Use and Care Manual

33
The DHW is cold when only a
single xture is open.
• The unit will not heat the water if the ow rate is less than
0.4 gallons (1.5L) per minute.
* Minimum activation ow rate : 0.4 GPM (1.5L/min)
Minimum operating ow rate : 0.29 GPM (1.1L/min)
Open the xture more or open other xtures so that a greater ow
passes through the unit, and the unit should begin heating again.
Amount of DHW
The amount of DHW at a certain
xture is not constant.
• When hot water is demanded at other xtures, the amount
available may be reduced. The maximum ow available from
NRCB199DV (GHQ-C3201WX-FF US) and
NRCB180DV(GHQ-C2801WX-FF US) are 8.4 GPM (32L/min.)
and 7.5GPM (28.2L/min.), respectively at a 45°F (25°C)
temperature rise.
• Pressure uctuations and other plumbing conditions can
cause the temperature and pressure at a xture to be
unstable, but it should stabilize after a short time.
• There are some types of hot water taps that discharges
large volumes of hot water at rst but stabilize after time.
• To keep the temperature stable, the unit limits the amount
of water that can ow through it to a small amount initially,
but the amount increases over time.
Amount of DHW available has
decreased over time.
Fluctuations in DHW temperatures.
• Set water temperature at 115°F to 120°F or 48°C (118°F) to
50°C (122°F). This will allow you to use a higher ow of hot
water thus meeting the minimum ow requirement of 0.29 GPM
(1.1L/min.).
* Minimum activation ow rate : 0.4 GPM (1.5L/min)
Minimum operating ow rate : 0.29 GPM (1.1L/min)
• Clean the water lter of any debris. ( p.29)
(Continued)
DHW temperature setting cannot rise.
• Is the maximum temperature setting appropriate? ( p.20)
• Is the water lter clogged? (
p.29)
• If the supply water is hard and has not been treated,
scale can build-up in the Combi Boiler and decrease
the maximum amount of hot water available. Scale can
be removed from the Combi Boiler by ushing the unit
periodically. To prevent scale from forming in the Combi
Boiler, a water softener or scale inhibitor is recommended.