New thermostat, now no cabin heat!

[Dave]

Hi all, I have changed my thermostat today and now I have no heat in the cabin! Assuming I need to bleed the system. 1.8T
What’s the best and easiest way to bleed it. Thanks

[WillyHeckaslike]

Welcome to the site. Just out of interest, where in the engine bay is the stat that you changed located?

[dave lincs]

Yes it needs bleeding, there is a bleed screw on the coolant rail pipe under the throttle body if stuck message me as I'm not far from you

[trikey]

Originally Posted by dave lincs

Yes it needs bleeding, there is a bleed screw on the coolant rail pipe under the throttle body if stuck message me as I'm not far from you

This is a good option, I'd have a drive to Daves and get it bled properly.

Sent from my SM-G780G using Tapatalk

[Dave]

Originally Posted by dave lincs

Yes it needs bleeding, there is a bleed screw on the coolant rail pipe under the throttle body if stuck message me as I'm not far from you

Thanks very much. I will attempt to sort it today. If no joy I will let you know. Thanks again!

[Dave]

Originally Posted by WillyHeckaslike

Welcome to the site. Just out of interest, where in the engine bay is the stat that you changed located?

At the bottom of the rad… passenger side.

[SD1too]

Originally Posted by Dave

At the bottom of the rad… passenger side.

Ahh, that's a PRT; Pressure Relief Thermostat. What was the reason for renewing this Dave? Was the engine running too cool or too hot, or was it just a heater problem?

Have you just bought this car? If so, is there any history of work on the cooling system?

Simon

[Dave]

Originally Posted by SD1too

Ahh, that's a PRT; Pressure Relief Thermostat. What was the reason for renewing this Dave? Was the engine running too cool or too hot, or was it just a heater problem?

Have you just bought this car? If so, is there any history of work on the cooling system?

Simon

Yeah the Hester matrix wasn’t getting hot only bottom pipe was hot so I removed it and flushed it! Put a new thermostat on just as a matter of cause really. Initially before a put a new stat on the heater was working after a flush out! But cooling fan was kicking in after driving the car. So that’s main reason for replacing the stat. Yes there is history and I haven’t had it long. It has suffered a head gasket failure in the past but this has all been replaced and sorted, under previous ownership.


After I have bled the system today if the heater works and cooling fan still comes on…. What else could it be??

[SD1too]

Thanks for the information Dave.

One of the guiding principles that I've learnt over a lifetime of car repairs is: "if it ain't broke, don't fix it". I therefore wouldn't replace a thermostat "as a matter of course", only if there was evidence to suggest that it was faulty.

You say that the radiator fan was running "after driving the car". If this was a run at, say, 50 mph or more followed by low speed manoeuvring at your house, whereupon the fan started, then that isn't necessarily a fault.
On the other hand if "after driving the car" means that the fan started, or continued to run after stopping the engine then that needs investigating by activating the digital coolant temperature display in the instrument pack.

I thought that there might have been work by the previous owner so thanks for confirming that. If your bleeding operation doesn't solve it then check that someone hasn't incorrectly fitted a standard thermostat in addition to the PRT.

Let's hope it's just air though. Do you have the official procedure to follow?

Simon

[WillyHeckaslike]

The reason I asked about the location of the stat is to be certain that you were aware of the two different types of stat and their different locations that Rover used on the 1.8 variants. Some have not been aware and have ended up with two stats fitted as a result, a PRT at the radiator and a standard traditional stat under the inlet manifold. Only one should be fitted and when two are unwittingly fitted it does tend to lead to problems. There could be a number of causes and given that the car is a fairly recent acquisition and it came to you with previous HGF work having been done I wouldn't rule out any of them just yet - two stats included. The first logical step should be to ensure that the cooling system is properly configured, I wouldn't want to check for two stats just yet but I would check that the prt stat has been connected correctly as a mistake with this is not unknown. Link to a diagram of how it should be. Click