Hello! I have searched these forums to find someone with a similar problem but I have had no luck so sorry if this has been discussed before, I am new to this site and being a Jaguar owner!
My husband and I recently purchased an 05 Jaguar S-Type and we love it! It has its quirks and its a pain but none the less it's a great car. We have stumbled upon a problem we cant figure out and neither can our mechanic. Our heater will not turn on, no matter what I do. AC button stays on, even when the temp is turned up. Last winter was HELL, foggy windows were a massive pain. I had to stop the car several times while on my way to work just to clean off the fog and ice. I was also a human popsicle the entire time. I hated it. I'm new to car lingo as well. I have never worked on my own car but I am learning so please bear with me haha!
From my googling and trying to read up as much as I can, it sounds like a thermostat issue? My mechanic said I needed to have the whole thing reprogrammed and it would cost $500 and Id have to wait like 4 weeks to be able to use my air.... I'm desperate! Please help me! Thanks!

Welcome to the forum. Just wondering, did your mechanic recently get divorced and has expensive alimony payments to make? Kids in college? Something else expensive like that?

Please work through this troubleshooting guide:

https://www.jaguarforums.com/forum/s...ol-how-185002/


For no heat, do the steps in posts #2 and #6. I suspect your Dual Climate Control Valve (DCCV) is clogged or failed in the closed position. This blocks the flow of the hot coolant to the heater core. These tests will quickly verify this. You can do most of the troubleshooting yourself with just a thermometer.

Please keep us posted with what you find.

Welcome to the forum Anissa,

Your first step should be to read Karl's epic troubleshooting thread, https://www.jaguarforums.com/forum/s...ol-how-185002/
The ac is intended to be on even when heat is engaged to dry the air.

In additions to the suggestions from Karl and Norri above, find a different shop that's able to diagnose instead of guess. Guessing on a Jaguar can become very expensive very fast.

Anissa E, that link IS THE ANSWER for your heater problems. There is a ton of info in there and it will guide you to the root cause.

In my case I had temps that would change to full hot by itself. Here is the post I made for it -> https://www.jaguarforums.com/forum/s...r-dash-220296/


In your case the first thing I would do is to feel / measure the temps of the heater pipes running from the Dual Climate Control Valve (DCCV) back to the firewall (pass side). If you have hot pipe/hoses then you likely have a control problem. If they are not hot... you likely have a DCCV problem. (assuming fully warmed up engine)

The troubleshooting guide is the answer. It made diagnosing the no heat issue on my styper easy, albeit time consuming. Mine was simple and ended up being the relay for the secondary electric waterpump.