The bleed valve should seal with just tight finger torque. At most a VERY light application of wrench.
Use soap bubbles to check for leaks. Particularly if old, the house regulator is an easy to replace suspect.
Until you are able to troubleshoot it, turn off the tank valve(s). Brett Wolfe
"If the tank is turned off how could propane leak out the house regulator? Could the "fill connection" be leaking? I thought that by closing the main valve that propane wouldn't leak out but it is still leaking?"
Propane tanks have a spring loaded "Acme" fill connector that is supposed to close back off when filler hose is unscrewed. Sometimes the spring loaded valve does not close all the way. The common way is to tap it with something, like a piece of wood, to get it to 'seat'.
The fix for this is to completely drain tank and replace fill valve assembly OR buy an 'emergency' adapter that screws on to the fill connector that has its own spring loaded closure. Future filling can be done with adapter in place. We carry one of these adapters, because if one fills their tank and the tank does not close off after removing the fill hose, there is a major problem that cannot be resolved at the fill station, maybe requiring calling the fire squad.
This is a link the adapter:
Hose adaptor with integral Back Check intended for attachment to filler valve. Should the fill valve on your tank fail, this fitting can be used to help seal the valve. It has similar differential drop during filling and doesn't need a manual vent. Short size allows container hood to be closed if adaptor remains on leaky filler valve.
To drain a propane tank to make a repair, can take many hours, since there is usually only a vapor outlet. Somewhere around the 1997 Foretravel build years, coaches had large propane tanks that have a unused "liquid' valve, probably originally purchased for coaches manufactured with propane generators. Our propane tank has a caped-off liquid valve that was used to drain our tank when we had a repair of a leaking shut-off valve. The propane shop actually recovered the drained propane into an empty tank and gave us credit for the propane.
We prefer to fill our propane tank at a propane depot, rather than a gas station, Flying J, repair shop etc, because the lack of expertise/experience of the technician can contribute to problems.
The 80% 'spit' valve can be replaced without draining the tank, because behind the spit valve is a very tiny hole, that when exposed while the spit valve is being replaced, does not let out a lot of propane gas. Barry Levitt 1997 U270 36"