00
DAYS 00
HRS 00
MIN 00
SEC
DAYS 00
HRS 00
MIN 00
SEC
Sierra
Sierra Thermostat Kit #18-3648
$32.60
$38.91
Sierra 18-3648 Thermostats & PartsThermostat KitCooling: ThermostatsSierra Thermostat Kit #18-3648Normalized SKU: 183648UPC Code: 808282258825
00
DAYS 00
HRS 00
MIN 00
SEC
DAYS 00
HRS 00
MIN 00
SEC
Sierra
Sierra Thermostat Kit #18-3647
$37.94
$45.52
Sierra 18-3647 Thermostats & PartsThermostat KitOEM Interchange:MERCURY MARINE: 807252Q5Cooling: ThermostatsSierra Thermostat Kit #18-3647Normalized SKU: 183647UPC Code: 808282101213
00
DAYS 00
HRS 00
MIN 00
SEC
DAYS 00
HRS 00
MIN 00
SEC
Sierra
Sierra Thermostat #18-3649
$25.92
$30.93
Sierra 18-3649 Thermostats & PartsThermostatOEM Interchange:CRUSADER: 97895MERCURY MARINE: 807252-2Cooling: ThermostatsSierra Thermostat #18-3649Normalized SKU: 183649UPC Code: 808282258832
00
DAYS 00
HRS 00
MIN 00
SEC
DAYS 00
HRS 00
MIN 00
SEC
Sierra
Sierra Thermostat #18-3645
$27.23
$32.50
Sierra 18-3645 Thermostats & PartsThermostatOEM Interchange:CHRYSLER INBOARD: 2463441Cooling: ThermostatsSierra Thermostat #18-3645Normalized SKU: 183645UPC Code: 808282105853
00
DAYS 00
HRS 00
MIN 00
SEC
DAYS 00
HRS 00
MIN 00
SEC
Sierra
Sierra Thermostat Kit #18-3646
$32.80
$39.15
Sierra 18-3646 Thermostats & PartsThermostat KitOEM Interchange:MERCURY MARINE: 807252Q3Cooling: ThermostatsSierra Thermostat Kit #18-3646Normalized SKU: 183646UPC Code: 808282100919
00
DAYS 00
HRS 00
MIN 00
SEC
DAYS 00
HRS 00
MIN 00
SEC
Sierra
Sierra Thermostat Kit #18-3644
$33.36
$39.81
Sierra 18-3644 Thermostats & PartsThermostat KitCooling: ThermostatsSierra Thermostat Kit #18-3644Normalized SKU: 183644UPC Code: 808282105549
00
DAYS 00
HRS 00
MIN 00
SEC
DAYS 00
HRS 00
MIN 00
SEC
Sierra
Sierra Thermostat Kit #18-3569
$31.39
$37.46
Sierra 18-3569 Thermostats & PartsThermostat KitOEM Interchange:MERCURY MARINE: 803061T1Cooling: ThermostatsSierra Thermostat Kit #18-3569Normalized SKU: 183569UPC Code: 808282112899
00
DAYS 00
HRS 00
MIN 00
SEC
DAYS 00
HRS 00
MIN 00
SEC
Sierra
Sierra Rubber Valve #18-3567
$0.53
$0.62
Sierra 18-3567 Thermostats & PartsRubber ValveOEM Interchange:OMC: 321221Sierra Rubber Valve #18-3567Normalized SKU: 183567UPC Code: 808282243999
00
DAYS 00
HRS 00
MIN 00
SEC
DAYS 00
HRS 00
MIN 00
SEC
Sierra
Sierra Thermostat Kit #18-3568
$27.85
$33.24
Sierra 18-3568 Thermostats & PartsThermostat KitOEM Interchange:MERCURY MARINE: 99155T1Cooling: ThermostatsSierra Thermostat Kit #18-3568Normalized SKU: 183568UPC Code: 808282112783
00
DAYS 00
HRS 00
MIN 00
SEC
DAYS 00
HRS 00
MIN 00
SEC
Sierra
Sierra Retainer #18-3565
$7.12
$8.38
Sierra 18-3565 Thermostats & PartsRetainerOEM Interchange:OMC: 321220Sierra Retainer #18-3565Normalized SKU: 183565UPC Code: 808282258788
00
DAYS 00
HRS 00
MIN 00
SEC
DAYS 00
HRS 00
MIN 00
SEC
Sierra
Sierra Poppet Relief Valve #18-3564
$3.54
$4.16
Sierra 18-3564 Thermostats & PartsPoppet Relief ValveOEM Interchange:OMC: 318395Sierra Poppet Relief Valve #18-3564Normalized SKU: 183564UPC Code: 808282234294
00
DAYS 00
HRS 00
MIN 00
SEC
DAYS 00
HRS 00
MIN 00
SEC
Sierra
Sierra Valve Cup #18-3562
$2.48
$2.92
Sierra 18-3562 Thermostats & PartsValve CupOEM Interchange:OMC: 321222Sierra Valve Cup #18-3562Normalized SKU: 183562UPC Code: 808282243975
00
DAYS 00
HRS 00
MIN 00
SEC
DAYS 00
HRS 00
MIN 00
SEC
Sierra
Sierra Poppet Relief Valve #18-3563
$0.58
$0.68
Sierra 18-3563 Thermostats & Parts
Poppet Relief Valve
OEM Interchange:OMC: 321027
Normalized SKU: 183563UPC Code: 808282234287
00
DAYS 00
HRS 00
MIN 00
SEC
DAYS 00
HRS 00
MIN 00
SEC
Sierra
Sierra Vernatherm #18-3560
$28.33
$33.82
Sierra 18-3560 Thermostats & PartsVernathermOEM Interchange:OMC: 384719Sierra Vernatherm #18-3560Normalized SKU: 183560UPC Code: 030999563040
00
DAYS 00
HRS 00
MIN 00
SEC
DAYS 00
HRS 00
MIN 00
SEC
Sierra
Sierra Thermostat #18-3559
$41.52
$49.82
Sierra 18-3559 Thermostats & PartsThermostatOEM Interchange:CHRYSLER FORCE: F528068Cooling: ThermostatsSierra Thermostat #18-3559Normalized SKU: 183559UPC Code: 030999563033
00
DAYS 00
HRS 00
MIN 00
SEC
DAYS 00
HRS 00
MIN 00
SEC
Sierra
Sierra Thermostat #18-3561
$18.31
$21.85
Sierra 18-3561 Thermostats & PartsThermostatOEM Interchange:OMC: 436195Cooling: ThermostatsSierra Thermostat #18-3561Normalized SKU: 183561UPC Code: 030999753656
00
DAYS 00
HRS 00
MIN 00
SEC
DAYS 00
HRS 00
MIN 00
SEC
Sierra
Sierra Thermostat #18-3557
$34.39
$41.05
Sierra 18-3557 Thermostats & PartsThermostatOEM Interchange:CHRYSLER FORCE: F335068MERCURY MARINE: 47594OMC: 382385OMC: 396987VOLVO: 21148403Cooling: ThermostatsSierra Thermostat #18-3557Normalized SKU: 183557UPC Code: 030999563019
00
DAYS 00
HRS 00
MIN 00
SEC
DAYS 00
HRS 00
MIN 00
SEC
Sierra
Sierra Thermostat #18-3556
$38.69
$46.18
Sierra 18-3556 Thermostats & PartsThermostatOEM Interchange:CHRYSLER FORCE: F97068-2Cooling: ThermostatsSierra Thermostat #18-3556Normalized SKU: 183556UPC Code: 030999563002
00
DAYS 00
HRS 00
MIN 00
SEC
DAYS 00
HRS 00
MIN 00
SEC
Sierra
Sierra Thermostat #18-3558
$34.16
$40.77
Sierra 18-3558 Thermostats & PartsThermostatOEM Interchange:OMC: 3853799OMC: 982554Cooling: ThermostatsSierra Thermostat #18-3558Normalized SKU: 183558UPC Code: 030999563026
00
DAYS 00
HRS 00
MIN 00
SEC
DAYS 00
HRS 00
MIN 00
SEC
Sierra
Sierra Thermostat #18-3554
$34.16
$40.77
Sierra 18-3554 Thermostats & PartsThermostatOEM Interchange:OMC: 383307Cooling: ThermostatsSierra Thermostat #18-3554Normalized SKU: 183554UPC Code: 030999316028
Frequently Asked Questions
First Choice Marine is an online marine retailer carrying a diverse line of marine parts and accessories and related items from industry-respected and demanded manufacturers and suppliers. Through our diverse distributor network, we are able to access over 150,000 items, including our current site inventory, new products being added, and special order items. If you need it on your boat... we are your one-stop shop!
Yes, we offer FREE Shipping on most orders over $149 to US-48*.
Each product displays a shipping status message, just above the item price. Below is the meaning for each of these codes.
- Qualifies for Free Shipping: This item qualifies for free shipping when the order is $149+
- Qualifies for Free Ground Shipping: This item qualifies for free ground shipping when the order is $149+.
- Oversized - Not Qualified for Free Shipping: This item is too large/heavy to qualify for free shipping
- Hazardous Item - Not Qualified for Free Shipping: This item is hazardous and does not qualify for free shipping
- Truck Freight - Not Qualified for Free Shipping: This item has to be shipped via truck freight. Please contact us for a quote
- In-Store Pickup Only: This item can only be picked up in our Grain Valley, MO retail store
Below the price of the item, on the product page, there is a message indicating the availability of the product.
The quantity on hand is updated as inventory events happen and matches what we have available. If you have urgent needs and we are close to what you need, contact us, and we can confirm stock.
We offer a hassle-free return policy. If you're not completely satisfied with your purchase, you can return it within 30 days for a full refund or exchange.
If you need to return an item, please follow the guidelines here so we can process a prompt refund and assist you in finding the correct item.
Free Shipping
On most orders $149+ to the continental 48 US states.Secure Shopping
Fast, secure checkout with a variety of payment methods.Shop with confidence
25+ years serving the marine industry.Support center
Need help? Contact us via live chat, phone, or email.