Instructions / Assembly

2) PLUMBING HOOK-UP
NOTE: DO NOT install this heater in a location that is subject to freezing
temperatures
1) The unit is supplied with compression fittings. USE THESE: DO NOT
USE THREADED PIPE FITTINGS. DO NOT USE PIPE DOPE
OR TEFLON TAPE ON THIS INSTALLATION. Ensure the inlet filter supplied
with this unit is in place.
2) Take care to ensure that the pipes are correctly aligned with the inlet and
outlet bosses in order to avoid excessive stress on the heater body molding.
NOTE: Run water through the supply pipe to remove all debris from the
pipe before connecting the heater. Failure to do so could damage the flow
switch.
3) Install isolating valves (full flow ball valve type) on both inlet and outlet
pipes. This allows unit to be isolated for maintenance purposes. (Fig. 2)
4) When all plumbing is complete, fully check the system for water leaks
at all plumbing connections. If leak is present take corrective action. If leak
is at the compression fitting, slowly tighten compression nut until it stops.
Ensure compression fittings are tightened to 18FT.LB. Fully open both inlet
and outlet ball valves.
Run all hot water outlets fed by this heater one at a time for a minute or two
until the water flow is continuous, free from “gulping” and from all visible air
pockets.
NOTE:
ALL PLUMBING MUST BE COMPLETED BEFORE YOU
PROCEED WITH THE ELECTRICAL HOOK-UP.
TEST THE INSTALLATION FOR LEAKS BEFORE
CONNECTING THE ELECTRICAL SUPPLY.
4) COMMISSIONING YOUR HEATER
IMPORTANT
Before switching “on” the power at the breaker make sure that the hot
water circuit is free of air pockets or premature failure of the heating element will occur.
To do this open all hot water faucets one at a time for a minute or two until the water flow
is continuous and free from “gulping” and from visible air pockets.
1) With inlet and outlet BALL VALVES fully open, turn on all hot water outlets.
2) Run for 5 minutes, turning faucet “on” and “off” repeatedly.
3) Switch on electric supply at breaker.
4) The power indicator light should now come on with water flowing. (see Fig. 1).
At this point water temperature will begin to rise to a maximum temperature
of 105⁰F and stabilize.
5) Check performance of flow switch by opening and closing outlet valve a few times.
The power indicator light should be on ONLY when water is flowing through the unit.
6) It is possible that drawing off cold water at comparatively high rates of flow
elsewhere in the building at the same time that the heater is working, could
cause premature element failure. Care should be taken not to starve the unit
of cold water. To prevent this from happening, open fully the main valve on
the cold supply to the building and throttle back the control valves to the other
cold water outlets.
7) AccuMix heaters are capable of heating water proportionally to their power
rating and will heat water to 105⁰F #so long as the flow rate for the desired temperature
rise is not exceeded. Since the outlet temperature is 105⁰F, the temperature rise
that is needed depends on the inlet water temperature. For example, if the supply water
temperature is 60⁰F, the temperature rise will be 45⁰F. Therefore the
maximum attainable flow rate can be calculated with a 45⁰F rise.
1 1/2 “
Hot outlet
compression
fitting
DO NOT
SOLDER
Cold inlet
compression
fitting
DO NOT
SOLDER
Fig 1
Inlet filter
MODEL RATING (kW) FLOW (GPM) TEMP. RISE (⁰F)
MB004120T 3.5 0.53 45⁰F
MB005240T 4.8 0.73 45⁰F
MB007240T 6.5 0.99 45⁰F
MB010240T 9.5 1.44 45⁰F
MB012240T 11.5 1.75 45⁰F
MB008277T 8.0 1.21 45⁰F
MB010277T 10.0 1.52 45⁰F