Navien
Navien Thermistor Heat Exchanger (Red Wire) 30012907A
Navien heat exchanger thermistor with red wire, part 30012907A, for LCB 700 combi, regular and system boilers.
At a glance
- Appliance family: LCB 700
£5.57
£4.64 ex. VAT · VAT at 20%
Same-day dispatch
Ordered by 4pm Mon–Fri, 10:30am Sat.
30-day returns
Unused, in original packaging.
What it is
The Navien heat exchanger thermistor (red wire), part number 30012907A, is a temperature sensing component used on Navien LCB 700 series boilers. It monitors heat exchanger temperature and feeds that reading back to the boiler's control board. The red wire identifies this variant within the thermistor range.
Signs this part needs replacing
- Boiler locks out or shuts down with a temperature-related fault code
- Heating or hot water temperature fluctuates instead of holding steady
- Control board reports implausible or erratic heat exchanger readings
- Boiler short-cycles as the thermistor misreads heat exchanger temperature
- Visible damage, corrosion or a broken wire at the thermistor or its connector
Before you order
- Confirm your boiler model and serial number against the fitment list above
- Check the wire colour on the existing thermistor matches the red wire specified here
- Compare the part number on the existing component with 30012907A
- Inspect the connector and wiring loom for damage before fitting a replacement
No specification data held for this part.
| Make | Model / assembly | Reference | Years | Fitment |
|---|---|---|---|---|
| NAVIEN LCB 700 COMBI EXTERNAL 21KW (Serial Number 1705) | — | — | — | |
| NAVIEN LCB 700 COMBI EXTERNAL 21KW (Serial Number 1705) | — | — | — | |
| NAVIEN LCB 700 COMBI EXTERNAL 28KW (Serial Number 1710) | — | — | — | |
| NAVIEN LCB 700 COMBI EXTERNAL 28KW (Serial Number 1710) | — | — | — | |
| NAVIEN LCB 700 COMBI EXTERNAL 36KW (Serial Number 1709) | — | — | — | |
| NAVIEN LCB 700 COMBI EXTERNAL 36KW (Serial Number 1709) | — | — | — | |
| NAVIEN LCB 700 COMBI INTERNAL 21KW (Serial Number 1704) | — | — | — | |
| NAVIEN LCB 700 COMBI INTERNAL 21KW (Serial Number 1704) | — | — | — | |
| NAVIEN LCB 700 COMBI INTERNAL 28KW (Serial Number 1706) | — | — | — | |
| NAVIEN LCB 700 COMBI INTERNAL 28KW (Serial Number 1706) | — | — | — |
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Documents & drawings
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