U S Boiler Company ALTA-120 High Efficiency Condensing Boiler User Guide
- June 12, 2024
- U S Boiler Company
Table of Contents
ALTA
Model ALTA-120, ALTA-150, ALTA-180
High Efficiency Condensing Boiler
“Quick Start” Guide
ALTA-120 High Efficiency Condensing Boiler
IMPORTANT PRE-START CHECKS: Follow boiler fill (and other) instructions
in the ALTA Boiler Installation, Operating and Service instructions (I,O&S).
Inspect all water lines, gas lines, wiring, venting and associated
connections. Follow instructions to purge all air from the heat exchanger and
system piping with the hose provided. Do not install any boiler SKU ending
with “02” over 2,000 ft. (610m) altitude. (Example: ALTA-120-1G02). Only
boiler SKUs with -00 suffixes may be installed at altitudes between 2,000 ft.
(610m) and 10,100 ft. (3,079m) – Example: ALTA-120-1G00.
TIME-SAVING NOTE: Gas valve throttle screw and offset adjustments are not
required for start up. This boiler adapts to heating requirements with a self-
calibrating, “gas adaptive” control that monitors flame ionization to
automatically adjust the gas valve to a correct air-fuel ratio.
1. Start a call for central heat (CH) and observe the display.
NOTE: Boiler fires ten seconds after CH call.
If it does not light after two tries, the boiler will enter a “soft lockout”
for one hour. For fast reset:
- Interrupt power for three seconds
- Re-connect power and restart
- Press button to reset
- Watch for flame icon
2. Check gas pressure at valve
inlet test port. Verify that the inlet gas pressure is between the minimum and
maximum gas pressures shown on the rating plate when operating at maximum gas
input rate and when all gas appliances (including the boiler) are both on and
off.
GAS PRESSURE REQUIREMENTS (0-2,000 ft. only)
Max: 14.0 in.wc
Min: 2.5 in.wc (natural gas), 8.0 in.wc (L.P. gas)
Safety Check: Combustion
- Verify boiler is running over 50% firing rate
- Close boiler front door and wait five minutes
- Insert combustion analyzer probe into test port
- Measure carbon monoxide (CO)
- If CO is under 200ppm, combustion check is complete
- If CO exceeds 200ppm, follow troublehooting in I,O&S
- Replace test port cap into test port
Safety Check: Ignition Safety
Shut-Off
- When boiler is running, carefully unplug black electrode/ flame sensor wire at burner door using insulated pliers
- The burner should shut off immediately
- Reconnect black electrode/flame sensor wire
Quick Menu and Commands
See separate instruction card 110493-(XX) for these additional advanced menus:
Password, History, Diagnostic, Firing Rate, Setpoints, Pump, Lead/Lag
| Quick Menu| Default
---|---|---
| Boiler Switch: On/Off| On
| DHW Comfort Mode: On/Off*| Off
| DHW Setpoint:
(60°F to 140°F, 16°C to 60°C)| 120°F
49°C
| Central Heat 1 Setpoint:
(60°F to 190°F, 16°C to 88°C)| 180°F
83°C
| Central Heat 2 Setpoint:
(60°F to 190°F, 16°C to 88°C)| 180°F
83°C
*DHW comfort mode not available on heating-only boilers
| When not flashing or alternating, this temperature is:
• DHW outlet temperature during DHW priority
• Boiler supply temperature at all other times
---|---
| Visible when Central Heating demand is present
| Visible when DHW heating demand is present, icon will flash if DHW setpoint
is being adjusted
| Visible when burner is firing, icon adjacent to active priority
| Visible when Central Heating setpoint reset is enabled
| Visible when adjust mode is active, icon will flash if manual mode is
enabled
| Visible when manual reset lockout is active
Installation Tips
SELECT
vent length & diameter
Vent/Air Size-Inches (mm)| Minimum Equivalent Length-Feet (m)| Maximum
Equivalent Length-Feet (m)
---|---|---
2 (60)| 2.5 (0.76)| 70 (21.3)
3 (80)| 2.5 (0.76)| 135 (41.1)
Consult Operating and Service instructions (I,O&S) for approximate vent de-
rates
UNPACK
universal connector, lubricate heat exchanger gasket, install connector
SELECT
vent termination
For more vent termination options and complete venting information, see I,O&S
Instructions. 
NEAR BOILER PIPING:
CLOSELY SPACED TEES
NEAR
BOILER PIPING: PRIMARY/SECONDARY KIT
Part Number: 111577-01
WARNING
Improper installation, adjustment, alteration, service or maintenance can cause severe personal injury, death, or substantial property damage. For assistance or additional information, consult a qualified installer, service agency, or the gas supplier. This boiler requires a special venting system. Read Installation, Operating and Service Instructions carefully before installing.
111182-01