Hi can anyone shed some light on how this works, and what exactly is it supposed to do.

I have had no heater since xmas as i thought the matrix was leaking into the cabin. But have now found this not to be the case. So today i re-connected the pipes back to the heater control valve. I did however, before connecting all the pipes, connect the valve up and turn on the ignition and the heater. But the valve did not turn or click. Heat is circulating from the engine through the heater and there is no leaks. So i was wondering what is the valve supposed to do.??? 

I've had to replace two, one failed closed so it diverted hot water through the valve not through the matrix, so no heat, the other failed open so we had heat all the time, annoyingly we had no heat in winter and only heat in the summer lol.

best way to check the solenoid is working is to have the car on, heater dual to hot and take the plug on and off at the valve, it's a very quite click, think you can feel it more than hear it.

if that isn't working it could be the heater panel that's faulty.

I've responded in the duplicate thread.

• 
• Budding Enthusiast
•  9
• 42 posts
• Name: Andy
• Ford Model: Fiesta
• Ford Year: 1999
• UK/Ireland Location: Norfolk

• Report post
•  
•  

Posted just now

hi thanks for the info about this. I will check it out in the morning, have noticed that the heater gets really hot then it goes luke warm . It is now running quite cold. What would happen if i bypassed it completely. ??

Bypass the valve? You'll have heat on all the time (providing the valve is faulty and not something else).

The fact it goes hot then cold suggests to me you either have an air pocket in the matrix or your coolant reservoir tank is low. Check the coolant and bleed the cooling system if necessary.

I am assuming the bypass is just a temporary measure in advance of a permanent fix. 

The varying temperatures are a classic symptom of an (intermittent) sticking solenoid.

Have bled the system and put fresh anti-freeze mix in, and it still made no difference to the lack of heat. So i have removed the hcv and replaced with a couple of pieces of pipe. This is a temporary measure, once i have purchased a new one, it will be put back to how it should be. 

Thanks all for the advice.