Part number 550-100-131/0120
– 39 –
®
gas
-
fired
water
boiler
— 220/299/300/399
Boiler Manual
Use two wrenches when tightening water piping
at boiler, using one of the wrenches to prevent
the boiler interior piping from turning. Failure to
support the boiler piping connections to prevent
them from turning could cause damage to boiler
components.
General piping information
Additional controls, if required
The control uses temperature sensors to pro-
vide both high limit protection and modulating
temperature control. The control module also
provides low water protection by sensing the
temperature of the heat exchanger.
The control’s
high limit function requires manual reset
.
Some codes/jurisdictions may require additional
external controls for high limit and/or low water
cutoff protection.
Additional limit controls
Following standard industry practices, if installation is to com-
ply with ASME or Canadian requirements, an additional high
temperature limit may be needed. Consult local requirements
for other codes/standards to determine if needed.
1. Install a manual reset high temperature limit constructed to
prevent a temperature setting above 200°F in system supply
piping between boiler and isolation valve. (Note that the
Control operating limit function shuts the boiler down at
195°F, or lower if set to a lower value.)
Multi-temperature systems
— If the heat-
ing system includes circuits that require lower
temperature water (radiant slab circuits, for
example) as well as higher temperature circuits,
it is recommended to protect low-temperature
circuits with limit controls that are wired to a
Control external limit circuit terminals.
2. See instructions beginning on page 52 for wiring informa-
tion.
3. When using a manual reset limit control or wiring in the
manual reset circuit, preferably set Max. Boiler Temperature
or Supply Max. at least 20°F less than the external manual
reset limit (i.e., set control no higher than 180°F for a 200°F
external limit, for example).
Separate low water cutoff
1. A separate low water cutoff device is recommended when
the boiler is installed above piping level, and may be
required by certain state or local codes or insurance com-
panies. Consult local requirements to determine. See the
NOTICE above regarding the inherent protection provided
by the Control module. Low water cutoff is standard equip-
ment with the
Evergreen
®
boilers.
2. The Control’s integral protection is accepted in many
jurisdictions as meeting the requirement for low water
protection. See page 56 for details.
3. When required, use a low water cutoff designed for water
installations. Electrode probe-type is recommended.
See Replacement parts section at the end of this manual for
the Weil-McLain low water cut-off kit.
4. Purchase low water cutoff and install in a tee in the supply
piping above boiler.
5. See field wiring instructions beginning on page 52 for wiring
additional limit controls.
Backflow preventer
Use backflow preventer in the cold water supply piping if required
by local codes.
Boiler loop pipe sizing
(Baseboard, convectors or cast iron radiators ONLY)
For residential space heating applications (other than radiant
heating or unit heaters) ONLY, you can use the sizing suggestions
in Figure 47.
Figure 47
Suggested pipe sizing for boiler loop
Use
at least
the
MINIMUM
pipe size shown in
Figure 47 on all boiler loop piping (connecting
boiler to and from the primary/secondary
connection).
Use only primary/secondary
piping as shown.
Failure to follow these
guidelines could result in system problems.
Install water piping
Figure 48
Pressure drop through the
Evergreen
®
heat
exchanger
EVG 220
EVG 299/300
EVG 399
Flow
Rate
(GPM)
Head
Loss
(ft. w.c.)
∆
T
(°F)
Flow
Rate
(GPM)
Head
Loss
(ft. w.c.)
∆
T
(°F)
Flow
Rate
(GPM)
Head
Loss
(ft. w.c.)
∆
T
(°F)
10**
0.0
45
13**
0.0
45
18**
0.0
45
12
0.0
37
18
0.3
33
24
0.3
33
14
0.1
31
22*
0.6
27
28*
0.7
29
16
0.2
28
28
1.2
21
32
1.1
25
18*
0.2
24
32
1.7
19
36
1.6
22
20
0.3
22
–
–
–
40
2.2
20
22
0.5
20
–
–
–
–
–
–
* Suggested design flow rates based on a 25
°
F (EVG
220/299/300) and 30
°
F (EVG 399) temp rise through the
boiler.
** Minimum flow rates.
Model
Boiler loop
EVG 220
1¼” or larger
EVG 299, 300 or 399
1½” or larger
Recommendations are based on a 25
°
F (EVG 220/299/300)
and 30
°
F (EVG 399) temp rise through the boiler.
