S60-D5 Blowing HOT & cold intermitantly.

[ArtyH]

Hello, I am new to the forum. I live in the U.K, we are experiencing a bit of bad weather at this time and this has shown me that I have a problem with my heating system. I have recently bought the car (its a 2005 SE 2.4 model) and did not notice the heating problem at the time of purchase and think the recent cold weather may be a factor.
The problem is when the heater is turned up to max and or any other setting the blower emits both hot air for about 3 seconds and then cold air for the same time. This result in the car reaching only a moderate interior temperature. The temp gauge reads halfway and is steady.

I have read a thread concerning the replacement of the thermostat -
https://www.matthewsvolvosite.com/forums ... 9&t=25928-
and wondered if it was the temp stat or the engine coolant temp sensor that could be the problem?

Any advice would be greatly appreciated.
Kind regards,

ArtyH.

[confused_al]

...The temp gauge reads halfway and is steady

That doesn't sound like you have a bad ETC or t-stat problem.

The problem is when the heater is turned up to max and or any other setting the blower emits both hot air for about 3 seconds and then cold air for the same time.

That sounds like you have an ECC (Electronic Climate Control) issue, assuming thats what you have. I'm sorry, wish could be more help but that is way over my head.

[ArtyH]

@ confused_al thanks for the reply info. Thought it would not be straight forward, looks like it need some cash thrown at the job, just my luck.

Thanks again for the reply.

[andymoore]

I also have the same problem that happened at the same time in the Uk!!

I have a 2005 s60 T5 that now blows hot and cold every 3 secods with a pump sounding noise!!

Wonder if it is the extreme cold that has caused it?

Let me know if you get a resolve and I will do the same