Desa VyS18NC - Manual (Page 14)

www.desatech.com 124452-01A 14
INSTALLATION
Continued
Figure 13 - Gas Connection
* Purchase the optional CSA design-certified
equipment shutoff valve from your dealer.
** Min. inlet pressure for purpose of input
adjustment.
Tee Cap Pipe
Joint
Nipple
3" Min.
Sediment Trap
Gas
Regulator
CSA Design-Certified
Equipment Shutoff Valve
With 1/8" NPT Tap*
Approved
Flexible
Gas Hose (if
allowed by
local codes)
Natural
From Gas Meter
(5" W.C.** to
10.5" W.C.
Pressure)
Propane/LP
From External
Regulator
(11" W.C.**
to 14" W.C.
Pressure
CHECKING GAS CONNECTIONS
WARNING: Test all gas piping
and connections, internal and
external to unit, for leaks after
installing or servicing. Correct
all leaks at once.
WARNING: Never use an
open flame to check for a leak.
Apply a commercial leak de-
tection solution to all joints.
Bubbles forming show a leak.
Correct all leaks at once.
CAUTION: For propane/LP
units, make sure external regula-
tor has been installed between
propane/LP supply and heater.
See guidelines under Connecting
to Gas Supply, page 13.
PRESSURE TESTING GAS SUPPLY
PIPING SYSTEM
Test Pressures In Excess Of 1/2 PSIG
(3.5 kPa)
1. Disconnect appliance with its appliance
main gas valve (control valve) and equip-
ment shutoff valve from gas supply piping.
Pressures in excess of 1/2 psig will dam-
age heater regulator.
2. Cap off open end of gas pipe where equip-
ment shutoff valve was connected.
3. Pressurize supply piping system by either
opening propane/LP supply tank valve
for propane/LP gas or opening main gas
valve located on or near gas meter for
natural gas or using compressed air.
4. Check all joints of gas supply piping system.
Apply a commercial leak detection solution
to all joints. Bubbles forming show a leak.
5. Correct all leaks at once.
6. Reconnect heater and equipment shutoff
valve to gas supply. Check reconnected
fittings for leaks.
Test Pressures Equal To or Less Than
1/2 PSIG (3.5 kPa)
1. Close equipment shutoff valve (see Fig-
ure 14).
2. Pressurize supply piping system by either
opening propane/LP supply tank valve
for propane/LP gas or opening main gas
valve located on or near gas meter for
natural gas or using compressed air.
Figure 14 - Equipment Shutoff Valve
Open
Closed
Equipment
Shutoff Valve
We recommend that you install sediment
trap in supply line as shown in Figure 13.
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 contami-
nants. 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
regulator. Hold gas regulator with
wrench when connecting it to gas
piping and/or fittings.