15
Boilers may be factory packaged with tankless heater
coil
see figure below. Coil provides instantaneous heating
of water for domestic use if proper burner and water supply
line controls are used. Tankless coils are meant to provide
domestic hot water for intermittent draws, not continuous
flow.
NOTICE
Do not use tankless coil if your water is excessively
hard with lime or other deposits which will
accumulate inside the coil.
Factory Packaged with Tankless Heater Coil
h
Hydrolevel Control
Combination high limit / low limit control is located on
tankless coil cover plate.
Tempering valve (mixing valve) is also recommended as
shown in figure below. Flow restrictor may be required on
tankless coil inlet piping so flow rates are matched to boiler
heat input (see table).
SYSTEM PIPING
Tankless Coil Piping Arrangement
Figure 11 -Tankless Coil Piping Arrangement
DANGER
Scald, Burn Hazard! Temperatures exceeding 120°F
will cause severe burns or death. Use of water
tempering device or mixing valve may be required
by the Authority having jurisdiction, follow all codes
as required before leaving installation.
!
PN 240013023, Rev. B [12/31/2020]
Boiler
Model
Burner
Firing
Rate (gph)
Input
(MBH)
Tank less
Rating
(gpm)‡
UH3KWC0.80T
0.80
112
3.05
UH4KWC1.00T
1.00
140
3.25
UH4KWC1.25T
1.25
175
3.50
UH5KWC1.55T
1.55
217
3.80
‡ Gallons of water per minute heated from 40°F to 140°F with
200°F boiler water temperature, intermittent draw
