Rinnai FUA-E, Руководство по обслуживанию

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R. Water flow.
To operate there must be at least 2.4 l/min flowing through a Rinnai water heater. If
there is multiple heaters, installed without PAM valves or a MECS system then there
must be 2.4 l/min per heater. A modern wash hand basin could be as low as 3 or 4 l/
min, so if there is no means of staging the heaters they may not operate. Isolate all the
units except one to find out.
This problem could also crop up with a pumped secondary. Make sure the combination
of the pump capacity, and the staging of the units is compatible.
This problem often occurs when a non return valve in a mixing valves sticks in the open
position. Although the water flow at the taps will be good most of the water will be cold
water crossing over and shooting up the hot pipe.
The flow rate from your tap can be determined with a Weir cup, or a deluxe controller.
The deluxe controller manual explains the diagnostics function. If you are not getting
enough flow at an outlet, and you used to, check the filter (R.)
With the standard controller hold in the Temp Up button and push the Power button.
This will display the flow rate in litres per minute.
S. Gas Supply.
If the unit suddenly goes off you will need to check the gas supply. This is easy when
operating on natural gas, and is done by checking the inlet pressure. Other things to
check are the meter size, compared to other appliances total offtakes. If the unit has just
been installed there may be air in the line, be sure it is fully purged.
If the unit is on LPG make sure that you visually examine the tank or bottles to be sure
they are not freezing up. If they are then there is not enough gas. Check the regulators
to be sure they will pass enough gas for the system. Make sure the unit is operating with
a second stage regulator.
For both LPG and natural gas you will need to confirm that the gas pipe size is correct.
You may need to check the gas filter (F.)
T. Check anti frost heater components
The unit has three frost protection heaters mounted on the water pipes to protect them
from freezing. The heaters are white ceramic resistive heaters, and come on around 5°
C. The voltage through the heaters, when active, is 240Vac. The heaters are located as
follows. There is a valve heater in the mains incoming (where the flow sensor is) and
another valve heater in the outgoing hot water valve (next to the hot water thermistor.)
The third one is located on the front of the unit, at the top on the heat exchanger inlet
pipe.
Each heater element can be tested by measuring the resistance through them one at a
time.
The top heater resistance should be 50 – 60 k Ohms
Diagnostic Checks