# 21705453 Thermostat | Genuine Volvo Penta Part

## 🔧 Product Description

Wax-element coolant thermostat used on Volvo Penta TAD734GE and related Volvo D8K industrial engines. It regulates coolant flow between the engine and radiator to maintain the designed operating temperature.

## ⚙️ Key Features

-   Thermostat from the Cooling System group
-   0.184 kg
-   Supersedes 21360430
-   Recorded against 12 TAD series applications in the cost records

## 🔌 Function

Restricts coolant flow during warm-up and opens at the calibrated temperature to control engine operating temperature.

## ⚠️ Common Signs of Failure

-   Engine runs too cold
-   Temperature fluctuates
-   Thermostat stuck open or closed
-   Coolant leakage at the housing

## 🛠️ Service Notes

-   Renew the thermostat housing seal or gasket at the same time
-   Check the temperature sender and the gauge before condemning the thermostat, as a false reading mimics a stuck unit

## 🔄 Supersession & Cross Reference

### OEM Supersession Chain

-   21705453 → Supersedes 21360430 → Supersedes 21061992 → Supersedes 20914594

### OEM / Related Numbers

-   21360430 earlier number superseded by this part
-   21061992 earlier number superseded by this part
-   21033605 earlier number superseded by this part
-   20914594 earlier number superseded by this part

### Other-Brand OEM Numbers

-   VOE21705453
-   MAHLE: THD 6 86
-   Gates: TH63586G1
-   Behr Thermot-Tronik: THD 6 86

### Aftermarket / Verified Equivalents

-   NRF: 725017
-   Thermotec: D2RV005TT
-   Febi Bilstein: 171012
-   Auger: 99180
-   LEMA: 590586
-   Calorstat by Vernet: THCT19122.86
-   MTE-Thomson: VT629.86

## 📦 Condition

-   Genuine Volvo Penta part
-   Brand new
-   Supplied in original or equivalent packaging

## Details

- **Price:** 391.28 AUD
- **Vendor:** Volvo Penta
- **Type:** Cooling System
- **Tags:** Volvo Penta

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 391.28 AUD | In stock |

## Images

- 21705453 Thermostat | Genuine Volvo Penta Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/21705453-thermostat-genuine-volvo-penta)
> Updated: 2026-10-10