P-K MACH
®
Gas Fired Boiler
Technical Service 1.877.728.5351
Revised: January 3, 2020
Released: January 3, 2020
Patterson-Kelley 2020
All Rights Reserved.
1004905981 P-K MACH C1500H-C4000 Installation and
Owners Manual (Rev F Jan-2020).docx
Page 44
Test the manual reset high temperature limit control as follows:
1. Cycle the boiler on by generating a heat request.
2. Allow the boiler to proceed through ignition until main flame is established.
3. Using a flathead screwdriver, turn down the setting on the manual reset high temperature limit
to its lowest value. Turning the screwdriver counter-clockwise decreases the temperature
setting.
4. When the outgoing supply water temperature exceeds the setting on the manual reset high
temperature limit, the main burner will shut off.
The NURO touchscreen will display 10009:
“High Temperature Limit”
. Return the system to normal
operation by readjusting the setting on the manual reset high temperature limit to its default setting,
press the reset button on the manual reset high temperature limit, and finally touch any prompts from
the NURO control.
3.10.4 Gas Pressure Switch Tests
Low Gas Pressure Switch
The b
oiler is furnished with a low gas pressure switch, installed near the boiler’s main gas
shutoff/control valve. The operation of this switch must be checked as follows:
1. Close the main gas cock (external to the boiler).
2. Cycle the boiler on by generating a heat request.
3. Allow the boiler to proceed through prepurge and attempt ignition.
When the main gas shutoff/control valve opens to attempt ignition, the low gas pressure switch will trip,
causing the NURO touchscreen to display 10012:
“Low Gas Limit”
. Even after re-opening the main
gas cock, 10012:
“Low Gas Limit”
will remain on the NURO display until the boiler is manually reset
by pressing “Reset Control”.
High Gas Pressure Switch
The boiler is furnished with a high gas pressure switch, installed near the boiler’s main gas
shutoff/control valve. The operation of this switch must be checked as follows:
1. Before starting the boiler, close the downstream gas coc
k located inside the boiler’s enclosure.
2. Cycle the boiler on by generating a heat request.
3. Allow the boiler to proceed through prepurge and attempt ignition.
When the main gas shutoff/control valve opens to attempt ignition, the high gas pressure switch will trip,
causing the NURO touchscreen to display 10011:
“High Gas Limit”
. Even after re-opening the
downstream gas cock inside the boiler, 10011:
“High Gas Limit”
will remain on the NURO display until
the boiler is manually reset by pressing “Reset Control”.
NOTE
Make sure to re-open the main gas cock (external to the boiler) after a successful test.
NOTE
Make sure to re-open the downstream gas cock (inside the boiler) after a successful test.
