Auburn, WA: Suite A, 420 H St NW, Auburn, WA 98001 / Phone: 253-245-5400


Mon - Fri: 8am - 5pm


Spokane, WA: Suite A, 5815 W. Thorpe Road, Spokane, WA 99224 / Phone: 509-571-9002

Heavy Truck, RV, and Fleet Repair Services

Truck Repair Services



Mon - Fri: 8am - 5pm

Auburn, WA: Suite A, 420 H St NW, Auburn, WA 98001 / Phone: 253-245-5400

Spokane, WA: Suite A, 5815 W. Thorpe Road, Spokane, WA 99224 / Phone: 509-571-9002

In the winter, shivering away in your cabin is the last thing you want to do. At Motorplex, we offer regular truck and fleet maintenance to stop heating problems before they start, but sometimes troubleshooting on the road is necessary.

Step one is always figuring out what your heating issue could be so you know if you can fix it or need to bring it in for repair. Here, we highlight some common semi-truck heater issues to help you identify problems.

Know How Your Truck’s Heater Works

It may seem counter-intuitive, but did you know your heating system is a cooling system? Your heating system uses coolant (just like your cooling system does). The only difference is that truck heating systems heat coolant instead of cooling it down.

Here’s how it works: When you turn your heater on, the coolant in your heating system moves through the heater core of your truck (which is inside your dashboard). This process ends with hot air pushing through your vents and heating your cabin.

So Why Isn’t My Heater Working?

There are a variety of reasons why you may be having semi-truck heater issues. Here we list three.

Low on Coolant

When there’s not enough coolant in your truck, your truck’s heating system won’t be able to send coolant through the heating core to warm up. When you turn on your heat, cold air may come out at first, and that’s normal. If it’s been more than a few minutes, though, and you’re still getting cold air, this is a sign you need to check your coolant. When coolant levels are low, fill up your engine’s coolant to prevent this issue.

Broken or stuck Thermostat

Your thermostat is part of what controls the coolant flowing through your radiator. With semi-truck heating systems, sometimes the issue is that your thermostat is either stuck or malfunctioning. You’ll know this is the case if you can see your thermostat always stays at the same place regardless of what you’re doing. Once you’ve identified this problem, fixing it is simple. Thermostats are inexpensive and easy to install.

Possible Leak

Your truck may lose coolant when there’s a leak. Coolant moves through various places in your engine, so there could be a leak here. Two of the most common places for this are your water pump and hoses.

Another place that can leak coolant is your radiator. If your coolant levels are low, check your radiator. A radiator leak is never something to ignore.

Call Motorplex!

We are on hand to fix your semi-truck heating issues. We can also schedule regular service and fleet maintenance to catch any issues before they become a problem. We have shops in Spokane and Auburn, WA and specialize in heavy truck repairs. We also offer mobile on-site repairs.

Call us today!

Motorplex has shops in Auburn and Spokane, WA, with skilled and experienced teams at both locations. Contact Motorplex today!

Need professional fleet maintenance? Then Motorplex is here to help. Contact us now to book an appointment in Auburn, WA or Spokane, WA!

For all your maintenance and trailer repairs, Motorplex is here to help! They have shops in Auburn and Spokane, WA, for service anytime you need them.

Call us to set up a schedule for your truck fleet maintenance!

• Spokane: 509-571-9002
• Auburn: 253-245-5400