Filter
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50
6
. Perform leakage test on gas valves (See Fig. 49.)
and procedure on page 45.
7. Test air switch in accordance with manufacturer’s
i
nstructions. (Turn panel switch to the “On” posi-
tion until blower is proven, then turn the switch to
“
Off.”
8. Inspect and clean burner using shop air.
As Required
1. Recondition or replace low water cut-off device (if
equipped).
2. Check drip leg and gas strainers.
3. Check flame failure detection system. (See “Post
Start-Up Check,” page 45.)
4. Check igniter. (Resistance reading should be 42-
70 ohms at ambient temperature).
5. Check flame signal strength. (Flame signal should
be greater than 1 microampere as measured at
the 2 pins on the upper left corner of the ignition
control).
6. Check firing rate control by checking the manifold
pressure. (See “Manifold Check” on page 44).
7. Test safety/safety relief valves in accordance with
ASME Heater and Pressure Vessel Code Section
IV.
Weekly
For low-pressure heaters, test low-water cut-off
device. (With heater in pre-purge, depress the low
water cut-off test button. Appliance should shut-off
and ignition fault light should come on. Depress reset
button on front of heater control panel to reset).
Monthly
1. Check flue, vent, stack, or outlet dampers.
2. Test blower air pressure. (See “Blower Check” on
page 43.)
3. Test high and low gas pressure interlocks (if
equipped). (See “Safety Inspection” on page 44.)
Semi-Annually
1. Recalibrate all indicating and recording gauges.
2. Check flame failure detection system components.
3. Check firing rate control by checking the manifold
pressure. (See “Manifold Check” on page 44.)
4. Check piping and wiring of all interlocks and shut-
off valves.
5. Check air filter and replace as necessary.
Annually
1. Test flame failure detection system and pilot turn-
down.
2. Test high limit and operating temperature. (See
“Post Start-Up Check,” page 45.)
3. Check flame sensor.
4. Conduct a combustion test at full fire. Carbon diox-
ide should be 8.5 to 9.0% at full fire for natural gas,
and between 9.5 to 10.0% for propane gas.
Carbon monoxide should be < 100 ppm.
5. Check valve coil for 60 cycle hum or buzz. Check
for leaks at all valve fittings using a soapy water
solution (while heater is operating). Test other
operating parts of all safety shut-off and control
valves and increase or decrease settings
(depending on the type of control) until the safety
circuit opens. Reset to original setting after each
device is tested.
Filter Maintenance
• Inspect quarterly
• Replace when tracking pressure exceeds -0.5 in.
WC at 100% fan speed, except for models 1104
and 2004, which need to be replaced when track-
ing pressure exceeds -0.7 in. WC at 100% fan
speed.
NOTE: Use Raypak replacement filters, kit number
012552F (12”X12”) for models 504-1104 and kit
number 012553F (16”X16”) for models 1504-2004.