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Detailed Service Procedures
Controls requiring annual service:
WATER RELIEF VALVE:
Check operation of water relief valve. Follow
instructions on label fastened to relief valve.
Scald potential. Do not check
operation of relief valve unless discharge piping
has been installed according to Boiler Manual.
If piping is not in place, a qualified service techni-
cian must properly install piping.
CIRCULATOR:
Follow oil-lubricating instructions on circulator.
Over-oiling will damage circulator.
Water-lubricated circulators do not need oiling.
General description of control operation:
AUTOMATIC AIR VENT:
Air is released when cap is unscrewed one turn.
If air vent leaks, remove small cap on top of vent,
push in stem of valve and then release to clean
valve seat. Screw cap completely on, then unscrew
one turn.
WATER RELIEF VALVE:
Provides discharge if boiler pressure exceeds 30
psig.
TEMPERATURE LIMIT CONTROL:
If high boiler water temperature occurs, control
shuts down burner, but allows circulator to run
as long as there is a call for heat. Limit should be
set higher than temperature needed for the sys-
tem. Maximum limit setting is 220
0
F.
CIRCULATOR:
Circulator provides forced water circulation
through boiler and piping system.
PRESSURE-TEMPERATURE GAUGE:
Provides reading of boiler pressure and tempera-
ture. Maximum boiler pressure is 50 psig, maxi-
mum water temperature is 220
0
F. Temperature
will vary according to system and daily heating de-
mands. The range will be from room temperature
up to limit control setting.
TANKLESS WATER HEATER:
Weil-McLain tankless heater ratings are based on
200
0
F boiler water temperature. To get rated out-
put, set tankless heater control to 200
0
F. Control
can be adjusted to meet system hot water re-
quirements.
EXPANSION TANK:
As water heats up, it expands. Tank provides a
place for increased water volume. May be open,
closed, or diaphragm-type. If relief valve opens
frequently, expansion tank may be water-logged.
Drain tank and re-establish proper air cushion.
1. Open-type - Located above highest radiator or
baseboard unit, usually in the attic or closet.
Has a gauge glass and overflow pipe to drain.
2. Closed-type - Welded gas tight and located
above boiler. Tank is partially filled with
water, leaving an air cushion for expansion.
3. Diaphragm-type - Welded gas tight with a
rubber diaphragm to separate air from water.
Tank must be located near boiler before inlet
to circulator.
An air vent must be installed in air vent
tapping on boiler when this type of tank is
used. This eliminates air in system.
Normal cold water fill pressure is 12 psig.
Tank pressure may be checked with an air
pressure gauge.
DANGER