Is my Propane system clogged?

[Espee]

Issue:

Furnace flutter and large puff sound (with excessive spark ignition process), when furnace runs at same time as the water heater.

Notice significant increase in water heater burner performance at moment furnace shuts down... leading me to think there is insufficient gas volume?

Furnace still seems to have some degree of fluttering even when running on its own... (and kids want heat)

Now on third Marshall change over valve for the dual propane tank system.
Suburban model SF30F according to owner papers, but see no labeling on unit.
Only basic tools on board as camping out in the boonies...

Happy Holidays

[Chris_Bryant]

Keep in mind that the old Marshall Gas has been out of business for years now, and the company that now makes a similar looking regulator is no relation- even though they both are named Marshall- the present company is Marshall Excelsior, who has been producing LP equipment for decades.
The MEC (Marshall Excelsior) regulators are made in the US, the Marshall Gas regulators were made in Mexico. Most others are made in China, except the Cavagna, which are made in Italy. I have yet to have a failure of the MEC regulator.

[Old-Biscuit]

Espee wrote:
Thanks old biscuit
Figured out how to turn the adjustment on the regulator as had threaded hub design instead... all systems went south from moment I touched it, and couldn't get it back (verified junk regulator). Found a shop in town that stayed open till could make it there to get a replacement auto changeover. Load test with stove, water heater, and furnace together verifies problem solved. Every Marshall valve I tried on this rig has been junk.
Happy kids.
Thanks to all!

I am not a fan of Marshall Regulators.........

Thanks for the update

Nice to hear you have resolved your propane flow issues.

[Espee]

Thanks old biscuit
Figured out how to turn the adjustment on the regulator as had threaded hub design instead... all systems went south from moment I touched it, and couldn't get it back (verified junk regulator). Found a shop in town that stayed open till could make it there to get a replacement auto changeover. Load test with stove, water heater, and furnace together verifies problem solved. Every Marshall valve I tried on this rig has been junk.
Happy kids.
Thanks to all!

[Old-Biscuit]

MEXICOWANDERER wrote:
Is not the red reg color coded for 10lb operation?

RED is color coded for 'high pressure'
Can be anything above 10 psig

Most 5th wheels with separated cylinders (one in off side compartment) uses a 30# single stage HP regulator. They are RED.

[Espee]

pried dust cap off.... no adjustment on Marshall. 😞

edit-
oh yes it does. just not the conventional set screw...
will post follow up soon.

[MEXICOWANDERER]

Is not the red reg color coded for 10lb operation?

[Old-Biscuit]

Espee wrote:
yep, 5th wheel.
Both sides failing.
interesting, I figured the red valve fed straight through secondary regulator by looking at hose locations... but red color flags the old noggin now that you mention it.
Previous adventures where I had to replace changeover valve was when the off-side red regulator performed good, but changeover side failed. This time I am finding both sides to be problematic. Is the Marshall valve design a POS?

RED feeds to HP side of 2 stage then 2 stage feeds system (200# + to 30# then 2 stage 15# to 0.4# -----or 200# to 15# to 0.4#)

Marshall ;;;;;YES

Check out Cavagna LP Regulators

Problem when using either cylinder then issue is with the main reg (2 stage one)

S/B plastic cover center of 2nd stage (where output hose is)
Pry cover off...set screw (allen) or screw underneath
1 turn clockwise increases 1/2" WC (eye-ball adjustment!)

[Espee]

yep, 5th wheel.
Both sides failing.
interesting, I figured the red valve fed straight through secondary regulator by looking at hose locations... but red color flags the old noggin now that you mention it.
Previous adventures where I had to replace changeover valve was when the off-side red regulator performed good, but changeover side failed. This time I am finding both sides to be problematic. Is the Marshall valve design a POS?

[Old-Biscuit]

Cylinders on separate sides of 5th wheel??
Reason I ask and say 5th wheel is because of the 2 regulators

Do you have problems with both cylinders (Low pressure/fluttering etc)
OR when using cylinder with the RED regulator?

Red regulator is a single stage 30# reg used to drop cylinder pressure prior to feed it across front of rig to the 2 stage reg that feeds rv propane system.

The 2 stage reg is what maintains the 11" WC (0.4#)

IF issues are when using 'off side' cylinder (the one with Red reg) then swap cylinders (or just use the one at main reg (where change over valve is)

Red regulators routinely have been a problem

[Espee]

I am familiar with the turn it on real slow to prevent safety valve lock out... thnx
I have one auto changeover / w its own regulator for one tank, and second tank has its own regulator. I have turned set screw under the foil on BBQ regulators before, but these regulators do not have a set screw that I have figured any way to access...
Tanks are original 10 yr old 7 gal tanks.
Need the pressure check, but not gonna happen out here.

[MEXICOWANDERER]

Dint bring me glasses

[MEXICOWANDERER]

You can tell for sure by letting the hot water cool down, igniting the hot water heater, all tove burners, then the stove. A rude but effective load test.

[Itchey_Feet]

Is there a possibility that the valve in the propane bottle is not too blame, shut off bottles or bottle. remove line to bottle wait 30 seconds, replace line. Now open the valve on the bottle slowly (too fast will cause it to shut down part way) this may solve problem. Worth a try as it costs nothing. JMHO

[Old-Biscuit]

Your LP Regulator is NOT keeping up with demand

Needs to be able to supply 11" WC (0.4 psi) with at least 50% of gas appliance in service (should be able to do it will ALL in service)

You can adjust regulator but should use a manometer to set it. 5 1/2" Down ion one side and 5 1/2" Up on other side of manometer with ALL stove top burners ON HIGH
Remove cover plug on regulator and turn screw clockwise to increase output pressure