PB Heat 211A - Manual (Page 49)

47
TROUBLESHOOTING – SERVICE TIPS
Problem Possible Cause Suggested Remedy
Main Gas Valve Opens
Manual Valve Closed at Gas Train Open Valve
But No Gas Flows
Manual Valve Closed at Meter Open Valve
Test Firing Valve Closed (if Provided) Open Valve
Sags in Steam Piping or not enough Pitch Correct Piping Condition
Concentric reducers causing condensate pooling Correct Piping
Drip trap failed closed Replace Trap or Trap Element
Water Hammer On Start-Up
Dry returns wetted due to new boiler water line
Correct Piping or Install Feed System and Traps
higher than old boiler
No drip line on the back side of a back-pitched
Install Drip Line and Trap
motorized valve
Clogged returns on gravity system Clean or Re-Pipe Return Line(s)
Incorrect near-boiler piping causing wet steam
Correct Piping per Manual
to system
Trap failed open, allowing steam to enter returns Replace Trap or Trap Element
{Radiator Hammer} Large radiator may be
Use smaller Air Vent or Use Two Small Vents in
vented too quickly
Place of One Large Vent, One Mounted Higher
than the Other
Long nipple at Hartford Loop Replace with Close Nipple
Water Hammer During Mid-Cycle Water leg or back slope in return line to receiver
Correct Piping
tank, causing water pocketing
Trap installed at receiver tank, causing water Remove Trap at Tank, Installing Drip Traps and
trapping in return Radiator Traps where Required
Boiler feed pump or condensate pump feed rate
Throttle Flow Rate
too fast, causing spraying into equalizer
No drip on the inlet side of a forward pitched
Add Drip Line and Trap
motorized valve
Uninsulated steam piping, causing excessive
Insulate Steam Pipes
condensate loads
Close nipple on Hartford too high Repipe 2" to 4" (5cm to 10cm) Below Water Line
Water Hammer on Shut-Down
Uninsulated steam piping in boiler room, but
system piping insulated, causing vacuum
Insulate Steam Pipes
condition on shut-down
Hammering in the Boiler
Poor circulation in the boiler due to sludge
Clean and Blowdown the Boiler
accumulation
Main vents not working
Replace Main Vents, Repiping away from End
of Lines if Needed
Drip Traps failed closed Replace Traps or Trap Elements
No Heat or Poor Heat Distribution
Radiator traps failed open, allowing pressurization
Replace Traps or Trap Elements
of the returns
in the Building
Water legs or back slope in return lines to receiver
Correct Piping
tank, preventing air from venting out receiver vent
Boiler pressure too high, causing air vents to lock
Reduce Operating Pressure
up or blowing water loop seals
New boiler water content smaller than old boiler
Install Boiler Feed System with Receiver Tank
Large enough for Condensate
Boiler water feed rate or pump rate too fast
System or Boiler Overfilling or Flooding causing water level to collapse (due to collapse of Reduce Feed Rate
steam bubbles in boiler water)
Foaming, priming or surging due to poor
Clean the Boiler
water quality
Poor water quality, causing foaming and surging Clean the Boiler
Excessive Water Level Bounce
Incorrect near-boiler piping, such as undersized
Pipe per Manual
or incorrectly placed risers
Boiler water feed rate or pump rate too fast Reduce Feed Rate
Air vents or traps not venting air, preventing
steam from getting to radiation and pressurizing
Replace Vents or Traps
Rapid Cycling
the air pocket
Pressure differential on pressure control too close Adjust Control Differential
Nuisance outages of water level control due to
See Excessive Water Level Bounce Above
boiler water level bounce