Baxi NTC Sensor 720789201 Replacement

The Baxi NTC sensor 720789201 measures water temperature accurately to keep your boiler running smoothly. Therefore, it helps maintain stable heating and consistent hot water delivery. Moreover, this brand new NTC sensor supports precise temperature control and reduces the risk of overheating or temperature fluctuations. As a result, it improves comfort, efficiency, and system reliability during daily use.

Compatibility :

Baxi Combi: 624, 630, 636, 825, 830, 836, 24, 28, 40
Duo Tec 2 (GA Range): 24, 28, 33, 40
Ecoblue Advance Combi: 24, 28, 33, 40
Advance Combi ErP: 24, 28, 33, 40
Platinum 2 Combi (GA): 28, 33, 40

Important fitting advice

We recommend that all parts are fitted by a fully qualified Gas Safe registered engineer. If you need help confirming the right part, contact us our team has 10+ years of boiler spares knowledge and friendly chat support to help you quickly.

Delivery

At Boiler Spares Hub, we dispatch orders within 1 working day (Monday-Friday). Orders placed outside working days will be dispatched on the next working day. For delivery options available for this product, please add it to your basket or check our delivery options page.

Returns

We accept 30-day returns. Returns must be in an unopened, sealed box. If we find the item has been used or installation was attempted, we may refuse the return.

Frequently Asked Questions (FAQ’s)

1.What is the function of an NTC sensor
NTC means Negative Temperature Coefficient. An NTC thermistor works as a temperature sensor and measures temperature by changing resistance as temperature changes.

2.What is the maximum temperature for NTC
The NTC element has a total length of 16 mm and a maximum diameter of 1.8 mm. It supports an operating temperature range from minus 40 C to plus 600 C. You can extend the maximum temperature to 650 C for 1000 hours. The rated resistance is defined at 200 C with minimum tolerance.

3.What is the NTC fault on a boiler
A boiler can show an NTC fault when the hot water NTC sensor fails. This sensor measures hot water temperature. When it fails, it can cause boiler faults and may trigger the A7 error code. A defective flow and safety sensor can also trigger the A7 error code.

4.What are the 4 types of temperature sensors
The four main types are thermocouples, resistance temperature detectors, thermistors, and semiconductor IC sensors. Each type offers different benefits in accuracy, range, cost, and durability.

5.How to read NTC value
The rated zero power resistance value means the resistance of the NTC thermistor at 25 C. This value is the nominal resistance. For example, at 25 C, the NTC 5D 9 thermistor has a nominal resistance of 5 ohms.