Ultra Boiler Manual

Part number 550-100-440/0122
54
  
Legend — Figure 50
1 Ultra boiler
2 Indirect water heater (DHW), if used
3 Boiler relief valve (see page9 for piping details)
4 Relief valve discharge piping (see page9 for details)
5 DHW circulator (see page56 for suggested sizing)
6 Isolation valves
7 System circulator (see information above for wiring)
8 Diaphragm (or bladder) type expansion tank (see page56 for piping of
closed-type expansion tank, if used)
9 Air separator [with automatic air vent only on systems using diaphragm
(or bladder) type expansion tank]
10 Flow/check valves
11 Purge/drain valves
12 Boiler circulator
13 Zone valves, when used (zoning may also be done using manifold-mounted
valve actuators)
20 Make-up water supply
21 Primary/secondary connection (tees no more than 12 inches apart)
22 Optional high limit temperature control, set to protect radiant tubing
23 DHW supply/return
24 Strap system supply and return sensors to lines as shown, at least 6 pipe
diameters (but no more than 3 feet) from boiler connection tees.
25 Systems using high-head pumps may require a bypass pressure regulator
to prevent damage to control valves.
26 Temperature/Pressure gauge
27 DHW relief valve, if used
Items supplied with boiler
Items supplied by others
Figure 50 Typical radiant heating system piping plus optional
DHW

1. e Ultra boiler is ideal for use in radiant heating. e Ultra
boiler’s unique heat exchanger design allows it to work well
even in condensing mode. So there is no need to regulate boil-
er return water temperature in radiant heating applications.
2. Connect boiler to system as shown in Figure50 for typical
radiant heating applications. e primary/secondary piping
shown ensures the boiler loop will have sucient ow. Size the
system piping and circulator to provide the ow and pressure
drop needed for the radiant system.
Use at least the MINIMUM pipe size shown in Fig-
ure50 on all boiler loop piping (connecting boiler
to and from the primary/secondary connection,
item21). Use only primary/secondary piping
as shown.
Failure to follow these guidelines could
result in system problems.
3. Adding the recommended high limit control (Figure50,
item22) can help ensure supply water temperature will not
exceed the maximum allowable for the radiant system. Wire
this limit control in either the manual reset or automatic reset
external limit circuit of the U-Control.
4. When using a closed-type expansion tank, connect the
expansion tank and make-up water piping as shown in
Figure4,page11.
5. Connect DHW (domestic hot water) piping to indirect stor-
age water heater as shown.
By default, the U-Control Module turns o space
heating during DHW heating (if DHW input is
priority 1). e boiler circulator will turn o, pre-
venting hot water from circulating to the system
(optional timeout setting can be used to override).
e ow/check valve shown on the boiler outlet
piping prevents gravity circulation in the boiler
loop during DHW heating.
Overriding the Outdoor Reset function by setting control
to DHW mode when system is intended for space heating
may violate Section 303 of the 2007 Energy Act. See
page137 for compliance information and exemptions.
6. Controlling the circulators
a. e U-Control can control up to three circulators (boiler
circulator and two others). Refer to Field wiring, begin-
ning on page30, for instructions on wiring to circulators.
 (continued)
b. e factory default settings are: DHW circulator as Circu-
lator1, boiler circulator as Circulator2. See Field wiring
instructions, beginning on page30, for details.
MINIMUM
Boiler loop pipe size
Ultra-80, 105
Ultra-155, 230
Ultra-299, 399
1”
1¼”
1½”
See CAUTION at left.