I just recently bought my first ever Ford. 2015 Ford F-150 XLT Super Crew.

I noticed last night that my heater was blowing nice hot air and then it just started blowing cold air.
I then noticed that my fan was kicking on. I watched as my heater blew hot air, the thermostat
on my dash started to rise until about 3/4 to hot. My fan kicked on again and then my heater started to
blow cold air and when that switch happened, the thermostat went back down to half way between
cold and hot.

Then the cycle just kept repeating.

I have never seen anything like this happen where the heater was involved. I came from being a Dodge guy
and never had issues like this.

Any info or advice would be helpful!

Thanks

 

I bet your low on coolant or have an air pocket in it.

 

Low coolant does exactly this issue, regardless of motor type or manufacturer.

With you having 2 symptoms, cold discharge air and radiator cooling fans engaging, it sounds like the vehicle is in fact getting warmer. Look in your owners manual of how to check the coolant level, it should suggest where the level should be at cold. If you have been driving, do not investigate without exercising caution as the coolant tank may be warm, as are the surrounding areas.

It is not uncommon for the radiator fan to cycle, however you have recognized a pattern associated to the discharge air from the vents.

There are other possibilities but lets have you first start with checking the coolant level.

 

The cab radiator core is a high point in the cooling system. When coolant gets low, you will have it flowing through the cab core intermittently, hence your symptoms. When it gets low enough, none will flow through, and you get no heat.

Also when coolant is low, the level in the engine cooling radiator drops, losing cooling 'real estate'. It's the same as having a smaller radiator. Due to this, the system has lost some of it's ability to shed heat, so the coolant is hotter. The system kicks on the fans to remove more heat.

Two symptoms of the same problem. Did you find your radiator expansion tank empty?

 

I let my truck cool overnight and went out and checked the resubmit. It’s completely empty. I assume this is where the issue is coming from as you all mentioned before.

I will go and get coolant and let it sit till cold and the fill there’s pivot to max and hopefully this fixes the issues.

 

Now you will need to find out where it's going.
look for leaks. It doesn't evaporate it's a sealed system.

 

Actually it's perfectly normal for coolant to need to be topped off once or maybe twice a year; topped off not refill an empty coolant bottle. There is some evaporation of the water. If nothing has been done for 5 years the coolant bottle will probably be very low. However if the bottle was full when the OP purchased the truck he has a problem.

 

Just click --> FordTechMakuloco and he shows how to either use the proper tool or BURP the system

 

Whoever had it probably got rid of it for this reason. It has a leak and whoever sold it to you probably knows it. That's what people do and why I never by anything used anymore.