Watts AERCO Benchmark BMK5000 User Manual

Benchmark with Edge [I]: Operation-Maintenance Manual
SECTION 5 – SAFETY DEVICE TESTING
OMM-0145_D • GF-218 • 11/2/2020 Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST Page 74 of 213
5.2 LOW GAS PRESSURE TEST
Complete the instructions in Section 5.2.1 for BMK750 – 2500 units, or in Section 5.2.2 for
BMK3000 – 6000 units, which have different Low and High Gas Pressure switches.
5.2.1 Low Gas Pressure Test: BMK750 – 2500
To simulate a low gas pressure fault, refer to Figure 5-1a to 5-1c and perform the following
steps:
LOW Gas Pressure Test Instructions: BMK750 – 2500
1. Remove the front panel from the boiler to access the gas train components.
2. Close the leak detection ball valve located at the Low Gas Pressure switch.
3. Remove the 1/4" NPT plug from the ball valve at the Low Gas Pressure switch.
4. Install a 0 - 16” W.C. (0 – 4.0 kPa) manometer or gauge where the 1/4" plug was removed.
5. Slowly open the 1/4" ball valve near the Low Gas Pressure switch.
6. On the Controller, go to Main Menu → Diagnostics → Manual Mode.
7. Enable the Manual Mode parameter. The Comm LED will go off and the MANUAL LED will light.
8. Adjust the Air/Fuel Valve position between 25% and 30% using the + (Plus) and – (Minus) controls.
9. While the unit is firing, slowly close the external manual gas shut-off valve upstream of the unit (not
shown).
10. The unit should shut down and display a Fault Lockout - Gas Pressure Fault message at
approximately the pressure shown in Table 5-1 (the pressure setting of the Low Gas Pressure
switch):
TABLE 5-1: LOW Gas Pressure, ± 0.2” W.C. (± 50 Pa)
Benchmark Model
Natural Gas
Propane
BMK750/1000 FM & DBB Single-Fuel
2.6” W.C. (648 Pa)
7.5” W.C. (1,868 Pa)
BMK1500/2000 FM & DBB Single-Fuel
3.6” W.C. (897 Pa)
–
BMK1500/2000 Dual-Fuel
4.4” W.C. (1,096 Pa)
2.6” W.C. (648 Pa)
BMK1500/2000 DBB Dual-Fuel
2.6” W.C. (648 Pa)
2.6” W.C. (648 Pa)
BMK2500 FM & DBB Single-Fuel
3.6” W.C. (897 Pa)
–
BMK2500 Dual-Fuel
7.5” W.C. (1,868 Pa)
3.6” W.C. (897 Pa)
BMK2500 DBB Dual-Fuel
7.5” W.C. (1,868 Pa)
3.6” W.C. (897 Pa)
11. Close the ball valve near the Low Gas Pressure switch (opened in Step 5).
12. Fully open the external manual gas shut-off valve (not shown) and press the Controller’s CLEAR
button.
13. The fault message should clear, the FAULT indicator should go off, and the unit should restart.
14. Upon test completion, close the ball valve, remove the manometer and replace the 1/4" NPT plug
removed in step 3.

Watts AERCO Benchmark BMK5000 Specifications

General

Brand	Watts
Model	AERCO Benchmark BMK5000
Category	Boiler
Language	English