Domestic Hot Water Performance And Piping - Burnham MINUTEMAN II Installation, Operating And Service Instructions

IV. Domestic Hot Water Performance and Piping
A
. Domestic hot water ratings for the Minuteman
based two 5 minute draws with 10 minute recovery
period at 100°F average temperature rise. Refer to
Table 1 for ratings.
Table 1: Domestic Hot Water Ratings
Boiler Model Water Draw
MMII4-70
MMII4-105
MMII5-105
MMII5-140
B
. Drain domestic water system.
1. Shut off cold water supply at main shutoff valve.
2. Open 1 or more system faucets to relieve pressure.
Open system drain valve, leaving faucets open to
relieve vacuum.
3. Disconnect exiting domestic hot water heating
system ( if applicable).
C
. Connect hot water piping to ½" NPT outlet of heater.
See Figure 7.
WARNING
Install an automatic mixing valve (tempering
valve) at the tankless heater outlet to avoid risk of
burns or scalding due to excessively hot water at
fixtures. Adjust and maintain the mixing valve in
accordance with the manufacturer's instructions.
D
. Connect cold water piping to ½" NPT inlet of heater.
See Figure 7.
II are
®
Pressure Drop
(GPM) (PSI)
2.9 14
3.1 16
3.1 16
3.3 18
Figure : Domestic Hot Water Piping
NOTICE
Domestic water temperature has the potential to
exceed the desired temperature during a space
heating cycle.
E
. Fill domestic hot water system.
1. Open all faucets to allow air to purge from heater
and piping.
2. Open domestic hot water shutoff valve (if used).
3. Open cold water inlet shutoff valve.
4. Purge air from domestic water system. Close
faucets.
5. Check system for leaks. Repair as necessary.