Automatic Changeover Regulator not changing over

[Chuck_S]

This is one of those times replacing the regulator is the simple solution. Buy it from Amazon and if it doesn't cure the problem just return it. $60 for an exact replacement on your front porch in 2 days.

You need LP (gas) Teflon tape. It's yellow and a standard Home Depot item.

-- Chuck

[Ham_Bone]

Thanks to those who chimed in on this thread. The comments are appreciated.

I did some more research and discovered that some pigtails, specifically those with the green knobs and sold by Camco, have a device located at the green knob that prevents a sudden large flow of gas in case of a broken gas line. LINK. It looks like mine is said Camco pigtail. I ordered a new pigtail and will replace the driver-side one. I'll post the results after I do this.

[dalford]

Originally Posted by nomad297

This is not true. There is no flow regulator/safety device in the tank/bottle, or associated with the OPD to limit flow — the device is in the regulator and sometimes in the ACME nut. If there was such a device in a propane tank, high-demand appliances/tools would not work. It is the job of the regulator to determine when the maximum flow for that particular regulator is being exceeded.

Bruce

I stand corrected then. I thought there was an emergency high flow cutoff that would stop propane from flowing if for some reason a propane hose was cut between the propane valve and the regulator. Must be wrong about that but I’m sure I’ve seen that in the thousands of posts about driving with the fridge on..

[2plus1]

OK, I'm confused, please explain the image below.

OPD Cylinder Valves
Two different types of overfill protection device equipped propane valvesOPD stands for "overfilling prevention device" or "overfill protection device" and is required on all 4 to 40 pound DOT cylinders in vapor service. The OPD valve is simply a protective device that, as the name implies, prevents overfilling of a propane cylinder. Before any propane cylinder (4 to 40#) can be filled with propane, the cylinder will be inspected to ensure that an OPD valve is installed on the tank. Propane companies can generally replace the non-compliant cylinder service valve with the required OPD valve quickly in order to bring it into compliance. Many consumers believe that the OPD valve was introduced to increase the profitability of propane dealers regarding cylinder filling. This statement could not be farther from the truth. When filling a propane bottle equipped with an OPD valve, the flow of gas stops immediately when the overfill protection mechanism closes. This is extremely hard on a propane dispensing pump resulting in more repairs and pump overhauls which can be quite expensive. The propane industry spends more money than they save as a result of the OPD valve requirement.

OPD Valve Information
Propane bottles equipped with overfill prevention valves are recognizable by the triangular hand wheel at the top of the valve itself. The hand wheel connecting to the valve stem is tamperproof and is not interchangeable with a cylinder not equipped with the overfill prevention safety mechanism. The OPD valve was not designed as a tool to let the bottle filler know when the bottle has reached its capacity. It was designed as a secondary safety mechanism. Bottles equipped with OPD valves are still to be filled by weight as required by law.

OPD Valve Operation
Propane OPD valves operate inside the bottle and are activated as the liquid propane in the cylinder rises to a level that pushes a float upward stopping the flow of gas into the bottle. This action is similar to that of a float valve in a toilet; once the water in the bowl rises to a certain level, the flow of water stops. The OPD valve is only actuated during the filling process, not during operation. In other words, inverting a cylinder will cause an OPD float to actuate but it will not stop the flow of gas out of the cylinder. Why is this important to know? Because the OPD valve is not designed to restrict flow out of the cylinder, it's only designed to stop flow into the cylinder during the filling process. OPD equipped propane cylinders will allow liquid propane into gas lines and hoses if tipped over or inverted. Overfill Prevention Devices are not a safety mechanism used or actuated during cylinder usage.

OPD valves are also designed to only allow propane into and out of the bottle if attached to the appropriate hose end connection. The threads on this type of connection are called ACME threads and are visible on the OPD valve at the point of connection. The ACME threads are easily identified by how much larger and farther apart they are as compared to normal pipe threads. OPD valves will not allow propane out of the bottle if it is not hooked up to anything. This is why turning (opening) an OPD handwheel on an unattached bottle does nothing in terms of letting propane out. Many people think that the bottle is empty but in fact, the cylinder needs to be hooked up to allow any gas out. Learn more about the Valve Open - No Propane issue that many users have with OPD equipped propane cylinders.

[nomad297]

Originally Posted by 2plus1

OK, I'm confused, please explain the image below.

The top valve is for small diameter bottles and the bottom valve is for larger diameter bottles.

Bruce

[Chuck_S]

Bottom valve has the DOT required Overfill Protection Device that's been mandatory for several years. Will have a 3-sided valve knob. LP outlets are not supposed to fill any other types.

https://www.youtube.com/watch?v=M1SBTOz5m8w

-- Chuck

[AFDON]

Originally Posted by 5picker

Does the gas flow from the full tank (drivers side) if you manually move the selector lever/knob once the auto-changeover fails?

If I remember right, there should be a small regulator in the drivers side bay, you don't want full tank pressure in that crossover hose (think accident and that hose cut!) They have a habit of failing, also that crossover hose could be failed on the inside. Flaking and jamming the bore so that no gas can pass. Disconnect (safely, no open flames or sparks close by) that hose at your main regulator and see if any gas flows when your drivers side tank is opened slowly. No reason to buy a new main regulator if its not bad.

Please post and let us know what you find out.

[5picker]

Originally Posted by Chuck_S

Bottom valve has the DOT required Overfill Protection Device that's been mandatory for several years. Will have a 3-sided valve knob. LP outlets are not supposed to fill any other types.
-- Chuck

Not only does the bottom valve in the photo have a OPD (float on a lever arm - think old style toilet float) but so does the top one.

The float on the top valve (think newer style toilet float) simply slides on the shaft vertically and performs the OPD function the same as the valve on the bottom.

[nomad297]

Originally Posted by 5picker

Not only does the bottom valve in the photo have a OPD (float on a lever arm - think old style toilet float) but so does the top one.

The float on the top valve (think newer style toilet float) simply slides on the shaft vertically and performs the OPD function the same as the valve on the bottom.

Exactly.

The easiest way to tell whether a valve is OPD or not is by the shape of the knob.

Both of those valves are OPD.

Bruce

[Bogieboy]

Originally Posted by 2plus1

OK, I'm confused, please explain the image below.

OPD Cylinder Valves

**Snip**

OPD valves are also designed to only allow propane into and out of the bottle if attached to the appropriate hose end connection. The threads on this type of connection are called ACME threads and are visible on the OPD valve at the point of connection. The ACME threads are easily identified by how much larger and farther apart they are as compared to normal pipe threads. OPD valves will not allow propane out of the bottle if it is not hooked up to anything. This is why turning (opening) an OPD handwheel on an unattached bottle does nothing in terms of letting propane out. Many people think that the bottle is empty but in fact, the cylinder needs to be hooked up to allow any gas out. Learn more about the Valve Open - No Propane issue that many users have with OPD equipped propane cylinders.

Originally Posted by nomad297

This is not true. There is no flow regulator/safety device in the tank/bottle, or associated with the OPD to limit flow — the device is in the regulator and sometimes in the ACME nut. If there was such a device in a propane tank, high-demand appliances/tools would not work. It is the job of the regulator to determine when the maximum flow for that particular regulator is being exceeded.

Bruce

@Nomad297, see the post i quoted... there is in fact a flow valve contained with the opd valve.

[nomad297]

Originally Posted by Bogieboy

@Nomad297, see the post i quoted... there is in fact a flow valve contained with the opd valve.

Please highlight or single-out the portion of what you quoted where it states this. Perhaps my reading comprehension isn’t up to par with yours.

Bruce

[wmtire]

I have posted this in other threads that explains things about where the low flow comes from in a cut line scenario

https://youtu.be/oaoI4frvhSQ

[5picker]

Originally Posted by wmtire

I have posted this in other threads that explains things about where the low flow comes from in a cut line scenario

https://youtu.be/oaoI4frvhSQ

My only criticism of that video is the information contained within, while very factual and good information, it is geared towards LP appliances and not the R/V world.

He makes mention several times the EFV (excess flow valve - he calls it a "slam" valve) is located in the regulator. It really is located in the threaded ACME nut. On most stand alone LP devices, the ACME nut IS directly attached to a regulator (with no pigtail in between the nut and the regulator) so if one needs to replace the ACME nut, (with EFV) you replace the regulator as well.

In the R/V world, the ACME nut has pigtails that ultimately do attach to the regulator but the regulator is often many inches or feet away from the actual tank. So, if someone in the R/V world perhaps heard in the video, the EFV is located in the regulator, they would overlook the ACME nut and misdiagnose.

The ACME nuts themselves have different flow rates depending on color as well. The light green connectors are rated for 200,000 Btu per hour. The black are rated for 70,000-100,000 Btu per hour. The dark green are rated for 450,000-500,000 Btu per hour. The Red connector is often used for high flow.

BTW... I agree with Bruce there is no flow regulator in the tank's OPD. I have several old style POL nut pigtails that will still screw inside a newer tank valve that have the outside ACME threads. I can screw one of these to a tank and open the valve and get full blast flow. We often use these pigtails to purge new tanks when filling for the 1st time.

[dedobias]

Originally Posted by dalford

It is actually in the tank. That is why you can’t open a valve and release the pressure of A tank not connected to the system. Also protects if you are in an accident and your propane line gets cut. It will stop propane from gushing from the tank unimpeded..

There is also a high flow safety valve in the regulator but your regulator seems to be working. You seem to be getting no gas from the tank.

NOT true, it is NOT 100% shut off. Look it up. Only Gas Stop is 100%.

[ewinterbee]

I do not want to hijack this thread, but have a related question that may be part of the OP problem. When my auto switch over reg switches from streetside tank to curbside (regulator side) the indicator turns red. I move the lever to curbside tank. It turns clear to indicate transfer has occured. When I remove the streetside tank to fill it, the residual propane in the crossover tube leaks out while pigtail is disconnected. Defective pigtail? When I reconnect filled tank, I have to switch regulator back to streetside and burn stove burners till they dont spit and sputter to get the air out of crossover tube. I was thinking of installing shutoff between crossover tube and pigtail for filling purposes? Could the OP crossover be full of air and needs "purged" after reconnecting? If it was, the appliances would be getting air, not LP after switchover? Or do I have something wrong in my system?

[5picker]

Originally Posted by ewinterbee

I do not want to hijack this thread, but have a related question that may be part of the OP problem. When my auto switch over reg switches from streetside tank to curbside (regulator side) the indicator turns red. I move the lever to curbside tank. It turns clear to indicate transfer has occured. When I remove the streetside tank to fill it, the residual propane in the crossover tube leaks out while pigtail is disconnected. Defective pigtail? When I reconnect filled tank, I have to switch regulator back to streetside and burn stove burners till they dont spit and sputter to get the air out of crossover tube. I was thinking of installing shutoff between crossover tube and pigtail for filling purposes? Could the OP crossover be full of air and needs "purged" after reconnecting? If it was, the appliances would be getting air, not LP after switchover? Or do I have something wrong in my system?

My last two regulators have small check valves where the pigtails screw into the regulator that are supposed to keep the LP from the opposite tank from bleeding out when you disconnect the ACME nut from the tank without having switched the selector lever/knob.

Ironically, both those regulators had one of the check valves go bad but mine stuck shut and would only allow a small amount of flow. Small enough that my furnace wouldn't light or all three burners on the stove at the same time.

You can buy just the check, which I did the first time. On the 2nd one, I simply replaced the regulator with a newer, high BTU unit.

The check valves are the brass fittings in the photo below.

[ewinterbee]

I think the check valves at my regulator are functioning. It appears to not get propane from the full tank, but rather the crossover tube appears to fill with air when the streetside tank is removed. Maybe I will install a check valve rather than shutoff at streetside pigtail. Thank you. I thought that might be the OP problem as well.

[nomad297]

Originally Posted by ewinterbee

I do not want to hijack this thread, but have a related question that may be part of the OP problem. When my auto switch over reg switches from streetside tank to curbside (regulator side) the indicator turns red. I move the lever to curbside tank. It turns clear to indicate transfer has occured. When I remove the streetside tank to fill it, the residual propane in the crossover tube leaks out while pigtail is disconnected. Defective pigtail? When I reconnect filled tank, I have to switch regulator back to streetside and burn stove burners till they dont spit and sputter to get the air out of crossover tube. I was thinking of installing shutoff between crossover tube and pigtail for filling purposes? Could the OP crossover be full of air and needs "purged" after reconnecting? If it was, the appliances would be getting air, not LP after switchover? Or do I have something wrong in my system?

I just changed out a regulator for a friend last weekend because the indicator and automatic switchover weren’t working. When I switched the lever over to the full tank and removed the empty tank, propane was bleeding through the regulator from the full tank and out of the pigtail for the tank I removed. I imagine this is why it wouldn’t automatically switch from one tank to the other.

It shouldn’t do this.

Bruce

[ewinterbee]

Maybe my explanation was misleading. My switchover works fine. It switches from the empty tank to the full tank no matter which one is full or empty. The indicator works fine. Turns red when a switchover occurs and goes clear after you flip lever. The problem I have is when I remove the streetside tank from the system, the crossover tube in my 5er fills with air (from the pigtail I assume). After I reconnect the streetside tank I have to switch the regulator back to that tank and burn all three stove burners till the flame sputtering stops (purging the air from the crossover tube). Then I switch regulator back to curbside tank and everything works fine until I remove streetside tank to fill it. The problem is the crossover tube fills with air without the tank on and if you dont purge it when you reinstall it, then when it switches, the appliances get air and shutdown. There propane odor when removed is very short lived (small amount of residual propane in tube?). I will take pictures this weekend of my driver side setup and start a new thread because something must be missing. I was just going to install a shutoff valve inline at streetside end of crossover tube so I could close it when I remove tank but would rather fix it correctly if I can figure out if something is missing. I will let this thread go back to OP. I thought the two might be related and hoped I was contributing something for OP to check. Seems something is not correct for this to occur. Wont be the first thing not 100% correct since we acquired this camper 5 years ago. I will gladly install a new regulator and 2 new pigtails if that is where the problem is.

[Ham_Bone]

Original OP here with a few updates. I changed the pigtail on the street-side. Problem still there. I changed the small, red, regulator in the street-side bay. Problem still there. I will replace the main, curb-side, auto-changeover regulator next.

"I told ya so's" are in order here from some in this thread.

Here is my lessons learned:

1) Apparently many techs say it's a good idea to change your main regulator out every 7 years or so. Mine is 7 years old. For that reason alone I should have disregarded what my troubleshooting efforts were telling me and just replaced it.

2) Because I was never able to see green flags from the street-side cylinder I assumed that the gas was not making it to the curb-side regulator (which is why I changed out the parts I did). Well guess what? That's one of the symptoms of a bad regulator.

Anyway, I'm out a few bucks and time, which I have an abundance of. I'll post back after I replace the regulator. Again, thanks for the replies.