21 replies to this topic

[BrianT]

Hi guys,

Just a quickie question...

What kind of symptoms might be typical of a propane regulator going bad?

And I know everyone is going to suggest it,... I do not have a manometer at this time. I may be able to either make or get one before too much longer, but right now, I don't have one, nor am I close to anyone who I know that could check the pressure for me.

I have suspected that the pressure is a little low for well over a year. But I get a little sputtering of the furnace, especially when the tank level is getting low and before it switches to the other tank. (Automatic switch over, probably pretty standard with a twin 30# tank rv setup.) I've also seen it switch over even though one tank wasn't quite empty, close, but not quite. I have always noticed that the oven flame has never been as high as previous rvs, one of which is the exact same stove make/model.

For now, most stuff works. But sometimes, the furnace will go out and I can hear it relight. It may run for a while, or it may repeat the process intermittently. But it's typically either when it's very cold out or the tank level is very low. I understand what it's like when the tank runs out completely. Have had that happen numerous time and am familiar with how the various appliances react.

The only other thing I've notice is that the water heater doesn't run on gas. It tries to light, and if you're outside, you may even see a little flame. But it shuts itself down again before really getting the full burn process started. I've wondered if it's related.

Whatcha think? Possible regulator issue? Or am I on the wrong track?

Glad to hear your thoughts.

Brian

[Jack Mayer]

If this only happens when it is cold out it MAY be starvation. Especially prevalent when the tank volume in small trailer tanks is low. A high demand device like the heater wants a good amount of vapor. When it is cold out, the smaller tanks do not have enough volume to keep warm (especially when low), and that is compounded by the small surface area of the liquid. Thus they do not produce the amount of vaporization required to support large devices. Horizontal tanks have more surface area and tend to not exhibit this. And large tanks like 100lb tanks also do not exhibit it because they have enough volume in them to retain heat and cause better vaporization. If this only happens when it is cold then it may be this "problem".

[Bill B]

Brian - your a DIY kinda guy - 3+ ft of clear plastic tube, drop of food color, tape measure and some painters tape (the blue stuff). Your only looking at 11" column of water.

Tap into the low pressure side of the regulator, tee or maybe a stove burner jet, a loop down and back up (remember that the water you push down on the pressure side needs a go up on the air side, the math says 5.5" down and 5.5" up, + a comfort margin), and then the blue tape to a easy to read spot. Drop of food color (or something for a little color) into some water, pour x amount in the u-tube, 10" or so, (remember the 5.5" down and up) open the valve, measure.

Turn on the furnace, couple of burners, whatever, measure some more. It should stay at 11". If it is low or high, under the dust cover on front of the regulator is an adjustment. In for more pressure and out for less. Remember to check the pressure again after your done.

I have also had the mercapstan oil from larger tanks collect on the low points in the gas lines. Especially in a unit that has been sitting stationary for a while as a living structure.

[Mike57]

Hi guys,

Just a quickie question...

What kind of symptoms might be typical of a propane regulator going bad?

And I know everyone is going to suggest it,... I do not have a manometer at this time. I may be able to either make or get one before too much longer, but right now, I don't have one, nor am I close to anyone who I know that could check the pressure for me.

I have suspected that the pressure is a little low for well over a year. But I get a little sputtering of the furnace, especially when the tank level is getting low and before it switches to the other tank. (Automatic switch over, probably pretty standard with a twin 30# tank rv setup.) I've also seen it switch over even though one tank wasn't quite empty, close, but not quite. I have always noticed that the oven flame has never been as high as previous rvs, one of which is the exact same stove make/model.

For now, most stuff works. But sometimes, the furnace will go out and I can hear it relight. It may run for a while, or it may repeat the process intermittently. But it's typically either when it's very cold out or the tank level is very low. I understand what it's like when the tank runs out completely. Have had that happen numerous time and am familiar with how the various appliances react.

The only other thing I've notice is that the water heater doesn't run on gas. It tries to light, and if you're outside, you may even see a little flame. But it shuts itself down again before really getting the full burn process started. I've wondered if it's related.

Whatcha think? Possible regulator issue? Or am I on the wrong track?

Glad to hear your thoughts.

Brian

Most any company that is licensed to dispense propane and service equipment will be able to check it for you. On my last fill I asked what they would charge to check it. The answer was nothing if there were no problems.
The tech was very knowledgable and mentioned that he had attended a class in propane handling and was certified as such.
Without prompting from me he:

• Shut the tank output valve.
• Disconnected the output line from the regulator and inserted a test "T" to do the rest.
• Installed a Dwyer manometer, this is a standard that electronic manometers are calibrated against.
• Opened the tank output valve.
• Checked the max pressure from the regulator before shutoff (12"). Allowed it to sit for 5 minutes to check for internal leakage from the regulator (none).
• Shut the tank off, bled the line down to ~ 8" and waited for 10 minutes to check for system leaks (none).
• Checked actual pressure with gas in use (11", right on the money).
• When done he disconnected the test "T", reconnected the line to the regulator.
• Did a leak test with liquid leak test fluid (soapy water solution), all was good.

As mentioned, there was no charge other than for the propane that I just bought.
He has a customer out of me.

Good luck with yours.

[Bill B]

heck, I like Mike's answer even better. That would work for me.

[BrianT]

Thanks, guys. Just wanted to know what it might act like if pressure was low.

Jack, I'm reluctant to blame the tanks because they're the same tanks that work well on another nearly identical rv... the second rv that sits beside this one, same manufacturer, only a few months difference in production date, MANY parts completely interchangable. I haven't swapped the regulator, but have been tempted, just to see if there's any change. Probably easier to build the manometer.

Bill, thanks for the idea of tapping in, perhaps at a stove burner jet or someplace similar. Hadn't thought of that. Might be quite easy and handy.

Mike, would love to have someone closeby that I could get to do just what you mention. Not practical just now but may be in the next month or two. If I were a "good ol' boy", maybe. But I never learned the accent. And a northerner around here might as well be a person of color at a KKK rally. Sometimes, it's even a challenge to -get- propane.


Brian

[Rae]

My propane regulator told me it needed to be changed by whistling loudly whenever I operated a propane appliance.

[Cyberdave]

Don't forget stoves like our Magic Chef have a regulator. You will need to tap in prior to the stove regulator.

[Kirk]

You can get a hint by using your stove top, but it is only a hint. With a properly working regulator the burners should light and burn with a blue flame with some yellow just at the tips of the flames. If the pressure is low, there may be no yellow at all. Also, light one burner and turn it all of the way on. Then one at a time, light each of the burners and watch the height of the first burner as you turn on each additional one. If the pressure is low the first burner's flame will get shorter as you light more burners.

Again, that is not accurate but it is a very strong hint. Low pressure will usually also mean a lowered volume and that in turn means the lower flame at the stove.

[Mike57]

You can get a hint by using your stove top, but it is only a hint. With a properly working regulator the burners should light and burn with a blue flame with some yellow just at the tips of the flames. If the pressure is low, there may be no yellow at all. Also, light one burner and turn it all of the way on. Then one at a time, light each of the burners and watch the height of the first burner as you turn on each additional one. If the pressure is low the first burner's flame will get shorter as you light more burners.

Again, that is not accurate but it is a very strong hint. Low pressure will usually also mean a lowered volume and that in turn means the lower flame at the stove.

Following some of the above instructions for adjusting the regulator, this can be used if making a manometer seems too difficult.
http://www.dwyer-ins...ed/1213_cat.pdf
For the price it is a tool that any DIY guy should have in his tool box. Of course the plastic tubing and duct tape version will work just as well. Because of the design, these are the tools that are used as "primary" standards to adjust the more expensive electronic gauges. The only thing that can go wrong with them is to run out of water. Pretty easily fixed.

[Kirk]

Mike,

For no more often than one is used, I don't bother to carry one and because of the safety issue with propane, I do not work on the regulator myself. Remember that a malfunctioning propane appliance can kill you! If you must fool with the regulator, then invest in one but with the limited space we have and the rare need for one, I simply have it done by a propane dealer. I have found that if I have the pressure checked every couple of years or so, that is more than sufficient. In most cases, regulators last for a long time and when they fail it is usually quite apparent. They are designed to fail to the low pressure side for reasons of safety.

The price is reasonable and if you know what you are doing, I am sure that it could be done, but in all of my RV experience, I can only remember replacing pressure regulators two times and only once was the pressure in need of adjustment, when the regulator was good. For me, the space to carry that manometer is just not worth the trouble.

[BrianT]

Interesting how this thread came up again. I hadn't done a lot of thinking about it until just a few days ago. My furnace has taken to wanting to shut down and relighting more than is normal and I had wondered whether lack of gas pressure may be at the heart of it.

So, this morning I decided it was time to put together that manometer that we've all talked about. It wasn't hard at all. It was much more of a challenge finding something to actually connect where I had intended to connect it into the system.

Our rv has a BBQ grill quick connect that is only a few feet from the output of the trailer's gas regulator and a wonderful place to check pressure. I spent 2 hours running around trying to find a quick connect. Went to the local equipment rental place, every propane dealer in town, and the only plumbing supply place in town,... after I checked at Lowes, that is. After being stared at as though I had three heads for even asking for such a thing, I gave up and made something temporary for just this purpose out of a 3/8" air hose quick connect and lots of electrical tape. Don't worry, it's not going to be left on. It has a valve to shut it off, and it will be after I see if the pressure builds after being on for a while. I just did this to test, and for that, it did just fine.

It was interesting. When I first hooked up the manometer, it said 8.75" water column. Hmmm. No wonder the furnace sounded like it was starving for gas. When I started the furnace and the oven, it dropped to about 8".

So, I opened the cover on the regulator and adjusted a little at a time, turning up the pressure just a little, lighting the oven & running the furnace, then shutting them down again, checking the pressure, round in circles until I ended up with a pressure around 11" water column with nothing turned on. It drops to 10" or so with both the oven and furnace turned on.

Though the furnace does have a more "solid" sound to the flame, it's still not quite right. It seems to still want to shut down when it doesn't seem like it's supposed to, and then relight again. I'll keep an eye on that. When it started doing that kind of behavior before, I had to replace a control board. I do have another one but will monitor it for a bit before I do anything more.

The water heater still does not work on gas. I get flame but not the loud "woosh" that's normally associated with a water heater flame. It lights, but it's as though the flame doesn't even try to run through that tube but rather wants to burn back down around the valve, shutting off very quickly thereafter. I ran a flexible steel all the way through it and didn't see anything come through on the steel. Dunno. I don't have time to play with it anymore today.

Anyway, that's the skinny on what's here now and what I've done. I may keep the manometer hooked up but perhaps the ball valve at the BBQ connection turned off so that I can check it all again in a day or two just to see if the regulator is still putting out the proper 11". If not, I'll suspect that it may indeed have a problem. It seemed to perform well with today's tests, though.

I'm going to try to attach a couple of pictures. Nothing fancy, but you'll see a little more of what I did. I just marked off the board in 1/2" incriments and zip tied the clear tubing to it, along with a few dots of hot glue. The liquid was just plain ol' tap water with a few drops of red food coloring. The board was a scrap piece of 3/16" plywood that woulda gotten thrown away sooner or later. That's it.

Oh, and I didn't bother putting numbers on the board. I took a couple of clamps and clamped the board to the wall of the rv at one of the storage bay doors. Once it was level and secure, I put some water in until it lined up with one of the marks on the board. I didn't really much care which one. Once I had enough water to be right at one of the lines, I put a piece of black tape there to mark it as "zero". From there, it's just a matter of counting the lines. Maybe not quite as easy visually, but it worked for me.

Just updating.



Brian

Attached Files

•  manometer1.jpg   46.9K   15 downloads
•  manometer_connection.jpg   19.14K   13 downloads

Edited by BrianT, 31 March 2011 - 01:59 PM.

[Mike57]

Interesting how this thread came up again. I hadn't done a lot of thinking about it until just a few days ago. My furnace has taken to wanting to shut down and relighting more than is normal and I had wondered whether lack of gas pressure may be at the heart of it.

So, this morning I decided it was time to put together that manometer that we've all talked about. It wasn't hard at all. It was much more of a challenge finding something to actually connect where I had intended to connect it into the system.

Our rv has a BBQ grill quick connect that is only a few feet from the output of the trailer's gas regulator and a wonderful place to check pressure. I spent 2 hours running around trying to find a quick connect. Went to the local equipment rental place, every propane dealer in town, and the only plumbing supply place in town,... after I checked at Lowes, that is. After being stared at as though I had three heads for even asking for such a thing, I gave up and made something temporary for just this purpose out of a 3/8" air hose quick connect and lots of electrical tape. Don't worry, it's not going to be left on. It has a valve to shut it off, and it will be after I see if the pressure builds after being on for a while. I just did this to test, and for that, it did just fine.

It was interesting. When I first hooked up the manometer, it said 8.75" water column. Hmmm. No wonder the furnace sounded like it was starving for gas. When I started the furnace and the oven, it dropped to about 8".

So, I opened the cover on the regulator and adjusted a little at a time, turning up the pressure just a little, lighting the oven & running the furnace, then shutting them down again, checking the pressure, round in circles until I ended up with a pressure around 11" water column with nothing turned on. It drops to 10" or so with both the oven and furnace turned on.

Though the furnace does have a more "solid" sound to the flame, it's still not quite right. It seems to still want to shut down when it doesn't seem like it's supposed to, and then relight again. I'll keep an eye on that. When it started doing that kind of behavior before, I had to replace a control board. I do have another one but will monitor it for a bit before I do anything more.

The water heater still does not work on gas. I get flame but not the loud "woosh" that's normally associated with a water heater flame. It lights, but it's as though the flame doesn't even try to run through that tube but rather wants to burn back down around the valve, shutting off very quickly thereafter. I ran a flexible steel all the way through it and didn't see anything come through on the steel. Dunno. I don't have time to play with it anymore today.

Anyway, that's the skinny on what's here now and what I've done. I may keep the manometer hooked up but perhaps the ball valve at the BBQ connection turned off so that I can check it all again in a day or two just to see if the regulator is still putting out the proper 11". If not, I'll suspect that it may indeed have a problem. It seemed to perform well with today's tests, though.

I'm going to try to attach a couple of pictures. Nothing fancy, but you'll see a little more of what I did. I just marked off the board in 1/2" incriments and zip tied the clear tubing to it, along with a few dots of hot glue. The liquid was just plain ol' tap water with a few drops of red food coloring. The board was a scrap piece of 3/16" plywood that woulda gotten thrown away sooner or later. That's it.

Oh, and I didn't bother putting numbers on the board. I took a couple of clamps and clamped the board to the wall of the rv at one of the storage bay doors. Once it was level and secure, I put some water in until it lined up with one of the marks on the board. I didn't really much care which one. Once I had enough water to be right at one of the lines, I put a piece of black tape there to mark it as "zero". From there, it's just a matter of counting the lines. Maybe not quite as easy visually, but it worked for me.

Just updating.



Brian

You want 11" with something on. When shut down, the pressure will rise to ~12" or so and stop. That is a lock pressure and should go no higher, if it does, the regulator is leaking internally.. The last test is to shut the valve at the tank when you have 11-12" reading on the manometer and then open a valve somwhere and let the pressure drop to about 8". Shut the valve and wait 10 minutes. The pressure should not rise or fall. If it rises, you have an internal leak on the tank valve (it is not really shutting off). If it falls, you have a leak in the system somewhere. GET IT FIXED RIGHT AWAY. Check fittings with soapy solution etc. If that does not work, bring it to a tech and have it fixed. A propane leak is dangerous.

Good job with the manometer by the way!

[Kirk]

Mike,
It sounds as though you have more than the typical experience with propane issues? Did you at one time work in that sort of position? To me there is a great deal of similarity between working with propane and working with electricity. Neither are terribly difficult to do as long as you take the time to learn a few basic principles, but it is critical to do both the right way because of safety issues. Just because it isn't difficult to do does not mean that close is good enough!

Brian,
The furnace almost sounds like it might be cycling on the high limit device, rather than the thermostat. That is not a rare thing, so at least consider to make sure that it isn't the real problem. The limit device will open if the heat exchanger exceeds designed operation limits and that can be caused by things as simple as crushed ducting or blocked registers. Have you checked the thermostat when it turns off to see if it is calling for heat or not? That is a pretty easy thing to check and would tell you a great deal.

The fact that the water heater also has a problem would tend to make the propane supply suspect and low pressure can cause any number of problems with any gas appliance. Even so, the fact that the furnace improved but the water heater did not, makes it suspicious that you may have two problems.

Have you removed and cleaned the propane jet for the water heater? If you do this, do not use anything metal to put through the jet's opening but rather use wood or plastic. You can damage that opening with metal. Does your water heater have the adjustable air shutter (Atwood) or not (Suburban) as an incorrect air mix can cause this but it sounds more like too little gas to me. It may be that the propane valve is not opening properly?

[BrianT]

Thanks, Mike. I was just reading through one of the Atwood service manuals last night and they too said that I should be seing 11" with at least half of the gas appliances turned on. I didn't raise the pressure quite high enough.

Luckily, the manometer is still all hooked up so the procedure should be quite easy so long as it adjusts as it did yesterday.

When I had asjusted the regulator to where I did yesterday, I did turn the tanks off completely and just let the system set at 11" for about 15 minutes. The manometer didn't move so that seemed like a good indication that there are no serious leaks. I didn't take the pressure down to 8", though, to see if it would rise or fall. I'll do that this time and see what it does.

Thanks for your input.

Brian

[BrianT]

Mike,
It sounds as though you have more than the typical experience with propane issues? Did you at one time work in that sort of position? To me there is a great deal of similarity between working with propane and working with electricity. Neither are terribly difficult to do as long as you take the time to learn a few basic principles, but it is critical to do both the right way because of safety issues. Just because it isn't difficult to do does not mean that close is good enough!

Brian,
The furnace almost sounds like it might be cycling on the high limit device, rather than the thermostat. That is not a rare thing, so at least consider to make sure that it isn't the real problem. The limit device will open if the heat exchanger exceeds designed operation limits and that can be caused by things as simple as crushed ducting or blocked registers. Have you checked the thermostat when it turns off to see if it is calling for heat or not? That is a pretty easy thing to check and would tell you a great deal.

The fact that the water heater also has a problem would tend to make the propane supply suspect and low pressure can cause any number of problems with any gas appliance. Even so, the fact that the furnace improved but the water heater did not, makes it suspicious that you may have two problems.

Have you removed and cleaned the propane jet for the water heater? If you do this, do not use anything metal to put through the jet's opening but rather use wood or plastic. You can damage that opening with metal. Does your water heater have the adjustable air shutter (Atwood) or not (Suburban) as an incorrect air mix can cause this but it sounds more like too little gas to me. It may be that the propane valve is not opening properly?

Thanks for the input, Kirk.

On the furnace... It does sound a little like the high limit device but the timing doesn't usually make sense for that. I listened to it happen several times in the night last night. Furnace started, lit normally, burned for maybe 10 - 15 seconds, then the flame went out. Fan continued, then a few seconds later, furnace lights again, continuing to burn until what sounds like it has heated enough that the thermostat calls for shutdown. It didn't seem like the initial burn of 10 - 15 seconds was enough to get the to the high temps needed for the high temp limit to have been reached, but I could be wrong on that one. The interesting part to me was that it continued to burn normally after the restart cycle.

I have not taken the burner apart to see whether it may have some soot or carbon or other buildup from having run at such low pressures. My initial manometer reading yesterday was just below 8" W.C. with the furnace trying to run, and I know that's way below spec. (Manual calls for 10.5" to 11" W.C.) It has also been over a year since one of the circuit boards were replaced. I may have a look at the connections and make sure they're clean before getting too involved.

(Also, as Mike pointed out to me, I still have the pressure a little low so I intend to bump that up a tad higher today. It's probably running something near 10" W.C. right now.)

Interestingly, in the heat of yesterday afternoon, cooking a nice dinner for my wife and a good friend of ours that was coming to visit, I discovered that the air conditioner would no longer turn on. It's an Atwood thermostat that controls both the furnace and the AC. So there could be issues there, too. AARRGGHHH!!!! The web tangles deeper and deeper!! LOL!! So there could also be issues there that I haven't even begun to explore. (That's one of the reasons I was reading through an Atwood service manual last night. It's not that I read those for general pleasure. LOL!!!)

On the water heater, I have not taken anything apart, only observed that it appears to be clear of debris blocking the path of the flame through it. The water heater has never worked on gas since the day we bought the rv but has always worked fine on electric. So it has never been a real priority but still something that bugs me knowing it doesn't work right.

I would suppose that the next step on that one is to take the burner apart and give it a cleaning. It's possible there's something there that I can't see with it all put together that would be obvious with the assembly removed from the water heater. It does appear to be considerably easier to access than the furnace.

I am not familiar with the adjustable air shutter. Where would that be loacated? Is it down near the burner? Or up near the exhaust? or?? I didn't see anything that appeared to be adjustable but may not have been looking in the right place.

Thanks again for the insights.

Brian

[Kirk]

I suppose that your furnace problem could be in the thermostat. Like you, I very much doubt that the problem is high limit with such a short burn, then a normal one. It sounds more like it was turned off by that thermostat. Had it been a case of loosing the signal indicating the propane burning, I am pretty sure that it would have gone into lockout and so not relighted. Yours sounds exactly as it would if you turned the thermostat all of the way down, and then back up once more. I'd sure check the thermostat.

On the water heater, Atwood normally has an adjustable air shutter on the burner tube. It should be right at the point where the gas jet inserts into the tube. There will be a section which is slotted all around it just to the right of the jet. That section then is attached to the main burner tube with a single screw in a slotted hole. If you loosen that one screw it will allow you to move the slotted part to the right or left to open or close the air inlet to the burner. It is usually there that gas will try to burn if it does a flashback such as you described earlier.

If you send me a PM with your email address, I'll take a picture of mine to give a better description. I have a new water heater, but it is almost exactly the same as our 1998 model was in that area.

[Mike57]

Mike,
It sounds as though you have more than the typical experience with propane issues? Did you at one time work in that sort of position? To me there is a great deal of similarity between working with propane and working with electricity. Neither are terribly difficult to do as long as you take the time to learn a few basic principles, but it is critical to do both the right way because of safety issues. Just because it isn't difficult to do does not mean that close is good enough!

[Brian,
The furnace almost sounds like it might be cycling on the high limit device, rather than the thermostat. That is not a rare thing, so at least consider to make sure that it isn't the real problem. The limit device will open if the heat exchanger exceeds designed operation limits and that can be caused by things as simple as crushed ducting or blocked registers. Have you checked the thermostat when it turns off to see if it is calling for heat or not? That is a pretty easy thing to check and would tell you a great deal.

The fact that the water heater also has a problem would tend to make the propane supply suspect and low pressure can cause any number of problems with any gas appliance. Even so, the fact that the furnace improved but the water heater did not, makes it suspicious that you may have two problems.

Have you removed and cleaned the propane jet for the water heater? If you do this, do not use anything metal to put through the jet's opening but rather use wood or plastic. You can damage that opening with metal. Does your water heater have the adjustable air shutter (Atwood) or not (Suburban) as an incorrect air mix can cause this but it sounds more like too little gas to me. It may be that the propane valve is not opening properly?

Nope, not in the industry but I did spend last nite at ..... No, just a retired engineer with experience in electrical, hydraulic, pneumatic, chemical, design etc. etc.. I have also spent a LOT of time reading many of the great books published for the RV industry. Not all of them are right but enough are.
I agree, many similarities, Both propane an electrical can get you in trouble quickly, have to keep your head about you at all times and use common sense. No such thing as good enough.

Edited by Mike57, 01 April 2011 - 09:14 AM.

[Mike57]

Thanks, Mike. I was just reading through one of the Atwood service manuals last night and they too said that I should be seing 11" with at least half of the gas appliances turned on. I didn't raise the pressure quite high enough.

Luckily, the manometer is still all hooked up so the procedure should be quite easy so long as it adjusts as it did yesterday.

When I had asjusted the regulator to where I did yesterday, I did turn the tanks off completely and just let the system set at 11" for about 15 minutes. The manometer didn't move so that seemed like a good indication that there are no serious leaks. I didn't take the pressure down to 8", though, to see if it would rise or fall. I'll do that this time and see what it does.

Thanks for your input.

Brian

Great. I hope that was a help and all will work properly when you are done. I would keep a wary eye on the regulator, it is odd that it dropped pressure like that.
Good Luck.