (furnaces, construction heaters...) state that they need at least a 100 gallon tank, for example.

Thanks for the great info.

We are still running the water heater of a small (20 lb.) tank. The purpose for this was to show that water heater did work. We have not had our walk through with our buyer yet. We have not let it run continuously either. Just enough for us to see that the pilot was going to stay on and the water was going to get warm. Our thoughts were to go and light the pilot the day before the walk through and give it plenty of time to heat up. Then, change the small tank out the next day (before the walk through) to make sure that our propane doesn't run out.

It sounds like we do need a bigger tank to allow the water heater to run more efficiently. Our buyer has stated that they will set up a large tank as soon as the deal is done. We started to do this, but no one (gas company) could set a tank soon enough for our walk through.

Will the water continue to heat up with a small tank? We ran it for 2-1/2 hours and it continually got hotter over that time frame. If this small tank will work for our purpose, we would like to use it even though it may not be as efficient.

If you are concerned about the heaters performance and have the fittings you can plumb two or three of the 20 lb. tanks together. I think the one tank and reduced btu output will eventually get the tank heated up, it will just take longer. Also, since the output of propane gas depends on the amount of liquid propane in the tank... the more you use the less it will produce. Cold temperatures will also reduce the amount of propane gas your tank can produce (at -43 f it remains a liquid and does not vaporize).

At the minimum you may want a full and warm tank for your walk through so the flame appears more vigorous.