Volvo Penta KAD Thermostat. Two required for all KAD engines.

Your thermostat is an integral part of the cooling system and should be checked regularly for correct operation. Coolant should be changed, preferably with ready mixed, every 2 years and the heat exchanger removed for cleaning every 5 years.

Volvo Penta Part No: 3831424 - Two required 

For Volvo Penta Diesel Engines: 

KAD32, KAD32P, KAD32P-A
KAD42A, KAD42B, KAMD42A, KAMD42B
KAD300, KAMD300, KAD300-A, KAMD300-A, KAD43P, KAD43P-A, KAMD43P, KAMD43P-A
KAD44P, KAD44P-A, KAD44P-B, KAD44P-C, KAMD44EDC, KAMD44P, KAMD44P-B, KAMD44P-C

TAMD122A, TAMD122C, TAMD122D, AD31A, AQAD31A, TAMD31A, TMD31A

MD31A, MD31B, AD41B, AD41D, AD41L-A, AD41P, AD41P-A, AQAD41B

TAMD41B, TAMD41D, TAMD41M, TAMD41P, TAMD41P-A, TAMD41P-HD, TAMD42WJ-A, TMD41B, TMD41D , TMD41L-A, TMD41P-A, TAMD41H-A, TAMD41P-B, KAD42P, KAD42P-B, KAMD42P-A,
AD31B, AD31D, AD31L-A, AD31P-A, AD31X-D, AQAD31B, TAMD31B, TAMD31D

TAMD31L-A, TAMD31P-A, TAMD31S, TMD31B, TMD31L-A, TAMD31M, TAMD31P-B, TMD31D, TAMD122P, TAMD122P-A, TAMD122P-B, TAMD122P-C
AD41A, AQAD41A, AQD41A, D41A, TAMD41A, TMD41A