Troubleshooting; Overview - Toshiba MMW-AP0481CHQ-E Service Manual

8. TROUBLESHOOTING

8-1. Overview

(1) Before engaging in troubleshooting
(a) Applicable models
Super Heat Recovery Multi (SHRM-e) models.
(Indoor units: MMW-APOOO, Outdoor units: MMY-MAPOOOO*)
(b) Tools and measuring devices required
• Screwdrivers (Philips, flat head), spanners, long-nose pliers, nipper, pin to push reset switch, etc.
• Multimeter, thermometer, pressure gauge, etc.
(c) Things to check prior to troubleshooting (behaviors listed below are normal)
NO.
1 A compressor would not start
2 A pump would not start
An outdoor fan would not start or would
3
change speed for no reason
4 A pump would not stop
The air conditioner would not respond to a
5
start / stop command from a remote controller
6 The water temperature dose not increase
(2) Troubleshooting procedure
When a trouble occurs, proceed with troubleshooting in accordance with the procedure shown below.
Trouble
NOTE
Rather than a genuine trouble (see the List of Check Codes below), the problem could have been caused by a
microprocessor malfunction attributable to a poor quality of the power source or an external noise. Check for
possible noise sources, and shield the remote controller wiring and signal wires as necessary.
Behavior
Investigate check code
displayed on display of
remote controller
• Could it just be the 3-minute delay period (3 minutes after compressor
shutdown)?
• Could it just be the hot water module having gone thermostat OFF ?
• Could it just be the hot water module put on the timer ?
• Could it just be the system going through initial communication ?
• Could it just be out of the water temperature using range ?
Hot water module is not possible to operate when water temperatue
above 87˚C
• Could it just be defrosting operation ?
• Could it just be defrosting or under oil (refrigerant) recovery control ?
• Could it just be the hot water module operation under external controller ?
• Could it just be the water flow rate is out of using range ?
Using range of hot water module is rated ±15%
The check code is displayed.
The check code is not displayed.
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Possible cause
See the list of check codes
(below-mentioned)
See (3) When water does
not warm up (below-
mentioned)