Installation, Operation & Maintenance Manual

44
TROUBLE SHOOTING – SERVICE TIPS
Problem Possible Cause Suggested Remedy
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 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, Install 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 Loop too high Repipe 2" to 4" (5cm to 10cm) Below Water Line
Uninsulated steam piping in boiler room, but
system piping insulated, causing vacuum Insulate Steam Pipes
condition on shut-down
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
Radiator traps failed open, allowing pressurization
Replace Traps or Trap Elements
of the returns
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
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
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
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
Water Hammer During Mid-Cycle
(Steam Boilers)
Water Hammer on Shut-Down
(Steam Boilers)
No Heat or Poor Heat
Distribution in the Building
(Steam Boilers)
System or Boiler Overfilling or Flooding
(Steam Boilers)
Excessive Water Level Bounce
(Steam Boilers)
Rapid Cycling
(Steam Boilers)
Hammering in the Boiler
(Steam Boilers)