LP tank switchover

[Jeffmurkin]

I know I’ve seen this on the forum before but can’t find it again. We installed a new Onan LP 5500 last year. Ever since then our LP tanks will not switch over once one is empty. I have to manually switch the tanks from one side of the RV to the other. Switching the lever to the full tank won’t work. I recall seeing something about needing to replace something once you install an LP generator. Can someone please tell me what I need to do? Thanks in advance.

[travelin' texans]

Doubt that the generator install had anything to do with the problem, just the cheap Chinese regulator. Replace it with the Marshall brand & while you're at it replace the small one on the drivers side piping as well also with Marshall.

[XCMARK]

only a guess but the regulator on the pass side is a 30 PSI and the generator installer replaced it with a LOW psi regulator and tapped the generator fuel after that regulator.

[Nedshred]

I thought I saw somewhere that when installing an LP generator they were to somehow isolate the connection so the generator could not draw on the drivers side tank. I thought this was due to worry about lowering the pressure so much that your other gas appliances might flame out.

An older copy of an Onan 5500 installation manual said on page 4-5:

"Do not connect the genset fuel supply line to any appliance fuel supply line. The genset can draw fuel away from other appliances and cause a flame out. To prevent the possibility of flameout, the fuel supply system must be designed to deliver sufficient fuel for normal operation of the genset and other appliances at the expected temperature conditions. It may be necessary to use a separate fuel tank for the genset if sufficient fuel cannot be supplied with a single tank system.
WARNING The flameout of an unvented propane appliance can lead to explosive accumulations of gas inside the vehicle and the danger of severe personal injury or death. Do not connect the genset fuel supply line to any vehicle appliance supply line."

I don't know if this is an ONAN only requirement or whether it is required as well by the RVIA Code (NFPA 1192).

Anyhow I've seen on other forums where people specifically complain that the two bottles were no longer connected once a generator was installed. You might want to check if they have been disconnected from each other.