Many of these recommend use of a fuel filter. Are using one? Fuel Filter

First thing is making sure tank isn't over-filled. Outside away from spark or flame,crack the vent valve on tank. If liquid comes out,let it go until vapors come out then close vent. Now try the heater.

I took it to store and they said it weighed 44 lbs. now it weighs 36lbs. heater works as expected.

You are lucky the tank didn't blow the safety plug spraying liquid resulting in serious frost-bite and/or being ignited. The company that filled it is lucky to not be fined and facing lawsuit for filling a bottle without opd and overfilling to boot.

Is there a nearby big box store that has a propane tank exchange? I feel those tanks are properly filled.

Big box exchange tanks have 15 lbs and fill station tanks usually have 20lbs. Other than welding gas suppliers,noone is supposed to fill a tank unless it has opd valve that limits to 20lbs.

Its a local service station and they have 1000lb tank fill station. i had a 2nd tank filled a month ago and it felt heavy too. but we used that on a different style heater and it worked ok. he took coupler off fill hose and vented it thru the coupler. took 7 min? approx.

my tank is fairly new and has opd device.

my scale said 41lbs. their scale said 44lbs.

so, their scale is fudging?

I don't know why or how but the tank was overfilled. Tare = 17.5 Lbs + 20 Lbs propane = 37.5Lbs. All tanks have head space to allow expansion of contents as temperature rise causes pressure rise. The safety head space was filled on your tank and as I told you earlier, you are lucky to not had a serious problem.

Ha, i never weighed it after they vented it. maybe my scale would read 34 lbs now? well, my heater works. i might roll dice and do a tank exchange next time.