Other Errors - Rinnai Q85SN Installation & Servicing Instructions Manual

16.4 Other Errors

Complaint
Central heating but no
domestic hot water
Hot water but no central
heating
Central heating
installation gets hot
without being requested
Insuffi cient quantity of
hot water
Temperature drop of the
DHW (Combi)
Description
1. -Key of the DHW program is not
switched on
2. Cylinder sensor or thermostat defective.
3. When using RS100
4. Three-port valve is not circulating to
DHW
1. -Key of the central heating program
is not switched on.
2. Room thermostat (on/off) is not giving
any signal to the boiler.
3. RS100 with outdoor sensor
(Room sensor-On)
4. Three-port valve is not circulating to
central heating position.
1. -Key pump program is on.
2. Dirt in three-port valve or three-port valve
cartridge is binding.
3. Expansion tank incorrectly fi tted.
1. Hot and cold water connection to the
boiler mixed up.
2. Incorrect fl ow reducing valve.
3. In the absence of positive results
1. Flow reducing valve
2. Thermostatic mixing valve incorrectly set. Adjust (by measuring the temperature)
3. DHW power for the boiler is set too low.
Solution
Switch on DHW program on the Control Tower
Replace cylinder sensor or thermostat
- Check timer times for DHW program,
if necessary reset
- RS100 does not respond to DHW program
- See RS100 installation instructions
- Check wiring.
- If necessary replace the three-port valve
motor.
Switch on central heating program
Check room thermostat
- Outdoor temperature is higher than 70°F,
depending upon the Eco-temperature set
(70°F is the default). Check Info chapter
Step 7 or temperature is higher than the
Eco temperature set (see RS100 installation
instructions).
- Check timer program and set room
temperature.
Check wiring, replace the three-port valve
motor.
Switch off.
Clean or replace.
Connect expansion tank between three-port
valve and pump (for Combi boiler or Solo with
external DHW tank this pipe connection is
present as standard).
Check left = cold, right = hot
- Check for the type and for contamination, if
necessary replace (Combi) and/or clean.
- Check the comfort synchronising valve for
the correct setting in accordance with the
installation instructions.
Check for lime scale. If necessary descale or
replace
Check fl ow reducing valve for the correct type
in accordance with the installation instructions
-Check PARA chapter Step No. 43
- Check the functioning and wiring of the
DHW sensor T3.
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