Desa VYM27NR/PR - Manual (Page 11)

108382-01C
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Installation Items Needed
Before installing heater, make sure you have the items listed below.
• external regulator (for propane/LP units only, supplied by in-
staller)
• piping (check local codes)
• sealant (resistant to propane/LP gas)
• equipment shutoff valve *
• test gauge connection *
• sediment trap
• tee joint
• pipe wrench
* A CSA design-certified equipment shutoff valve with 1/8" NPT
tap is an acceptable alternative to test gauge connection. Purchase
the optional CSA design-certified equipment shutoff valve from
your dealer. See Accessories, page 24.
For propane/LP units, the installer must supply an external regula-
tor. The external regulator will reduce incoming gas pressure. You
must reduce incoming gas pressure to between 11 and 14 inches of
water. If you do not reduce incoming gas pressure, heater regulator
damage could occur. Install external regulator with the vent point-
ing down as shown in Figure 13. Pointing the vent down protects it
from freezing rain or sleet.
INSTALLATION
Continued
Installation must include an equipment shutoff valve, union, and
plugged 1/8" NPT tap. Locate NPT tap within reach for test gauge hook
up. NPT tap must be upstream from heater (see Figure 14).
IMPORTANT: Install equipment shutoff valve in an accessible
location. The equipment shutoff valve is for turning on or shutting
off the gas to the appliance.
Check your building codes for any special requirements for locating
equipment shutoff valve to fireplaces.
Apply pipe joint sealant lightly to male NPT threads. This will
prevent excess sealant from going into pipe. Excess sealant in pipe
could result in clogged heater valves.
CAUTION: Use only new, black iron or steel pipe.
Internally-tinned copper tubing may be used in certain
areas. Check your local codes. Use pipe of 1/2" diam-
eter or greater to allow proper gas volume to heater. If
pipe is too small, undue loss of volume will occur.
WARNING: Use pipe joint sealant that is resistant
to liquid petroleum (LP) gas.
Figure 13 - External Regulator With Vent Pointing Down (pro-
pane/LP gas only)
Propane/LP
Supply Tank
External
Regulator
Vent
Pointing
Down
We recommend that you install sediment trap in supply line as
shown in Figure 14. Locate sediment trap where it is within reach for
cleaning. Install in piping system between fuel supply and heater.
Locate sediment trap where trapped matter is not likely to freeze. A
sediment trap traps moisture and contaminants. This keeps them
from going into heater controls. If sediment trap is not installed or
is installed wrong, heater may not run properly.
CAUTION: Avoid damage to control. Hold fitting
with wrench when connecting it to gas piping and/or
fittings.
* Purchase the optional CSA design-certified equipment shutoff
valve from your dealer. See Accessories, page 24.
** Minimum inlet pressure for purpose of input adjustment.
Figure 14 - Gas Connection
Gas Control
3" Minimum
CSA Design-
Certified Equipment
Shutoff Valve With
1/8" NPT Tap*
Approved Flexible
Gas Hose (if allowed
by local codes)
Tee
Joint
Pipe
Nipple
Cap
Sediment
Trap
Natural Gas
From Gas Meter
(5" W.C.** to 10.5"
W.C. Pressure)
Propane/LP Gas
From External
Regulator (11"
W.C.** to 14" W.C.
Pressure)
INSTALLATION
Connecting To Gas Supply (Cont.)