Fixed Multiple Issues But Still Blowing Cold Air?

petrohl34d · Dec 2nd, 2019, 11:39

Still no hot air after each of these fixes.

Temperature gauge was going most of the way up but not reaching the centre of the dial so I changed the thermostat and now it is going to the middle and staying there.

I've changed the pollen filter.
Flushed the system.
Recalibrated the CCM with Vida.

Any ideas?

VOLVOBOY · Dec 2nd, 2019, 13:21

Hi.
The heater matrix is a full-flow system so the hot water circulates continuously. If there is no hot water then there is no heat. So an issue
with the water pump ( low impetus) is a possibility. Most likely is an air-lock or a blockage in the lines from the pump or the matrix itself is blocked.
Remove the under glove-box trim again and with the engine running and fully up to temperature feel the two rubber bulkhead hoses and aluminium pipes that go to/from the matrix.
They should both be hot to roughly the same temp. If one is hot (latent heat)and the other cold then the matrix is restricted. If both are cold then the problem lies in the lines to the matrix.

Georgeandkira · Dec 2nd, 2019, 13:51

A radiator "leak-stop" product can clog a heater core completely.

A grey putty like compound did so in a family member's car.

After disconnecting the system hoses I used scraps of hose and a funnel to coax various cleaners into the core

Gasoline was the only solvent which worked.

petrohl34d · Dec 2nd, 2019, 13:54

Thanks guys!

I will check this this evening an let you konw.

brutusmotorsport · Dec 2nd, 2019, 15:14

are your heater pipes actually attached to the matrix and not by passed? if they are by passed you wouldn't get any heat any way.

Georgeandkira · Dec 2nd, 2019, 19:01

If a heater matrix leaked I could MAYBE see someone bypassing it as the cheapest "fix" possible...but that's a big maybe.

Who would do that?

petrohl34d · Dec 3rd, 2019, 08:37

I checked the pipes and the bottom one is definitely hotter than the top one, so it looks like it's a blocked heater matrix.

I have a new one ordered, so will replace and let you know.

Fingers crossed it fixes it.

That's 3/3 of the Volvos I've owned which have had heater matrix problems ffs!

VOLVOBOY · Dec 3rd, 2019, 11:00

"I checked the pipes and the bottom one is definitely hotter than the top one"
Hi.
If the top pipe is cold then there is no flow so the matrix is probably blocked.
If there is heat in both pipes then there is flow. It could just be the heat control flap is not working.
I did say that both pipes should be roughly the same temp. This would be with the heater fan off and the controls set to cold.
With the heater set to max and the blower on the matrix should give up its heat and the temp difference in the pipes more noticeable.
As changing the matrix is a pig of a job I would have disconnected the bulkhead hose fittings, attached a hose and back flushed the matrix in both directions. Then check the heater flap operation.

petrohl34d · Dec 3rd, 2019, 11:12

Great advice, thanks! I'll back flush it this evening.

The heater flaps seem to be working fine, as I can hear the motors operating when I turn the temperature control from hot to cold.

VOLVOBOY · Dec 3rd, 2019, 16:21

Hi.
Yeah. The motors might be working but are they operating the flaps?
Motors 7 & 8 are the left and right heater flap , and 6 is ventilation.

Dec 2nd, 2019, 11:39	#1
petrohl34d Senior Member Last Online: Jan 30th, 2023 20:21 Join Date: Jan 2016 Location: Enniskillen	Fixed Multiple Issues But Still Blowing Cold Air? Still no hot air after each of these fixes. Temperature gauge was going most of the way up but not reaching the centre of the dial so I changed the thermostat and now it is going to the middle and staying there. I've changed the pollen filter. Flushed the system. Recalibrated the CCM with Vida. Any ideas? __________________ 1998 Volvo V70 2.5 TDi - Dead @ 326,000 miles 1999 Volvo V70 2.5 TDi - Dead @ 250,000 miles 2005 Volvo XC70 2.4 D5 - Current daily

Dec 2nd, 2019, 13:51	#3
Georgeandkira Premier Member Last Online: Yesterday 20:28 Join Date: Feb 2009 Location: Hackensack	A radiator "leak-stop" product can clog a heater core completely. A grey putty like compound did so in a family member's car. After disconnecting the system hoses I used scraps of hose and a funnel to coax various cleaners into the core Gasoline was the only solvent which worked. Last edited by Georgeandkira; Dec 2nd, 2019 at 14:02. Reason: added details

Dec 2nd, 2019, 13:54	#4
petrohl34d Senior Member Last Online: Jan 30th, 2023 20:21 Join Date: Jan 2016 Location: Enniskillen	Thanks guys! I will check this this evening an let you konw. __________________ 1998 Volvo V70 2.5 TDi - Dead @ 326,000 miles 1999 Volvo V70 2.5 TDi - Dead @ 250,000 miles 2005 Volvo XC70 2.4 D5 - Current daily

Dec 2nd, 2019, 15:14	#5
brutusmotorsport Junior Member Last Online: Dec 23rd, 2023 10:45 Join Date: Nov 2019 Location: guildford	heater are your heater pipes actually attached to the matrix and not by passed? if they are by passed you wouldn't get any heat any way.

Dec 3rd, 2019, 08:37	#7
petrohl34d Senior Member Last Online: Jan 30th, 2023 20:21 Join Date: Jan 2016 Location: Enniskillen	I checked the pipes and the bottom one is definitely hotter than the top one, so it looks like it's a blocked heater matrix. I have a new one ordered, so will replace and let you know. Fingers crossed it fixes it. That's 3/3 of the Volvos I've owned which have had heater matrix problems ffs! __________________ 1998 Volvo V70 2.5 TDi - Dead @ 326,000 miles 1999 Volvo V70 2.5 TDi - Dead @ 250,000 miles 2005 Volvo XC70 2.4 D5 - Current daily Last edited by petrohl34d; Dec 3rd, 2019 at 08:50.

Dec 2nd, 2019, 13:21	#2
VOLVOBOY Lazy Member Last Online: Yesterday 21:31 Join Date: Mar 2007 Location: HORLEY	Hi. The heater matrix is a full-flow system so the hot water circulates continuously. If there is no hot water then there is no heat. So an issue with the water pump ( low impetus) is a possibility. Most likely is an air-lock or a blockage in the lines from the pump or the matrix itself is blocked. Remove the under glove-box trim again and with the engine running and fully up to temperature feel the two rubber bulkhead hoses and aluminium pipes that go to/from the matrix. They should both be hot to roughly the same temp. If one is hot (latent heat)and the other cold then the matrix is restricted. If both are cold then the problem lies in the lines to the matrix.

Dec 2nd, 2019, 19:01	#6
Georgeandkira Premier Member Last Online: Yesterday 20:28 Join Date: Feb 2009 Location: Hackensack	If a heater matrix leaked I could MAYBE see someone bypassing it as the cheapest "fix" possible...but that's a big maybe. Who would do that?

Dec 3rd, 2019, 11:00	#8
VOLVOBOY Lazy Member Last Online: Yesterday 21:31 Join Date: Mar 2007 Location: HORLEY	"I checked the pipes and the bottom one is definitely hotter than the top one" Hi. If the top pipe is cold then there is no flow so the matrix is probably blocked. If there is heat in both pipes then there is flow. It could just be the heat control flap is not working. I did say that both pipes should be roughly the same temp. This would be with the heater fan off and the controls set to cold. With the heater set to max and the blower on the matrix should give up its heat and the temp difference in the pipes more noticeable. As changing the matrix is a pig of a job I would have disconnected the bulkhead hose fittings, attached a hose and back flushed the matrix in both directions. Then check the heater flap operation.

Dec 3rd, 2019, 11:12	#9
petrohl34d Senior Member Last Online: Jan 30th, 2023 20:21 Join Date: Jan 2016 Location: Enniskillen	Great advice, thanks! I'll back flush it this evening. The heater flaps seem to be working fine, as I can hear the motors operating when I turn the temperature control from hot to cold. __________________ 1998 Volvo V70 2.5 TDi - Dead @ 326,000 miles 1999 Volvo V70 2.5 TDi - Dead @ 250,000 miles 2005 Volvo XC70 2.4 D5 - Current daily

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