Thermo Pride MHA1-50N Installation And Service Manual page 26

All installations and services must be performed by qualified service personnel.
Piping from the natural gas meter to the furnace shall be in accordance with
requirements of the local utility. Piping from the propane tank to the furnace must
follow the recommendations of the gas supplier.
A readily accessible, design certified manual shut off valve with a non-
displaceable rotor member shall be installed within six feet of the gas equipment
it serves. A union or flanged connection shall be provided downstream from the
manual valve to permit removal of controls. A 1/8" N.P.T. plugged tapping is
provided at the inlet of the gas control for connection of a test gage to check gas
supply pressure to the furnace. Unions must be of a ground joint type or flanged-
jointed using a gasket resistant to LP gas. Pipe dope or sealant certified to be
resistant to the action of liquefied petroleum gases shall be used on all threaded
joints.
Left and Right Gas Supply Piping - This furnace is set up to accept either left or
right side gas piping using a street elbow and a straight pipe.
A sediment trap (drip leg) must be used on both propane and natural gas
installations, to trap oil, condensate and other impurities, which might otherwise
lodge in the gas, valve or plug the burner orifice. The sediment trap shall be
installed as close to the furnace inlet as possible. When there is excessive
condensation between the gas meter and the furnace, a sediment trap shall be
provided at the outlet of the gas meter. Failure to install a sediment trap may void
the limited warranty on the furnace, refer to Fig. 6.
If local codes permit the use of a flexible gas appliance connector, always use a
new listed connector. Do not use a connector, which has previously served
another gas appliance.
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