Installation guide

Tankless Coil Piping Arrangement
Boilersmay be factorypackaged 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.
Do not use tankless coil if your water is excessively
hard with lime or other deposits which will
accumulate inside the coil.
When using tankless coil, boiler is configured so Honeywell
L7248 operates with Honeywell L4006 low limit mounted
on well installed in tankless heater. Mount factory wired low
limit on well.
Tempering valve (mixing valve) is recommended as shown
below. Flow restrictor may be required on tankless coil inlet
piping so that flow rates are matched to boiler heat input
(see table).
3EW.65
3EW.75
3EW1.00
4EW.90
4EW1.25
4EW1.50
5EW1.20
5EW1.75
91
105
140
126
175
210
168
245
!m
2.90
3.00
3.25
3.15
3.50
3.75
3.45
0.65
0.75
1.00
0.90
1.25
1.50
1.20
1.75 4.00
-1:Gallons of water per minute heated from 40 °F to 140°F with
200 °F boiler water temperature, intermittent draw
Water temperatures exceeding 125°F will cause
severe burns instantly or death by scalding.
Figure 11 =Tankless Coil Piping Arrangement
Lit,_TEMPERES H_T _TATER
AU OMAT]C D_SHWAt!tHER ECT
TEP PERED HOT
WATER
TAI', KLESS COIL
CENTER LINE
OF COLD TAP
LII'4IT
CBNTRBL
t
TEMPERING
VA VE
SHU T- OFF
VALVE
COLD WATER
ZNLET