OSB 2 SERIES - Gauge Glass and Control Testing

20 Part Number 550-110-772/0816
OSB Series 2 Oil-Fired Steam Boilers – Boiler Manual
10 Service and maintenance continued
Gauge glass
Normal waterline is halfway up gauge glass. Clean when needed.
1. Close lower gauge cock.
2. Openpetcock.
3. Openlowergaugecockandallowasmallamountofwaterto
flush out through open pet cock.
4. Close pet cock.
5. Openlowergaugecock.
Boiler pressure must be low to eliminate potential
of severe burns.
 If gauge glass breaks, close both gauge cocks.
Replace gauge glass. Do not replace with thin glass
tubing. Failure to comply could cause severe per-
sonal injury, death or substantial property damage.
❏ Service. . . . . . . . . .
❏ Check/test. . . . . . . . . .
Boiler waterline
Normal waterline is halfway up gauge glass.
Limit controls
1. Inspect and test the boiler limit control.Verify operationby
turning control set point below boiler pressure. Boiler should
cycle off. Return dial to original setting.
❏ Check/test. . . . . . . . . .
Low water cutoffs
Probe-type low water cutoff (see below)
Clean and test probe-type low water cutoff for proper operation.
Remove, inspect and clean the low water cutoff at least annually
beforetesting.Refertolowwatercutoffmanufacturer’sinstructions
in envelope assembly provided with boiler.
1. Turn off power to boiler and wait 5 minutes.
2. Drain water to bottom of gauge glass.
3. Turn on power.
4. Set thermostat to call for heat. Red neon lamp on lower water
cutoff should light.
5. Wait 5 minutes. Boiler should not fire.
6. Refill boiler to correct waterline. Red lamp should go off.
7. Wait 5 minutes. Boiler should fire.
8. Return thermostat to normal setting.
Float-type low water cutoff (when provided by others
— see below)
Clean and test oat-type low water cutoff (when provided by
others)toclearoatchamberofsediment.
1. Openblowdownvalveatbottomcontrol.
2. Drain water into a bucket.
Scald potential. Boiler pressure must be low to avoid
the potential of severe burns from steam.
3. Check float-type low water cutoff for proper operation:
a. Turn operating control to call for heat.
b. Before water gets hot, drain to bottom of gauge glass.
Boiler should shut off after water level lowers a few inches.
c. Refill boiler to correct waterline. Boiler should come back on.