No heat just cold air

Big lumps of metals and spanners. Including servicing and fluids.

Moderators: User administrators, Moderators

Post Reply
T25boy71
Posts: 65
Joined: 21 Jun 2019, 20:56
80-90 Mem No: 16913
Location: Weybridge
Contact:

No heat just cold air

Post by T25boy71 »

Seasons greetings all can anyone help having problems with the heater not getting hot on my Vw t25 it had a new heather matrix before we got it we have changed the rad and the heater switch just blows cold air could it be the ram air flap if so does anyone know the part number going to bleed it again today any ideas what else this could be got to have heat in the camper the pipes to and from the matrix are hot .
Vw T25 1.9 TD Z1 hightop rusty but Less rusty than when I got it. lol: 😊

User avatar
Aidan
Trader
Posts: 5258
Joined: 11 Oct 2005, 19:21
80-90 Mem No: 742
Location: Llanfyllin, mid Wales : )
Contact:

Re: No heat just cold air

Post by Aidan »

if the matrix is hot (is the pipe above the flow control valve as hot as below when the valve is open, rather than just heat soak in both the pipes below the valve) then you should get heat on recirculated air even if the fresh air flap isn't working; it's possible that when the matrix was replaced the heater box wasn't reassembled correctly, or the flow valve is stuck and the control cable is just bending rather than opening it - early heater boxes only produce cold air at the outer vents I believe, but centre and windscreen vents should be hot

davidoft1
Posts: 1482
Joined: 27 May 2009, 18:56
80-90 Mem No: 16628
Location: hayling island

Re: No heat just cold air

Post by davidoft1 »

First thing is to check the heater cable is actually moving the heater valve, the heater pipes can still be hot even with heater in the closed position as Aiden says due to heat soak and flow up to the valve , pull the Lowe dash plastic off , you can see the 2 pipes running into the heater , are they hot there ?

T25boy71
Posts: 65
Joined: 21 Jun 2019, 20:56
80-90 Mem No: 16913
Location: Weybridge
Contact:

Re: No heat just cold air

Post by T25boy71 »

Ok I removed the lower heater cowling and the 2 rubber hoses Both get hot, the heater box itself gets hot as well. 
The heater did work fine 2/3 weeks ago then when I turned the fan on full I Heard what sounded like a flap flip  No hot air Since then.
is there a flap to stop air going through the matrix? That I can get to/move without removing the dash for now.
i know I will have to remover the heater at some point to referb it as no foam on lower flap and this fell out See photo should be 4 of them and only 2 fitted.

I will have a look at the valve above the spare wheel to see if it moves as well.Image


 
Vw T25 1.9 TD Z1 hightop rusty but Less rusty than when I got it. lol: 😊

clone123
Posts: 372
Joined: 30 Oct 2015, 22:05
80-90 Mem No: 0
Location: Manchester

Re: No heat just cold air

Post by clone123 »

That's your clip there you may be able to pop it back in if you remove the cover that in front of the gear stick dont forget there is another clip on the other side

Sent from my SM-G955F using Tapatalk



Image

1985 RHD T25 hightop camper 1.9td 1Y engine
It's always easier with a friend

T25boy71
Posts: 65
Joined: 21 Jun 2019, 20:56
80-90 Mem No: 16913
Location: Weybridge
Contact:

Re: No heat just cold air

Post by T25boy71 »

The clip keeps popping out and it’s missing 2 clips, so need to Get holed of New ones.
ok I’ve had a look at the Heater valve and heater control it moves freely 
as for the pipes either side of the heater valve I can’t really feel any difference in temperature between them I don’t know how hot they should feel.
thinking about it the vans temperature on the Gage barely movers may need bleedIng.
Vw T25 1.9 TD Z1 hightop rusty but Less rusty than when I got it. lol: 😊

clone123
Posts: 372
Joined: 30 Oct 2015, 22:05
80-90 Mem No: 0
Location: Manchester

Re: No heat just cold air

Post by clone123 »

I dont no weather this is right but mine only blows hot air out of the top vent when I hold the revs up or go for a drive when on tick over it blows cold air out and Luke warm out of the bottom vent .
1985 RHD T25 hightop camper 1.9td 1Y engine
It's always easier with a friend

User avatar
steveo9007
Trader
Posts: 231
Joined: 21 May 2019, 17:49
80-90 Mem No: 16902
Location: Cornwall

Re: No heat just cold air

Post by steveo9007 »

i did my heater box recently and it took a while for mine to get hot for the first time of refitting, and i had to bleed it a few times, if you have the cover off the front, the one in front of the gearstick, you can stick your hand up through and feel the matrix on the inside to see if its getting warm, or feel the pipes feeding the matrix, after about 30 mins of running and bleeding i have heat and as i have refreshed  the foam strips it gets toasty inside my van a lot quicker than it did before. Also i ain't sure of the pipes to the heater matrix could be placed on wrong and the coolant running the wrong way round might have an effect  :shock:
1985 RHD Pop Top Autosleeper, 1.7D KY Engine 4 Speed ALD Gearbox (Bertie)

T25boy71
Posts: 65
Joined: 21 Jun 2019, 20:56
80-90 Mem No: 16913
Location: Weybridge
Contact:

Re: No heat just cold air

Post by T25boy71 »

Update I’ve bleed the system 4 times did get a bit of air heating a bit better but still not hot as it should be and the temperature gauge still only just goes  Into the first white block so isn’t getting up to temperature to start the cooling fan.
question could my problem be the thermostat?
Vw T25 1.9 TD Z1 hightop rusty but Less rusty than when I got it. lol: 😊

User avatar
ajsimmo
Trader
Posts: 2084
Joined: 23 Mar 2009, 14:06
80-90 Mem No: 6542
Location: Isle of Arran
Contact:

Re: No heat just cold air

Post by ajsimmo »

Yes.
I recommend you change the stat.

Sent from my ONEPLUS A3003 using Tapatalk

The Campershack - Just T3s
WBX Rebuilds, Upgrades & Engine conversions

T25boy71
Posts: 65
Joined: 21 Jun 2019, 20:56
80-90 Mem No: 16913
Location: Weybridge
Contact:

Re: No heat just cold air

Post by T25boy71 »

Ok will order one it comes with rubber seal is there any other gaskets needed and Where is the thermostat located On the waterpump?
thanks
Vw T25 1.9 TD Z1 hightop rusty but Less rusty than when I got it. lol: 😊

User avatar
steveo9007
Trader
Posts: 231
Joined: 21 May 2019, 17:49
80-90 Mem No: 16902
Location: Cornwall

Re: No heat just cold air

Post by steveo9007 »

T25boy71 wrote: 15 Dec 2020, 11:38 Ok will order one it comes with rubber seal is there any other gaskets needed and Where is the thermostat located On the waterpump?
thanks

It’s inside the water pump you have to take apart to get at it.
1985 RHD Pop Top Autosleeper, 1.7D KY Engine 4 Speed ALD Gearbox (Bertie)

Dueller
Posts: 8
Joined: 18 Nov 2020, 12:17
80-90 Mem No: 0

Re: No heat just cold air

Post by Dueller »

Ive been through all this and concluded the engine isn't right so will change the head gasket when i pull it this month for some jobs

Is it using water is the big question and there is a good thread on the other forum re bleeding it off, works bang on

Its a real unknown engine despite being a Vege recon at some point but there's defo something not right

I've flushed it through,new waterpump, new 'stat, bled it till i bled tears, pulled the dash, flushed the matrix, rebuilt flap controls so  everything that's all the usual suspects

Was driving the other day and smelt rusty water if that makes sense so its got to be a head off as there's no leak, oil is fine and it will sometimes use water and other times not, nowhere else for it to go as the matrix is pressure tight

As a kid i used to fit Golf motors into beetles and we removed the stat and partially blocked the hose from pump to head, forcing the water round the system, worked a treat even in 40' heat! Very very nearly thought about doing this to my Doka but engine first then i will see
1989 Crewcab 1600TD JX
4 Speed

Post Reply